MARS

AND ITS CANALS

BY

PERCIVAL LOWELL

director of the observatory at flagstaff, arizona; non-resident professor of astronomy at the massachusetts institute of technology ; fellow of the american academy of arts and sciences; mkmbre de la socirte a*tkonomiyue de france; member of the astronomical and astro- physical society of america; mitglied der astrunom ische oe- sellschaft; membre de la societh beloe d'astronomie; honorary member of the socikdad abtronomica de mex ico; jans8en medalist of the sociktk abtkonomiqc k de france, 1904, for researches on mars; etc., etc.

ILLUSTRATED

Neto gotfe

THE MACMILLAN COMPANY

LONDON; MACMILLAN & CO., Ltd.

1906

All riyhttt rtterved
JULY 13. !»»•

Copyright, 1906,

By THE MACMILLAN COMPANY.

Set up aud elcctrotypcd. Published December, 1906.

Nottosot JDrraa J. S. Cushlng Jc Co. — Berwick & Smith Co. Norwood, Mass., U.9.A.
2To

G. V. SCHIAPARELLI

THE COLUMBUS OF A NEW PLANETARY WORLD

THIS INVESTIGATION UPON IT

IS APPRECIATIVELY

INSCRIBED

PREFACE

Eleven years have elapsed since the writer's first

work on Mars was published in which were recorded

the facts gleaned in his research up to that time

and in which was set forth a theory of their explana

tion. Continued work in the, interval has confirmed

the conclusions there stated ; sometimes in quite

unexpected ways. Five times during that period

Mars has approached the earth within suitable scan

ning distance and been subjected to careful and

prolonged scrutiny. Familiarity with the subject,

improved telescopic means, and long-continued train

ing have all combined to increased efficiency in the

procuring of data and to results which have been

proportionate. A mass of new material has thus

been collected, —some of it along old lines, some of

it in lines that are themselves new, —and both have

led to the same outcome. In addition to thus push

ing inquiry into advanced portions of the subject,

study has been spent in investigation of the reality

of the phenomena upon which so much is based, and

in testing every theory which has been suggested to

vii
viii PREFACE

account for them. From diplopia to optical inter

ference, each of these has been examined and found

incompatible with the observations. The phenomena

are all they have been stated to be, and more. Each

step forward in observation has confirmed the genu

ineness of those that went before.

To set forth science in a popular, that is, in a

generally understandable, form is as obligatory as to

present it in a more technical manner. If men are

to benefit by it, it must be expressed to their com

prehension. To do this should be feasible for him

who is master of his subject and is both the best

test of, and the best training to, that post. Espe

cially vital is it that the exposition should be done

at first hand ; for to describe what a man has him

self discovered comes as near as possible to making

a reader the co-discoverer of it. Not only are thus

escaped the mistaken glosses of second-hand knowl

edge, but an aroma of actuality, which cannot be

filtered through another mind without sensible evap

oration, clings to the account of the pioneer. Nor

is it so hard to make any well-grasped matter com

prehensible to a man of good general intelligence as

is commonly supposed. The whole object of science

is to synthesize, and so simplify ; and did we but

know the uttermost of a subject we could make it

singularly clear. Meanwhile technical phraseology,
PREFACE ix

useful as shorthand to the cult, becomes meaningless

jargon to the uninitiate and is paraded most by the

least profound. But worse still for their employ

symbols tend to fictitious understanding. Formulae

are the anaesthetics of thought, not its stimulants ;

and to make any one think is far better worth while

than cramming him with ill-considered, and therefore

indigestible, learning.

Even to the technical student, a popular book, if

well done, may yield most valuable results. For noth

ing in any branch of science is so little known as its

articulation, —how the skeleton of it is put together,

and what may be the mode of attachment of its

muscles.

Preface

CONTENTS

PARR vii

PART I

NATURAL FEATURES rHAPTERI. On Exploration 8

II. A Departi:re-point 12

III. A Bird's,eye View of Past Martian Discovery 20

IV. The Polar Caps 32

V. Behavior of the Polar Caps .... 41

VI. Martian Polar Expeditions 54

VII. White Spots 78

VIII. Climate and Weather S2

IX. Mountains and Cloud 00

X. The Blue-green Areas 108

XI. Vegetation 119

XII. Terraqueousness and Teruestriality . . 128

XIII. The Reddish,ochre Tracts 148

XIV. Summary 159

PART II

NON-NATURAL FEATURES

XV. The Canals 17=5

XVI. Their System 184

XVII. Gemination of the Canals 192

I. The Diplopic Theory 190

II. The Interference Theory .... 201

III. The Illusion Theory 202 xi
xii CONTENTS

CHAPTER PAGE XVIII. The Double Canals 204

XIX. Canals in the Dark Regions .... 243

XX. Oases 24!)

XXI. Carets on the Borders of the Great Dia

phragm 265

XXII. The Canals Photographed ... . . . 271

PART III

THE CANALS IN ACTION

XXIII. Canals: Kinematic 281

XXIV. Canal Development Individually Instanced . 304

XXV. Hibernation of the Canals .... 313

XXVII. XXV Oases: Arctic Canals Kinematicand Polar Rifts . . . 32530

PART IV

EXPLANATION

XXVIII. Constitution of the Canals and Oases . . 337

XXIX. Life 348

XXX. Evidence 300

XXXI. The Husbanding of Water 366

XXXII. Conclusion 376

INDEX 3*5
LIST OF ILLUSTRATIONS

PLATES

Mars' Hill Frontispiece

PACK The Hermitage 8

The San Francisco Peaks 18

Martian Maps ry :

I. Beer and Maedler. 1840 26

II. Kaiser. 1864 26

III. Flammarion (Resume). 1876 .... 27

IV. Green. 1877 27

V. SchiaparellI. 1877 28

VI. Sciiiaparkll1. 1879 28

VII. SchIAPArellI. 1881 29

VIII. SChIAPArellI. 1884 29

IX. Lowell. 1894 . . 30

X. Lowell. 1896 30

XI. Lowell. 1901 31

XII. Lowell. 1905 31

South Polar Cap, 1905 42

North Polar Cap, 1905 44

Mare Erythraeum, Martian hate, Decemher 30 . . 120

Mare Krythraeum, Martian date, January 16 . . 122

Mare Erythraeum, Martian date, Fehruary 1 . . 124

Mare Erythraeum. Martian date, February 21 . . 120

Mars, on Mercator's Projection 384

South Polar CUTS Cap in APPEARING winter IN TEXT 56

Hellas in winter 59 xiii
xiv LIST OF ILLUSTRATIONS

PAfil White south of Nectar and Solis Lacus .... 59

Northern Cap hooded with vapor 64

Northern Cap unmasked 65

Deposition ok frost 70

First northern snow 72

White in Elysium 75

White in the Tons Hectoris 78

Projection on terminator 101

Lines in dark area 117

Map of North America at the close of Archa:an time 132

North America at opening of Upper Silurian period . 134

Map of North America after the Appalachian revo

lution 135

North America in the Cretaceous period . . . 136

NorththeAmerica, Tertiaryshowing era the parts under water in 137

Earth's Desert Areas, Western Hemisphere . . . 156

Earth's Desert Areas, Eastern Hemisphere . . . 157

Showing the Eumenides-Orcus 183

Martian douules 206

Martian doubles 207

Mouths of Euphrates and Phison. June, 1003 . . 219

Peculiar development of the Ganges .... 228

Djihoun, the narrowest double 229

The Sabaeus Sinus, embouchure for the double HidDEKEL AND GlHON 232

The Propostis, 1905 247

Fons Immortalis, June 19 254

Utopia Regio. 1903 256

Ascraeus Lucus and Gioas. March 2, 1903 . . . 258

Peculiar association ok the Luci Ismenii with double

canals 260

Lucus Ismenius. March, 1903 262

Showing seasonal change. I 285
LIST OF ILLUSTRATIONS xv

I' AGE Showing seasonal change. II 285

Mean Canal Cartouches 298

Showing development of the Brontes:

I. February 25 306

II. March 30 307

III. April 3 307

IV. May 4 308

V. May 7 308

VI. July 18 30!)

Cartouches of the Brontes 311

Amenthes alone in February 319

Amentiies feebler and still alone in March . . . 319

Appearance of Thoth with Triton and curved Nepen

thes. Amenthes vanished, April 20 ... 320

Advent of the Lucus Moeris. May 29 ... 321

Amenthes with Thoth-Nepenthes. July .... 322

Cartouches of Amenthes, Thoth, and their combina

tion . 828

Phenology Curves — Earth 342

Phenology Curves — Mars 343

PART I

NATURAL FEATURES

MARS AND ITS CANALS

CHAPTER I

ON EXPLORATION

liTROM time immemorial travel and discovery

have called with strange insistence to him who,

wondering on the world, felt adventure in his veins.

The leaving familiar sights and faces to push forth into

the unknown has with magnetic force drawn the bold

to great endeavor and fired the thought of those who

stayed at home. Spur to enterprise since man first

was, this spirit has urged him over the habitable globe.

Linked in part to mere matter of support it led the

more daring of the Aryans to quit the shade of their

beech trees, reposeful as that umbrage may have been,

and wander into Central Asia, so to perplex philolo

gists into believing them to have originated there;

it lured Columbus across the waste of waters and

caused his son to have carved upon his tomb that

ringing couplet of which the simple grandeur still

stirs the blood : —

A Castilla y a Leon

N. tiKvo moxdo mo Colon ;

(To Castile and Leon beyond the wave

Another world Columbus gave;)

3
4 MAES AND ITS CANALS

it drove the early voyagers into the heart of the vast

wilderness, there to endure all hardship so that they

might come where their kind had never stood before;

and now it points man to the pole.

Something of the selfsame spirit finds a farther

field today outside the confines of our traversable

earth. Science which has caused the world to shrink

and dwindle has been no less busy bringing near what

in the past seemed inaccessibly remote. Beyond our

earth man's penetration has found it possible to pierce,

and in its widening circle of research has latterly been

made aware of another world of strange enticement

across the depths of space. Planetary distances, not

mundane ones, are here concerned, and the globe to be

explored, though akin to, is yet very different from,

our own. This other world is the planet Mars.

Sundered from us by the ocean of ether, a fellowmember of our own community of matter there makes

its circuit of the sun upon whose face features show

which stamp it as cognate to that on which we live.

In spite of the millions of miles of intervening matterless void, upon it markings can be made out that

distantly resemble our earth's topography and grow

increasingly suggestive as vision shapes them better;

and yet among the seemingly familiar reveal aspects

which are completely strange. But more than this :

over the face of it sweep changes that show it to be
CHAP. I ON EXPLORATION 5

not a dead but a living world, like ours in this, and

luring curiosity by details unknown here to further

exploration of its unfamiliar ground.

To observe Mars is to embark upon this enterprise;

not in body but in mind. Though parted by a gulf

more impassable than any sea, the telescope lets us

traverse what otherwise had been barred and lands us

at last above the shores we went forth to seek. Real

the journey is, though incorporeal in kind. Since the

seeing strange sights is the essence of all far wander

ings, it is as truly travel so the eye arrive as if the body

kept it company. Indeed, sight is our only far viatic

sense. Touch and taste both hang on contact, smell

stands indebted to the near and even hearing waits on

ponderable matter where sound soon dissipates away;

only sight soars untrammeled of the grosser adjunct of

the flesh to penetrate what were otherwise unfathom

able space.

What the voyager thus finds himself envisaging

shares by that very fact in the expansion of the sense

that brought him there. No longer tied by means of

transport to seas his sails may . compass or lands his

feet may tread, the traveler reaches a goal removed in

kind from his own habitat. He proves to have ad

ventured, not into unknown parts of a known world,

but into one new to him in its entirety. In extent

alone he surveys what dwarfs the explorer's conquests
6 MARS AND ITS CANALS CHAP. I

on Earth. But size is the least of the surprises there

in store for him. What confronts his gaze finds com

monly no counterpart on Earth. His previous knowl

edge stands him in scant stead. For he faces what is

so removed from every day experience that analogy no

longer offers itself with safety as a guide. He must

build up new conceptions from fresh data and slowly

proceed to deduce the meaning they may contain.

Science alone can help him to interpretation of what

he finds, and above all must he wean himself from

human prejudice and earthbound limitation. For he

deals here with ultramundane things. With just

enough of cosmogony in common to make decipher

ment not despairable this world is yet so different

from the one he personally knows as to whet curiosity

at every turn. He is permitted to perceive what

piques inquiry and by patient adding of point to point

promises at last a rational result.

Like mundane exploration, it is arduous too; ad

astra per aspera is here literally true. For it is a

journey not devoid of hardship and discomfort by the

way. Its starting-point preludes as much. To get

conditions proper for his work the explorer must forego

the haunts of men and even those terrestrial spots found

by them most habitable. Astronomy now demands

bodily abstraction of its devotee. Its deities are gods

that veil themselves amid man-crowded marts and
chap, I ON EXPLOITATION 7

impose withdrawal and seclusion for the prosecution of

their cult as much as any worshiped for other reason

in more primeval times. To see into the beyond re

quires purity; in the medium now as formerly in the

man. As little air as may be and that only of the

best is obligatory to his enterprise; and the securing it

makes him perforce a hermit from his kind. He must

abandon cities and forego plains. Only in places raised

above and aloof from men can he profitably pursue

his search, places where nature never meant him to

dwell and admonishes him of the fact by sundry

hints stand ofa mile a more and ora half less nearer distressing the stars character. is not Toto .

stand immune.

Thus it comes about that today besides its temples

erected in cities, monasteries in the wilds are being

dedicated to astronomy as in the past to faith ; mon

asteries made to commune with its spirit, as temples

are to communicate the letter of its law. Pioneers in

such profession, those already in existence are but the

precursors of many yet to come as science shall more

and more recognize their need. Advance in knowl

edge demands what they alone can give. Primitive,

too, they must be as befits the still austere sincerity

of a cult, in which the simplest structures are found

to be the best.

Still the very wildness of the life their devotee is
8 MAES AND ITS CANALS

forced to lead has in it a certain fittingness for his post

in its primeval detachment from the too earthbound,

in concept as in circumstance. Withdrawn from con

tact with his kind, he is by that much raised above

human prejudice and limitation. To sally forth into

the untrod wilderness in the cold and dark of a

winter's small hours of the morning, with the snow feet

deep upon the ground and the frosty stars for mute

companionship, is almost to forget one's self a man

for the solemn awe of one's surroundings. Fitting

portal to communion with another world, it is through

such avenue one enters on his quest where the com

mon and familiar no longer jostle the unknown and

the strange. Nor is the stillness of the stars invaded

when some long unearthly howl, like the wail of a lost

soul, breaks the slumber of the mesa forest, marking

the prowling presence of a stray coyote. Gone as it

came, it dies in the distance on the air that gave it

birth; and the gloom of the pines swallows up one's

vain peering after something palpable, their tops alone

decipherable in dark silhouette against the sky. From

amid surroundings that for their height and their

intenancy fringe the absolute silence of space the

observer must set forth who purposes to cross it to

another planetary world.

But the isolation of his journey is not always so for

bidding. His coming back is no less girt with grandeur
 

CHAP. I ON EXPLORATION 9

of a different though equally detached a kind. Even

before the stars begin to dim in warning to him to re

turn, a faint suffusion as of half-suspected light creeps

into the border of the eastern sky. Against it, along

the far pine-clad horizon, mesa after mesa in shaggy

lines of sentineling earth, stands forth dark marshaled

in the gloom, informed with prescience of what is soon

to come. Imperceptibly the pallor grows, blanching

the face of night and one by one extinguishing the stars.

Slowly then it takes on color, tingeing ever so faintly

to a flush that swells and deepens as the minutes pass.

One had said the sky lay dreaming of the sun in pale

imagery at first that gathers force and feeling till the

dreamer turns thus rosy red in slumbering supposition

of reality. Then the blush dies out. The crimson fades

to pink, the pink to ashes. The stars have disappeared

and yet it is not day. It is the supreme moment of the

dawn, the hush with which the Earth awaits its full

awakening. For now again the color gathers in the east,

not with the impalpable suffusion it had before but

nearer and more vivid. No longer reflectively remote,

rays imminent of the sun strike the upper air, the most

adventurously refrangible turning the underside of a

few stray clouds into flame-hued bars of glowing metal.

They burn thus in the silent east first red, then orange,

and then gold, each spectral tint in prismatic reve

lation coming to join the next till in a sudden
10 MARS AND ITS CANALS

blinding burst of splendor the solar disk tops the

horizon's rim.

Not less impressive is the journey when the afternoon

watch has replaced the morning vigil by the drawing of

the planet nearer to the sun. Lost in the brilliance of

the dazzling sky, the planet lies hid from the senses'

search. The quest were hopeless did not the mind guide

the telescope to its goal. To theory alone is it visible

still, and so to its predicted place the observer sets his

circles, and punctual to the prophecy the planet swings

into the field of view. One must be dulled by long

routine to such mastery of mind not to have the act

itself clothe with a sense of charmed withdrawal the

object of his quest.

So much and more there are of traveler's glimpses

by the way, compensation that offsets the frequent dis

comfort, and even balking of his purpose by inoppor

tune cloud. For the best of places is not perfect, and a

storm will sometimes rob him of a region he wished to

see. He must learn to wait upon his opportunities and

then no less to wait for mankind's acceptance of his

results; for in common with most explorers he will

encounter on his return that final penalty of penetra

tion, the certainty at first of being disbelieved.

In such respect he will be even worse off than were the

other world discoverers of the fifteenth and sixteenth

centuries. For they at least could offer material proof
CHAP. I ON EXPLOKATION 11

of things that they had seen. Dumb Indians and gold

spoke more convincingly than the lips of the great navi

gators. To astronomy, too, that other world was due.

Without a knowledge of the earth's shape and size got

from Francisco of Pisa, Columbus had never adventured

himself upon the deep. But more than this, an as

tronomer it was, in the person of Americus Vespueius,

who first discovered the new world, by recognizing it

as such ; Columbus never dreaming he had lighted upon

a world that was new. Nor does it impair one jot or

tittle of his glory that he knew it not. Nothing can

deprive him of the imperishable fame of launching

forth into the void in hope of a beyond, though he

found So, not curiously, what hehassought it beenbutwith something the trans-etherian. stranger still.

To Schiaparelli the republic of science owes a new and "

vast domain. His genius first detected those strange

new markings on the Martian disk which have proved

the portal to all that has since been seen, and his courage

in the face of universal condemnation led to explora

tion of them. He made there voyage after voyage,

much as Columbus did on Earth, with even less of rec

ognition from home. As with Columbus, too, the full

import of his great discovery lay hid even to him and

only by discoveries since is gradually resulting in rec

ognition of another sentient world.
CHAPTER II

A DEPARTURE-POINT

A S the character of the travel is distinctive, so the

outcome of the voyage is unique. If he choose his

departure-point aright, the observer will be vouchsafed

an experience without parallel on Earth. To select

this setting-out station is the first step in the journey

upon which everything depends. For it is essential

to visual arrival that a departure-point be taken where

definition is at its best. Now, so far as our present

knowledge goes, the conditions most conducive to

good seeing turn out to lie in one or other of the two

great desert belts that girdle the globe. Many of us

are unaware of the existence of such belts and yet they

are among the most striking features of physical geog

raphy. Could we get off our globe and view it from

without we should mark two sash-like bands of coun

try, to the poleward side of either tropic, where the sur

face itself lay patently exposed. Unclothed of verdure

themselves they would stand forth doubly clear by con

trast. For elsewhere cloud would hide to a greater or

less extent the actual configuration of the Earth's

topography to an observer scanning it from space.

12
A DEPARTURE-POINT 13

One of these sash-like belts of desert runs through

southern California, Arizona, New Mexico, the Sahara,

Arabia Petrsea and the Desert of Gobi; the other

traverses Peru, the South African veldt, and Western

Australia. They are desert because in them rain is

rare; and even clouds seldom form. In a twofold

way they conduce to astronomic ends. Absence of

rain makes primarily for clear skies and secondarily

for steady air; and the one of these conditions is no

less vital to sight than the other. Water vapor is a

great upsetter of atmospheric equilibrium and com

motion in the air the spoiler of definition. Thus from

the cloudlessness of their skies man finds in them most

chance of uninterrupted communion with the stars,

while by suitably choosing his spot he here obtains as

well that prime desideratum for planetary work, as

near a heavenly equanimity in the air currents over

his head as is practically possible.

From the fact that these regions are desert they are

less frequented of man, and the observer is thus perforce

isolated by the nature of the case, the regions best

adapted to mankind being the least suited to astronomic

observations. In addition to what nature has thus

done in the matter, humanity has further differentiated

the two classes of sights by processes of its own contriv

ing. Not only is civilized man actively engaged in de

facing such part of the Earth's surface as he comes in
14 MARS AND ITS CANALS CHAP. II

contact with, he is equally busy blotting out his sky.

In the latter uncommendable pursuit he has in the last

quarter of a century made surprising progress. With a

success only too undesirable his habitat has gradually

become canopied by a welkin of his own fashioning,

which has rendered it largely unfit for the more delicate

kinds of astronomic work. Smoke from multiplying

factories by rising into the air and forming the nucleus

about which cloud collects has joined with electric

lighting to help put out the stars. These concomitants

of advancing civilization have succeeded above the

dreams of the most earth-centred in shutting off sight

of the beyond so that today few city-bred children

have any conception of the glories of the heavens

which made of the Chaldean shepherds astronomers in

spite of themselves.

The old world and the new are alike affected by

such obliteration. Long ago London took the lead

with fogs proverbial wholly due to smoke, fine parti

cles of solid matter in suspension making these points

of condensation about which water vapor gathers to

form cloud. With the increase of smoke-emitting

chimneys over the world other centres of population

have followed suit till today Europe and eastern North

America vie with each other as to which sky shall be

the most obliterate. Even when the obscuration is not

patent to the layman it is evident to the meteorologist
A DEPARTURE-POINT 15

or astronomer. By a certain dimming of the blue,

smoke or dust reveals its presence high up aloft as

telltalely as if the thing itself were visible. Some time

since the writer had occasion to traverse Germany in

summer from Gottingen to Cologne and in so doing was

impressed by a cloudiness of the sky he felt sure had not

existed when he knew it as a boy. For the change

was too startling and extensive to be wholly laid to the

score of the brighter remembrances of youth. On

reaching Cologne he mentioned his suspicion to Klein,

only to find his own inference corroborated; observa

tions made twenty years ago being impracticable today.

Two years later in Milan Celoria told the same story,

the study of Mars having ceased to be possible there for

like cause. Factory smoke and electric lights had com

bined to veil the planet at about the time Schiaparelli

gave up his observations because of failing sight. With

a certain poetic fitness the sky had itself been blotted

just at the time the master's eye had dimmed.

America is not behind in this race for sky extinction.

In the neighborhood of its great cities and spreading into

the country round about the heavens have ceased to be

favorable to research. Not till we pass beyond the

Missouri do the stars shine out as they shone before the

white man came.

Few astronomers even fully appreciate how much this

means, so used does man get to slowly changing condi
16 MARS AND ITS CANALS CHAP. II

tions. It amounts, indeed, between Washington and

Arizona to a whole magnitude in the stars which may

be seen. At the Naval Observatory of the former

sixty-four stars were mapped in a region where with a

slightly smaller glass one hundred and seventy-two were

charted at Flagstaff.

Besides their immediate use as observing stations

these desert belts possess mediate interest on their own

account in a branch of the very study their cloudlessness helps to promote, the branch here considered, the

study of the planet Mars. They help explain what they

permit to be visible. For in the physical history of the

Earth's development they are among the latest phe

nomena and mark the beginning of that stage of world

evolution into which Mars is already well advanced.

They are symptomatic of the passing of a terraqueous

globe into a purely terrestrial one. Desertism, the state

into which every planetary' body must eventually come

and for which, therefore, it becomes necessary to coin a

word, has there made its first appearance upon the

Earth. Standing as it does for the approach of age

in planetary existence, it may be likened to the first

gray hairs in man. Or better still it corresponds to

early autumnal frost in the passage of the seasons.

For the beginning to age in a planet means not decrep

itude in its inhabitants but the very maturing of this

its fruit. Evolution of mind in its denizens continues
A DEPARTURE-POINT 17

long after desolation in their habitat has set in.

Indeed, advance in brain-power seriously develops

only when material conditions cease to be bodily pro

pitious and the loss of corporeal facilities renders its

acquisition necessary to life.

The resemblance, distant but distinctive, of the cli

matic conditions necessary on earth for the best scan

ning of Mars with those which prove to be actually exist

ent on that other world has a bearing on the subject

worth considerable attention. It helps directly to an

understanding and interpretation of the Martian state

of things. Though partial only, the features and traits

of our arid zones are sufficiently like what prevails on

Mars to make them in some sort exponent of physical

conditions and action there. Much that is hard of

appreciation in a low, humid land shows itself an every

day possibility in a high and dry one. The terrible

necessity of water to all forms of life, animal or vegetal,

so that in the simple thought of the aborigines rain is

the only god worth great propitiation upon the due

observance of which everything depends, brings to one

a deeper realization of what is really vital and what but

accessory at best. One begins to conceive what must

be the controlling principle of a world where water is

only with difficulty to be had, and rain unknown.

But in addition to the fundamental importance of

water, the relative irrelevancy of some other conditions
18 MARS AND ITS CANALS CHAI■. II

usually deemed indispensable to organic existence

there find illustration too. On the high plateau of

northern Arizona and on the still higher volcanic cones

that rise from them as a base into now disintegrating

peaks, the thin cold air proves no bar to life. To the

fauna there air is a very secondary consideration to

water, and because the latter is scarce in the lowlands

and more abundant higher up, animals ascend after it,

making their home at unusual elevations with no dis

comfort to themselves. Deer range to heights where

the barometric pressure is but three fifths that of their

generic habitat. Bear do the like, the brown bear of

northern American sea-level being here met with two

miles above it. Nor is either animal a depauperate

form. Man himself contrives to live in comfort and

propagate his kind where at first he finds it hard to

breathe. Nor are these valiant exceptions; as Merriam has ably shown in his account of the San Francisco

peak region for the Smithsonian Institution —a most in

teresting report, by the way — the other animals are

equally adaptive to the zones of more northern lati

tudes on the American continent, zones paralleled in

their flora and fauna by the zones of altitude up this

peak. All which shows that paucity of air is nothing

like the barrier to life we ordinarily suppose and is not

for an instant to be compared with dearth of water.

If in a comparatively short time an animal or plant
 

CHAP. II A DEPARTURE-POINT lit

accustomed to thirty inches of barometric pressure can

contrive to subsist sensibly unchanged at eighteen, it

would be rash to set limits to what time may not do.

And this the more for another instructive fact discov

ered in this region by Merriam : that the existence of

a species was determined not by the mean tempera

ture of its habitat but by the maximum temperature

during the time of procreation. A short warm season

in summer alone decides whether the species shall

survive and flourish; that it has afterward to hiber

nate for six months at a time docs not in the least

negative the result.

That the point of departure should thus prove of

twofold importance, speeding the observer on his

journey and furnishing him with a vade mecum on

arrival, is as curious as opportune. Without such

furtherance, to the bodily eye on the one hand and

the mind's eye on the other, the voyage were less con

clusive in advent and less satisfactory in attent.
CHAPTER III

A BIRD'S-EYE VIEW OF PAST MARTIAN DISCOVERY

. XTITH Mars discovery has from the start waited on

" TM apparent disk. To this end every optical ad

vance has contributed from the time of Galileo's operaglass to the present day. For apparent distance stands

determined by the size of the eye. But although it

is the telescopic eye that has increased, not the distance

that has diminished, the effect has been kin to being

carried nearer the planet and so to a scanning of its disk

with constantly increasing particularity. Mankind has

to all intents and purposes been journeying Marsward

through the years. Any historic account of the planet,

therefore, becomes a chronicle of seeming bodily ap

proach.

Perhaps no vivider way of making this evident and

at the same time no better preface to the present work

could be devised than by putting before the eye in

orderly succession the maps made of Mars by the lead

ing areographers of their day, since the planet first

began to be charted sixty-five years ago. The pro

cedure is as much as possible like standing at the tele

scope and seeing the phenomena steadily disclose.

 

20
..in VIEW OF PAST MARTIAN DISCOVERY 21

Seen thus in order the facts speak for themselves.

They show that from first to last no doubt concerning

what was seen existed in the minds of those competent

to judge by systematic study of the planet at first hand,

and furthermore, from their mutual corroboration, that

this confidence was well placed. For, far from there

being any conflict of authorities in the case, those en

titled to an opinion in the matter prove singularly at

one.

Beginning with Maedler in 1840 the gallery of such

portraitures of the planet comprises those by Kaiser,

Green and Schiaparelli, continued since Schiaparelli's

time by the earlier ones of the present writer. To

this list has been added one by Flammarion, which

though not solely from his own work gives so just a

representation of what was known at the date, 1876, as

to merit inclusion. The remarkable drawings of Dawes

and the excellent ones of Lockyer in 1862-1864 were

never combined into maps by the observers, and though

the former's were so synthesized by Proctor in 1867,

the result was conformed to what Proctor thought ought

to be and so is not really a transcript of the drawings

themselves.

Each of the maps presented marked in its day the

point areography had reached; and each tells its own

story better than any amount of text. They are

all made upon Mercator's projection and omit in
MARS AND ITS CANALS CHAP. Ill

consequence the circumpolar regions. The later ones

give, too, only so much of the surface as was shown at

the opposition they record, for Mars, being tipped now

one way, now another, regards the earth differently ac

cording to its orbital position. In comparing them,

therefore, the equator must be taken for medial line.

Mercator's projection has been the customary one for

portraying Mars except for such oppositions as chiefly

disclose the arctic pole. And this, too, with a certain

poetic fitness. For it comes by right of priority to

delineation of a new world; seeing that Mercator was

the first to represent in a map the mundane new world

in its entirety, by the rather important addition of

North America to the southern continent already

known, and to give the whole the title America with

'Ame' In looking at the attoptheof maps the mapit isandto 'rica' be remembered at the bottom. that

they are what we should call upside down, south stand

ing at the top and north at the bottom. Inverted they

show because this is the way the telescopic observer al

ways sees the planet. The disk would seem unnatural

to astronomers were it duly righted. Just the same do

men in the southern hemisphere look at our own Earth

topsy-turvy according to our view, the Sun being to

the north of them and the cold to the south. Certain

landmarks distinguishable in all the maps may serve for

specific introduction. The V-shaped marking on the
chap, in VIEW OF PAST MARTIAN DISCOVERY 23

equator pointing to the north is the Syrtis Major, the

first marking ever made out upon the planet and drawn

by the great Huyghens in 1659. The isolated oval

patch in latitude 26° south is the Solis Lacus, the pupil

of the eye of Mars; while the forked bay on the

equator, discovered by Dawes, is the Sabaeus Sinus,

the dividing tongue of which, the Fastigium Aryn,

has been taken for the origin of longitudes on Mars.

Twelve maps go to make the series. They are

as follows: —

I. Map ofMaker Beer and Maedler . . . Date

. 1840

II. " Kaiser . 1864

III. " Flammarion (Resume) . 1876

IV. tt " Green 1877

V. tt " Schiaparelli . 1877

VI. a a tt 1879

VII. tt it a . 1881

VIII. a tt tt . 1884

IX. a " Lowell 1894

X. tt . 1896

XI. ii tt a 1901

XII. ii a tt . 1905

If these maps be carefully compared they will be

found quite remarkably confirmatory each of its prede

cessor. To no one will their inter-resemblance seem

more salient than to draughtsmen themselves. For

none know better how surprisingly, even when two
24 MARS AND ITS CANALS CHAP. Ill

men have the same thing under their very noses to copy,

their two versions will differ. Judgment of position

and of relative size is one cause of variation ; focusing

of the attention on different details another. What

slight discrepancies affect the maps are traceable to

these two human imperfections. Maps IV and V

make a case in point : it was to his new-found canals

that Schiaparelli gave heed to the neglect of a due ton

ing of his map ; while Green, less keen-eyed but more

artistic, missed the delicate canaliform detail to make

a speaking portraiture of the whole.

Amid the remarkable continuity of progression here

shown, in which each map will be seen to be at once a

review and an advance, we may, nevertheless, distin

guish three stages in the perception of the phenomena.

Thus we may mark : —

I. A period of recognition of larger markings

II. A period of detection of canals intersecting

the bright regions or lands ; . . . . 1877-1892

III. A period of detection of canals traversing

the ' seas ' and of oases scattered over

Each period is here represented by four charts; and

each expresses the result of a more minute and intimate

acquaintance with the disk than was possible to the one

that went before. To realize, however, how accurate

only ; 1840-1877

the surface; 1892-1905
chap, 111 VIEW OF PAST MARTIAN DISCOVERY 25

each was according to his lights it is only necessary

to have the seeing grow steadily better some evening

as one observes. He will find himself recapitulating

in his own person the course taken by discovery for

all those who went before, and in the lapse of an hour

live through the observational experience of sixty

years; in much the same way that the embryological

growth of an individual repeats the development his

torically of the race.

Two verses of Ovid, which the poet puts into the

mouth of Pythagoras, outline with something like

prophetic utterance the special discoveries which mark

the three periods apart. Ovid makes Pythagoras say

of the then world : —

Vidi ego, quod fuerat quondam solidissima tellus

Esse fretum; vidi factas ex aequore terras;

— Ovid, Metamorphoses XV, 262.

(Where once was solid ground I've seen a strait;

Lands I've seen made from out the sea.)

True as the verses are of Earth, the poet could not have

penned them otherwise had he meant to record the

course of astronomic detection on Mars. For they

sound like a presentiment of the facts. A surface

thought at first to be part land, part water ; the land

next seen to be seamed with straits ; and lastly the sea

made out to be land. Such is the history of the sub

ject, and words could not have summed it more sue
26 MARS AND ITS CANALS CHAP. Ill

cinctly. "Vidi ego, quod fuerat quondam solidissima

tellus esse frctum " rings like Sehiaparelli's own an

nouncement of the discovery of the 'canals.' Indeed,

I venture to believe he would have made it had he

chanced to recall the verse. So "vidi factas ex

aequore terras" tells what has since been learned of

the character of the seas.

Of the three periods the first was that of the main or

fundamental markings only. It came in with Beer

and Maedler, the inaugurators of areography. That

they planned and executed their survey with but a

four-inch glass shows that there is always room for

genius at the top of any profession and that instruments

are not for everything in its instrumentality. Up to

their day the reality of the planet's features had been

questioned by some people in spite of having been

certainly seen and drawn by Huyghens and others.

Beer and Maedler's labors proved them permanent

facts beyond the possibility of dispute.

The second period was the period of the discovery of

the now famous canals, — a new era in the study of

Mars opened by Schiaparclli in 1877 (Map V). Un

suspicious of what he was to stumble on, he seized the

then favorable opposition to make, as he put it, a

geodetic survey of the planet's surface. He hoped this

undertaking feasible to the accuracy of micrometric

measurement. His hopes did not belie him. He
 

Map H. Kaiser, 1804. (From Flammarion's Mars.)


 

Map IV. Green, 1877. (From Flammarion's Mars.)
chap, in VIEW OF PAST MARTIAN DISCOVERY 27

found that it was possible to measure his positions with

sufficient exactness to make a skeleton map on which

to embody the markings in detail — and thus to give

his map vertebrate support. But in the course of his

work he became aware of hitherto unrecognized liga

ments connecting the seas with one another. Instead

of displaying a broad unity of face the bright areas

appeared to be but groundwork for streaks. The

streaks traversed them in all directions, tesselating the

continents into a tilework of islands. Such mosaic was

not only new, but the fashion of the thing was of a

new order or kind. Straits, however, Schiaparelli con

sidered them and gave them the name canali, or chan

nels. How unfamiliar and seemingly impossible the

new detail was is best evidenced by the prompt and

unanimous disbelief with which it was met.

Unmoved by the universal scepticism which rewarded

what was to prove an epoch-making discovery, Schia

parelli went on, in the judgment of his critics, from bad

to worse — for in 1879 (Map VI) he took up again his

scrutiny of the planet to the detecting of yet more par

ticularity. He re-observed most of his old canals and

discovered half as many more; and as his map shows

he perceived an increased regularity in his lines.

In 1881-1882 (Map VII) he attacked the planet again

and with results yet further out of the common. His

lines were still there with more beside. If they had
28 MARS AND ITS CANALS CHAP. Ill

looked strange before, they now appeared positively

unnatural. Not content with a regularity which

seemed to the sceptics to preclude their being facts, he

must needs see them now in duplicate. To the eyes of

disbelief this was the crowning stroke of factitiousness.

In consequence no end of adverse criticism was

heaped upon his observations by those who could not

see. But curiously enough, — what did not attract

attention, — the blindness of the critics was as much

mental as bodily. For they failed to perceive that

the very unnaturalness which seemed to them to dis

credit his observations really proved their genuineness.

His discoveries were so amazing that any change in

strangeness simply went to confirm the universal scep

ticism and clouded logic. Yet properly viewed, a

pregnant deduction stands forth quite clearly on a

study of the maps.

On comparing maps V, VI and VII an eye duly

directed is struck by a difference in the aspect of the

lines. In his first map the 'canals' are depicted sim

ply as narrow winding streaks, hardly even roughly

regular and by no means such departures from the

plausible as to lie without the communicatory pale.

Indeed, to a modern reader prepared beforehand for

geometric construction they will probably appear no

'canals' at all. Certainly the price of acceptance was

not a large one to pay. But like that of the Sibylline
Map V. Schiaparelli, 1877. (From Sehiaparelli's Memoria.)

 

Map VI. Schiaparelli, 1879. (From Sehiaparelli's Memoria.)


 

Map VII. ScbiaparelU, 1881. (From Schiaparelli's Memoriu.)

 

Map VIII. Schlaparelli, \m. (From Scbiaparelli's Memoria.)
chap, in VIEW OF PAST MARTIAN DISCOVERY 29

Books it increased with putting off. What he offered

the public in 1879 was much more dearly to be bought.

The lines were straighter, narrower, and in every way

less natural than they had seemed two years before.

In 1881-1882 they progressed still more in unaccountability. They had now become regular rule and com

pass lines, as straight, as even, and as precise as any

draughtsman could wish and quite what astronomic

faith did not desire. Having thus donned the char

acter, they nevermore put it off.

Now, this curious evolution in depiction points,

rightly viewed, to an absence of design. It shows that

Schiaparelli started with no preconceived idea on the

subject. On the contrary, it is clear that he shared to

begin with the prevailing hesitancy to accept anything

out of the ordinary. Nor did he overcome his reluc

tance except as by degrees he was compelled. For the

canals did not change their characteristics from one

opposition to another; the eye it was that learned to

distinguish what it saw, and the brain made better

report as it grew familiar with the messages sent it.

In other words, it is patent from these successive maps

that the geometrical character of the 'canals' was

forced upon Schiaparelli by the things themselves,

instead of being, as his critics took for granted, foisted

on them by him. We have since seen the regularity

of the canals so undeniably that we are not now in need
30 MARS AND ITS CANALS

of such inferential support to help us to the truth ; but

too late, as it is, to be of controversial moment the de

duction is none the less of some corroboratory force.

With the third period enters what has been done since

Schiaparelli's time. For that master was obliged,

from failing sight, to close his work with the opposition

of 1890. In 1892 W. H. Pickering at Arequipa was the

chief observer of the planet and made two important

discoveries : one was the detection of small round spots

scattered over the surface of the planet and connected

with the canal system; the other the perception of

what seemed to him more or less irregular lines travers

ing the Mare Erythraeum. Both were notable detec

tions. The first set of phenomena he called lakes,

the second river-systems, sometimes schematically

'canals/ but without committing himself to canaliform

characteristics as his drawings make clear. The same

phenomena were seen at that opposition at the Lick,

by Schaeberle, Barnard and others, and called streaks.

These discoveries took from the maria their supposed

character of seas — a most important event in

knowledge of Mars.

The next advance was the detection at Flagstaff

in 1894 of their canaliform characteristics by my then

assistant Mr. Douglass, who in place of the irregu

lar streaks and river-systems of his predecessors

found the seas to be crossed by lines as regular and
 

Map IX. Lowell, 1894.

 

MapX. Lowell, 1896.


 

Map XII. Lowell, 1905.
chap, in VIEW OF PAST MARXIAN DISCOVERY 31

as regularly connected as the canals in the light

regions. To him they appeared broad and ill

defined, but so habitually did to him the canals in the

light areas, while for directness and uniformity the one

set showed as geometrically perfect as the other. All

the dark maria of the southern hemisphere he found to

be laced with them and that they formed a network

over the dark regions, counterparting that over the

light. Still more significant was the fact that their

points of departure coincided with the points of arrival

of the bright-region canals, so that the two connected

to form in its entirety a single system. After the pub

lication of his results (Lowell Observatory Annals,

Volume I, 1895) Schiaparelli identified some of those

in the Syrtis with what he had himself seen there in

1888 (Memoria, VI, 1899), though his own had not been

sufficiently Of other well additions seen ofto him our knowledge to impress since him asmade canals. by

the writer the present book treats; as also of the

theory they originally suggested to him and which his

later observations have only gone to confirm.
CHAPTER IV

THE POLAR CAPS

A LMOST as soon as magnification gives Mars a

disk that disk shows markings, white spots crown

ing a globe spread with blue-green patches on an orange

ground. The smallest telescope is capable of this faroff revelation ; while with increased power the picture

grows steadily more articulate and full. With a two

and a quarter inch glass the writer saw them thirty-five

years ago.

After the assurance that markings exist the next

thing to arrest attention is that these markings move.

The patches of color first made out by the observer are

shortly found by him to have shifted in place upon the

planet. And this not through mistake on his part but

through method in the phenomena ; for all do it alike.

In orderly rotation the features make their appearance

upon the body's righthand limb (in the telescopic

image), travel across the central meridian of the disk

and vanish over its left.hand border. One follows an

other, each rising, culminating and setting in its turn

under the observer's gaze. A constantly progressing

panorama passes majestically before his sight, new
CHAP. IV THE POLAR CAPS 33

objects replacing the old with a march so steady and

withal so swift that a few minutes will suffice to mark

unmistakably the fact of such procession. But for

all this ceaseless turning under his gaze, after a certain

lapse of time it is evident that the same features are

being shown him over again. With such recognition

of recurrence comes the first advance toward acquaint

ance with the Martian world. For that in all their

journeying their configuration alters not, proves them

permanent in place, part and parcel of the solid surface

of that other globe. This surface, then, lies exposed

to view and by its turning shows itself subject, like

our earth, to the vicissitudes of day and night.

In such self-exposure Mars differs from all the four

great planets, Jupiter, Saturn, Uranus and Neptune.

Features, indeed, are apparent on the first two of these

globes and dimly on the other two as well, but they lack

the stability of the Martian markings. They are forever

exchanging place. In the case of Jupiter what we see is

undoubtedly a cloud-envelop through which occasional

glimpses may possibly be caught of a chaotic nucleus

below. With Saturn it is the same; and the evidence

is that the like is true of Uranus and Neptune. What

goes on under their great cloud canopies we can only sur

mise. With Mars, however, we are not left to imagina

tion in the matter but so far as our means permit can

actually observe what there takes place. Except for
34 MARS AND ITS CANALS CHAP. IV

distance, which, through science, year by year grows

less, it is as if we hovered above the planet in a bal

loon, with its various features spread out to our gaze

below.

Attention shows these areographic features to be on

hand with punctual precision for their traverse of the

disk once every twenty-four hours and thirty-seven

minutes. For over two hundred years this has been

the case, their untiring revolutions having been watched

so well that we know the time they take to the nicety

of a couple of hundredths of a second. We thus become

possessed of a knowledge of the length of the Martian

day and it is not a little interesting to find that it very

closely counterparts in duration our own, being only

one thirty-fifth the longer of the two. We also find

from the course the markings pursue the axis about

which they turn; and just as the period of the rotation

tells us the length of the Martian day so the tilt of the

axis, taken in connection with the form of the orbit,

determines the character of the Martian seasons. Here

again we confront a curious resemblance in the cir

cumstances of the two planets, for the tilt of the equator

to the plane of the orbit is with Mars almost precisely

what it is for the Earth. The more carefully the two are

measured the closer the similitude becomes. Sir William

Herschel made the Martian 28°, Schiaparelli reduced

this to 25°, and later determination by the writer
CHAP. IV THE POLAR CAPS 35

puts it nearer 24°. The latter is the one now adopted

in the British Nautical Almanac for observers of

the planet. This is a very close parallelism indeed ;

so that in general character the Martian seasons

are nearly the counterpart of ours. In length, how

ever, they differ; first because the year of Mars is

almost double the length of the terrestrial one and

secondly because from the greater ellipticity of Mars'

orbit the seasons are more unequal than is the case with

us, some being run through with great haste, others

being lingered on a disproportionate time. It is usual

on the Earth to consider spring as the period from the

vernal equinox, about March 21, to the summer solstice,

about June 20 ; summer as lasting thence to the au

tumnal equinox; autumn from this latter date, about

September 20, to the winter solstice on December 21 ;

and winter from that point on to the next spring

equinox again. On this division our seasons in the

northern hemisphere last respectively : spring, 91 days;

summer, 92 days; autumn, 92 days; and winter, 90

days. On Mars these become, reckoned in our days :

spring, 199 days; summer 183 days; autumn, 147

days; and winter, 158 days. If we had counted them

in Martian days they would have totaled about one

thirty-fifth less in number each.

In its days and seasons, then, Mars is wonderfully

like the Earth ; except for the length of the year we
36 MARS AND ITS CANALS CHAP. IV

should hardly know the difference in reckoning of time

could we some morning wake up there instead of here.

Only in one really unimportant respect should we feel

strange; in months we should find ourselves turned

topsy-turvy. But lunations have nothing to do with

climate nor with the alternation between night and

day; and in these two important respects we should

certainly feel at home.

Though the axis could be determined by the daily

march of any marking and thus the planet's tropic,

temperate and polar regions marked out, the process

is made easier by the presence of white patches cov

ering the planet's poles and known, in consequence,

as the polar caps. It is from measures of the patches

that the position of the Martian poles has actually

been determined. These polar caps are exactly analo

gous in general position to those which bonnet our own

Earth. They reproduce the appearance of the ice and

snow of our arctic and antarctic regions seen from space,

in a very remarkable manner. In truth they are things

of note in more ways than one and would claim prece

dence on many counts. Priority of recognition, how

ever, alone entitles them to premier consideration.

Among the very first of the disk's detail to be made

out by man, they justly demand description first.

With peculiar propriety the polar caps have thus

the pas. Not only do they stand first in order of
CHAP. IV THE POLAR CAPS 37

visibility, but they prove to occupy a like position

logically when it comes to an explanation of the

planet's present physical state. It is not matter of

hazard that the most evident of all the planet's mark

ings should also be the most fundamental, the fountainhead from which everything else flows. It is of the

essence of the planet's condition and furnishes the key

to its comprehension. The steps leading to this con

clusion are as interesting as they are cogent. They

start at the polar caps' visibility. For their size first

riveted man's attention and then attention to them

disclosed that most vital of the characteristics of the.

planet's surface: change.

Just as almost all of the features we note are per

manent in place, showing that they belong to the surface,

so are they all impermanent in character. Change

is the only absolutely unchanging thing except position

about the features the planet presents to view. It

was in the aspect of the polar caps that this important

fact first came to light. Not only did they thus initially

instance a general law, they have turned out to make

it ; for by themselves changing they largely cause

change in all the rest. But for a long time they alone

exemplified its workings. To Sir William ITerschel

we owe the first study of their change in aspect. This

eminent observer noted that their varying size was

subject to a regular rhythmic wax and wane timed to
38 MARS AND ITS CANALS CHAP. IV

the course of the seasons of the planet's year. The

caps increased in the winter of their hemisphere and

decreased in its summer and being situate in opposite

hemispheres they did this alternately with pendulum

like precision. His observations were soon abundantly

confirmed, for the phenomena take place upon a vast

scale and are thus easy of recognition. At their maxi

mum spread the caps cover more than one hundred times

as much ground as when they have shrunk to their

minimum. In the depth of winter they stretch over

much more than the polar zone, coming down to 60°

and even 50° of latitude north or south as the case may

be, thence melting till by midsummer they span only

five or six degrees across.

In this they bear close analogue to the behavior

of our own. Ours would show not otherwise were they

viewed from the impersonal standpoint of space. Very

little telescopic aid suffices to disclose the Martian polar

phenomena in this their more salient characteristics

and convince an observer of their likeness to those of the

earth. Any one may note what is there going on by

successive observations of the planet with a three-inch

glass. Nor is the change by any means slow. A few

days at the proper Martian season, or at most a couple

of weeks, produces conspicuous and conclusive altera

tions in the size of these nightcaps of the planet's

winter sleep. Resembling our own so well they were
CHAP. IV THE POLAR CAPS 39

early surmised to be of like constitution and composed,

therefore, of ice and snow. Plausible on its face, this

view of them was generally adopted and common sense

has held to it ever since. It has encountered, of course,

opposition, partly from very proper conservatism,

but chiefly from that earth-centred philosophy which

has doubted most advances since Galileo's time, and

carbonic acid has been put forward by this school of

sceptics to take its place. We shall critically examine

both objections; the latter first, because a certain

physical fact enables us to dispose of it at once. In

casual appearance there is not much to choose between

the rival candidates of common sense and uncommon

subtlety, water and frozen carbonic acid gas, both being

suitably white and both going and coming with the

temperature. But, upon closer study, in one point of

behavior the two substances act quite unlike, and had

half the ingenuity been expended in testing the theory

as in broaching it this fact had come to light to the

suggestors as it did upon examination to the writer

and had served as a touchstone in the case. At pres

sures of anything like one atmosphere or less carbonic

acid passes at once from the solid to the gaseous state.

Water, on the other hand, lingers in the intermediate

stage of a liquid. Now, as the Martian cap melts it

shows surrounded by a deep blue band which accom

panies it in its retreat, shrinking to keep pace with the
40 MARS AND ITS CANALS CHAP. IT

shrinkage in the cap. This is clearly the product of the

disintegration since it waits so studiously upon it. The

substance composing the cap, then, does not pass in

stantaneously or anything like it from the solid to the

gaseous condition.

This badge of blue ribbon about the melting cap,

therefore, conclusively shows that carbonic acid is

not what we see and leaves us with the only alternative

we know of : water.
CHAPTER V

BEHAVIOR OF THE POLAR CAPS

SSURED by physical properties that our visual

appearances are quite capable of being what they

seem we pass to the phenomena of the cap itself. Like

as are the polar caps of the two planets at first regard,

upon further study very notable differences soon dis

close themselves between the earthly and the Martian

ones; and these serve to give us our initial hint of a

different state of things over there from that with

which we are conversant on Earth.

To begin with, the limits between which they fluc

tuate are out of all proportion greater on Mars. It is

not so much in their maxima that the ice-sheets of the

two planets vary. Our own polar caps are much

larger than we think; indeed, we live in them a good

fraction of the time. Our winter snows are in truth

nothing but part and parcel of the polar cap at that

season. Now, in the northern hemisphere snow covers

the ground at sea-level more or less continuously down

to 50° of latitude. It stretches thus far even on the

western flanks of the continents, while in the middle of

them and on their eastern sides it extends ten degrees

 

11
42 MARS AND ITS CANALS CHAP. V

farther yet during the depth of winter. So that we

have a polar cap which is then ninety degrees across.

In our southern hemisphere it is much the same six

months later, in the corresponding winter of its year.

On Mars at their winter maxima the polar caps extend

over a similar stretch of latitude. They do so, how

ever, unequally. The southern one is considerably the

larger. In 1903, 136 days after the winter solstice,

in the Martian calendar February 27, it came down in

longitude 225° to 44° of latitude and may be taken to

have then measured ninety-three degrees across; in

1905, 121 days after the same solstice, it stretched

in longitude 235° to latitude 42° and 158 days later,

in longitude 221° to latitude 41°; values which, sup

posing it to have been round, imply for it a diameter

on these occasions of ninety-six and ninety-seven

degrees. It was then February 20 and March 10

respectively of the Martian year. These determinations

of its size at the two oppositions agree sufficiently well

considering the great tilt away from us of the south

pole at the time and the horizonward foreshortening

of the edge of the snow. It seems from a consensus

of the measures to have been some five degrees

wider in 1903 than in 1905, which may mean a colder

winter preceding the former date. The cap was still

apparently without a dark contour in both years,

showing that it had not yet begun to melt.
 

South Polai Cap. (Lowell Observatory, 1905.)

chap, v BEHAVIOR OF THE POLAR CAPS 43

Less has been learnt of the northern cap. In 1896-

1897 when it was similarly presented skirting the other

rim of the disk, a gap occurred in the observations corre

sponding to the time by Martian months between Feb

ruary 24 and March 22. On the former date the cap

came down only to latitude 55° in longitude 352°;

on the subsequent one and for several days after the

latitude of the southern limit of the snow was such as

to imply a breadth to it of about eighty degrees. The

cap was now bordered by a dark line, proving that melt

ing had already set in. It cannot, however, at its

maximum have covered much more country than this,

in view of its lesser extent on February 24.

Fair as our knowledge now is of the dimensions of the

Martian polar caps at their maxima, we have much

more accurate information with regard to their minima,

and this, too, was obtained much earlier. That we

should first have known their smallest rather than their

greatest extent with accuracy may appear surprising,

exactly the opposite being our knowledge of our own.

It is not, however, so surprising as it appears, inas

much as it is an inevitable consequence of the planet's

aspect with regard to the sun. When the tilt of the

axis inclines one hemisphere toward the sun, that hemi

sphere's polar cap must melt and dwindle, while at

the same time it is the one best seen, the other being

turned away from the sun and therefore largely
44 MARS AND ITS CANALS CHAP. V

from us as well ; so that even such part of the latter

as is illumined lies low down toward the horizon of

the disk where a slight change of angle means a

great difference in size.

It has thus come about that both the south and the

north polar caps have been repeatedly well seen and

measured at their minimum ; and the measures for

different Martian years agree well with one another.

For the northern cap six degrees in diameter is about

the least value to which it shrinks. The south one

becomes even smaller, being usually not more than five

degrees across, while in 1894 it actually vanished, a

thing unprecedented. Its absence was detected by

Douglass at Flagstaff and shortly after the announce

ment of its disappearance the fact was corroborated

by Barnard at the Lick. The position the cap would

have occupied was at the time better placed for obser

vation in America than in Europe, inasmuch as the

cap is eccentrically situated with regard to the geo

graphic pole and its centre was then well on the side

of the disk presented to us while in Europe it was turned

away. This, together with the fact that it undoubtedly

came and went more than once about this time, ac

counts for its disappearance not having been recog

nized there, haze left by it having apparently been

mistaken for the cap itself.

On Earth the minima are much larger. In the
 

North Polar Cap. (Lowell Observatory, 1905.)

chap, v BEHAVIOR OF THE POLAR CAPS 45

northern hemisphere the line of perpetual snow or

pack-ice in longitude 50° east runs about on the 80°

parallel, including within it the southern end of Franz

Joseph Land. Opposite this, in longitude 120° west,

above the North American continent, it reaches down

lower still to 75°. So that the cap is then from twenty

to thirty degrees in diameter. In the southern hemi

sphere it is even larger. In longitude 170° west the

land was found by Ross to be under perpetual snow in

latitude 72°. Cook had reached in longitude 107°

east an impassable barrier of ice in latitude 70° 23'.

The season was then midsummer, January 30. So that

we are perhaps justified in considering 71° south as

about the average limit of perpetual snow or paleocrystic ice. This would make the southern cap at its

minimum thirty-eight degrees across. Pack-ice with

open spots extends still farther north. The Pagoda in

1845 was stopped by impenetrable pack-ice in south

latitude 68° and the Challenger in 1874 encountered

the pack in latitude 65° on the 19th of February, which

corresponds about to our 19th of August, the time at

which the sea should be most open. The limit of per

petual snow is thus lower in the southern than in the

northern hemisphere. Here again, then, the two

minima differ, but in the reverse way from what they

doFrom on Mars. this we perceive that the variations in size of
40 MARS AND ITS CANALS

the caps are much more striking on Mars than on the

Earth and that these are due chiefly to the difference in

the minima, the maxima not varying greatly.

To explain these interesting diversities of behavior

in the several polar caps we shall have to go back a

little in general physics in order to get a proper take

off. It is a curious concomitant of the law of gravity

that the amount of heat received by a planet in passing

from any point of its path to a point diametrically

opposite is always the same no matter what be the

eccentricity of the orbit. Thus, a planet has as many

calories falling upon it in travelling from its vernal

equinox to its autumnal as from the autumnal to the

vernal again, although the time taken in the one journey

be very different from that of the other. This is due

to the fact that the angle swept over by the radius vec

tor, that is, the imaginary bond between it and the sun,

is at all points proportional to the amount of heat re

ceived; just as it is of the gravity undergone, the two

forces radiating into space as the inverse square of the

distance. Thus the heat received by a point or a

hemisphere, through any orbital angle, is independent

of the eccentricity of the orbit.

But it is not independent of the axial tilt. For the

force of the sun's rays is modified by their obliquity.

The amount of heat received at any point in consequence

of the tilt turns upon the position of the point, and for
chap, v BEHAVIOR OF THE POLAR CAPS 47

any hemisphere taken as a whole it depends upon the

degree to which the pole is tilted to the source of heat.

In consequence of being more squarely presented to its

beams, the hemisphere which is directed toward the

sun and therefore is passing through its summer season

gets far more insolation than that which is at the same

time in the depth of its winter. For a tilt of twentyfour degrees, the present received value for the axis

of Mars, the two hemispheres so circumstanced get

amounts of heat respectively in the proportion of

sixty-three to thirty-seven.

But, though the summer and winter insolation thus

differ, they are the same for each hemisphere in turn.

Consequently the mere amount of heat received cannot

be the cause of any differences detected between the

respective maxima and minima of the two polar

caps. If heat were a substance which could be stored

up instead of being a mode of motion, the effect pro

duced would be in accordance with the quantity ap

plied and the two caps would behave alike. As it is

the total amount has very little to say in the matter.

Not the amount of heat but the manner in which this

heat is made at home is responsible for the difference

we observe. Now, though the total amount is the

same in passing from the vernal to the autumnal equinox

as from the autumnal to the vernal, the time during

which it is received in either case varies from one hemi
48 MARS AND ITS CANALS chap, v

sphere to the other. It is summer in the former while

it is winter in the latter and the difference in the length

of the two seasons due to the eccentricity of the orbit

makes a vast difference in the result. Winter affects

the maxima, summer the minima, attained. Of these

opposite variations presented to us by the two caps,

the maxima, the one most difficult to detect, is the

easiest to explain, for the difference in the maxima

seems to be due to the surpassing length of the antarctic

night.

Owing to the eccentricity of the orbital ellipse pur

sued by Mars and to the present position of the planet's

solstices, the southern hemisphere is farther away from

the sun during its winter and is so for a longer time.

The seasons are in length, for the northern hemisphere :

spring, 199 days; summer, 183 days; autumn, 147

days; and winter, 158 days; while for the southern

hemisphere they are : spring, 147 days; summer, 158

days; autumn, 199 days; and winter, 183 days. The

arctic polar night is thus 305 of our days long; the

antarctic, 382. Thus for 77 more days than happens to

its fellow the southern pole never sees the sun. Now,

since the total sunlight from equinox to equinox is the

same in both hemispheres, its distribution by days must

be different. In the southern hemisphere the same

amount is crowded into a smaller compass in the

proportion of 305 to 382 ; that being that hemisphere's
chap, v BEHAVIOR OF THE POLAR CAPS 49

relative ratio of days. But since during winter the cap

increases, there is a daily excess of accumulation over

dissipation of snow and each twenty-four hours must

on the average add its tithe to the sum total. Since the

northern days are the warmer each adds less than do

the southern ones ; and furthermore there are fewer of

them. On both these scores the amount of the dep

osition about the northern pole should be less than

about the southern one. Consequently, the snowsheet there should be the less extensive and show a

relatively smaller maximum, which explains what we

see.

With the minima the action is otherwise. Inasmuch

as the greater heat received during the daylight hours

by the southern hemisphere is exactly offset by the

shortness of its season, it would seem at first as if there

could be no difference in the total effect upon the two

ice-caps.

But further consideration discloses a couple of factors

which might, and possibly do, come in to qualify the

action and account for the observed effect. One is that

though the total amount of heat received is the same,

the manner of its distribution differs in the two hemi

spheres. In the northern one the time from vernal

to autumnal equinox is 382 days against 305 in the

southern. Consequently, the average daily heat is

then five fourths more intense in the southern hemi
.50 MARS AND ITS CANALS CHAP. V

sphere. Indeed, it is even greater than this and nearer

four thirds, because the melting occurs chiefly in the

spring and in the first two months of summer when the

contrast in length of season between the two hemi

spheres is at its greatest. Now, a few hotter days

might well work more result than many colder ones.

And this would be particularly true of Mars where the

mean temperature is probably none too much above the

freezing-point to start with. Ice consumes so much

caloric in the process of turning into any other state,

laying it by in the form of latent heat before it can

turn into water and then so much more before this

water can be converted into steam that a good deal has

to be expended on it before getting any perceptible

result. Once obtained, however, the heat is retained

with like tenacity. So that the process works to

double effect ! If sufficient heat be received the ice is

first melted, then evaporated and finally formed into

a layer of humid air, the humidity of which keeps it

warm. Dry air is unretentive of heat, moist air the

opposite. And for the melting of the ice-cap to pro

ceed most effectively the temperature that laps it about

must be as high as possible and kept so as continuously

as may be. If between days it be allowed to fall too

low at night much caloric must needs be wasted in

simply raising the ice again to the melting-point. This

a blanket of warm air tends to prevent, and this again
BEHAVIOR OF THE POLAR CAPS 51

is brought about by a few hot days rather than by

many colder ones. It is not all the heat received that

becomes effective but the surplus heat above a certain

point. The gain in continuity of action thus brought

about is somewhat like that exhibited between the

running of an express and an accommodation train.

To reach its destination in a given time the former

requires far less power because it does not have to get

up speed again after each arrest. Thus the whole effect

in melting the snow would be greater upon that hemi

sphere The greater whos summer swing inhappens size of theto becapthemostmoreexposed intense.to

the effects of the eccentricity is, then, the necessary

result of circumstances when the precipitation is not

too great to be nearly carried off by the subsequent

dissipation. This is the state of things on Mars and

the second of the factors above referred to. On the

Earth as we have seen the polar caps are somewhat

larger at their maximum and very much so at their

minimum. Now, this is just what should happen

were the precipitation increased. Suppose, for exam

ple, that the amount of precipitation were to increase

while the amount of summer melting remained the

same, and this would be the case if the vapor in the air

augmented for one cause or another, and the result

of each fresh deposit was locked up in snow. After

a certain point the cap would grow in depth rather than
r,2 MARS AND ITS CANALS CHAP. V

in extension; the winter deposit would be thicker

but the summer evaporation would remain the same.

Now, if this occurred, it is evident that the minimum

size of the cap would increase relatively much faster

than the maximum, and furthermore, that the relative

increase of the minimum in the two caps would be

greatest for that which had seasons of extremes.

The reswlt we see in the case of the Earth. In the arctic

cap, where in consequence of the eccentricity of the

orbit the winter is shorter, the maximum is less than

in the antarctic and this extra amount of precipitation

cannot be wholly done away with in its intenser sum

mer, so that the minimum too is greater there.

We reach, then, this interesting conclusion. We find

that eccentricity of orbit by itself not only causes no

universal glaciation in the hemisphere which we should

incidentally suppose likely to show it, but actually

produces the opposite result, in more than offsetting by

summer proximity what winter distance brings about.

To cause extensive glaciation we must have, in addi

tion to favorable eccentricity, a large precipitation.

With these two factors combined we get an ice age, but

not otherwise. The result has an important bearing

on geologic glacial periods and their explanation.

Once formed, an ice-sheet cools everything about it

and chills the climate of its hemisphere. It is a per

petual storehouse of cold. Mars has no such general
chap, v BEHAVIOR OF THE POLAR CAPS 53

glaciation in either hemisphere, and the absence of it,

which is due to lesser precipitation, together with the

clearness of its skies, accounts for the warmth which

the surface exhibits and which has been found so hard

hitherto to interpret. Could our earth but get rid of

its oceans, we too might have temperate regions

stretching to the poles.
CHAPTER VI

MARTIAN POLAR EXPEDITIONS

'LAR certainexpeditions minds, perhaps exert because an extreme theyattraction combine the on

maximum of hardship with the minimum of head

way. Inconclusiveness certainly enables them to be

constantly renewed, without loss either of purpose or

prestige. The fact that the pole has never been trod

by man constitutes the lodestone to such undertakings ;

and that it continues to defy him only whets his en

deavor the more. Except for the demonstration of the

polar drift-current conceived of and then verified by

Nansen, very little has been added by them to our

knowledge of the globe. Nor is there specific reason to

suppose t hat what they might add would be particularly

vital. Nothing out of the way is suspected of the pole

beyond the simple fact of being so positioned. Yet

for their patent inconclusion they continue to be sent

in sublime superiority to failure.

Martian polar expeditions, as undertaken by the

astronomer, are the antipodes of these pleasingly peril

ous excursions in three important regards, which if

less appealing to the gallery commend themselves to the

 

1
chap, vi MARTIAN POLAR EXPEDITIONS 55

philosopher. They involve comparatively little hard

ship ; they have accomplished what they set out to do ;

and the knowledge they have gleaned has proved funda

mental to an understanding of the present physical

condition of the planet.

The antithesis in pole-pursuing between the two

planets manifests itself at the threshold of the inquiry,

in the relative feasibility with which the phenomena

on Mars may be scanned. For, curiously enough, in

stead of being the pole and its surrounding paleocrystic ice which remains hidden on Mars, it is rather the

extreme extent of its extension and the lowest latitu

dinal deposit of frost which lies shrouded in mystery.

The difficulty there is not to see the pole but to see in

winter the regions from which our own expeditions set

out. And this because the poles are well displayed

to us at times which are neither few nor very far be

tween ; while favorable occasions for marking the edge

of the caps when at their greatest have neither proved

so numerous nor so favorable. The tilt of the planet's

axis when conveniently placed for human observation

has been the cause of the one drawback ; the planet's

meteorological condition in those latitudes at that

season the reason for the other.

What knowledge we have of the size of the caps in

degrees upon the surface of the planet at this their

extreme equatorward extension has been given in the
56 MARS AND ITS CANALS chap, vi

last chapter. Their aspect at the time together with

what that aspect betokens was not there touched upon.

With it, therefore, and the peculiarities it presents to

view we shall begin our account of the caps' annual

history.

When first the hemisphere, the pole of which has for

half a Martian year been turned away from the sun,

begins to emerge from its long hibernation, the snowcap which covers it down even to temperate regions

presents an undelimited expanse of white, the edges

of which merge indistinguishably into the groundwork

color of the regions round about. Of a dull opaque

hue along its border, its contour is not sharp but fades

off in a fleecy fringe without hard and fast line of de

marcation. Such notably was the aspect of the north

temperate zone in 1896 when, tilted as it then was away

from us into a mere northern

horizon of the planet's limb,

it showed prior to the definite

recognition of the north polar

cap in August of that year,

and such too was the look of

the disk's southern edge both

before and after the first cer- South Polar Cap in winter. .

tain detection of the south

ern cap in 1903 and 1905. Each was then in the depth

of winter. For in Martian chronology the season cor

 
chap, vi MARTIAN POLAR EXPEDITIONS 57

responded in each at the time to what we know in our

northern hemisphere as the latter part of February

and the early part of March and the appearance of the

planet's surface in both was not unlike what we know

at the same season in latitude 45°. Indeed, there is

reason to suppose bad weather there then and the

extreme fringe, from the pale tint it exhibited, to have

been cloud rather than snow.

It is quite in keeping with what we know on earth

or can conceive of elsewhere that such aspect should

characterize the cap at or near the attainment of its

greatest development. Whether it were not yet quite

arrived at this turning-point of its career or had but

slightly passed it a vagueness of outline would in either

event proclaim the fact. For were the frost still de

positing, the cap's edge would show indefinite ; and on

the other hand had it just begun to melt, evaporation

would give it an undefined edge before the melting

water had gathered in sufficient quantities to be itself

noticeable.

Its behavior subsequent to recognition bore out the

inference from its aspect when it first appeared. While

for many days prior to its coming unmistakably into

view it was impossible to say whether what was seen

of the southern cap in 1903 and 1905 was cloud or

snow; so even after it had definitely disclosed itself it

continued to play at odds with the observer. Showing
.58 MARS AND ITS CANALS chap, vi

sharp at the edges one day it would appear but hazily

defined the next, thus clearly demonstrating itself to be

at the then unstable acme of its spread. Such a state

of things we are only too familiar with in our own

March weather when after days of sunshine that have

melted off the winter's white and fringed it with rivulets

and awakening grass, a snow-storm falling upon it pow

ders the ground again that was beginning to be bare

and at one stroke extends the domain of the snow while

mystifying the actual limits it may be said to occupy.

The same condition of things, then, is not unknown on

Mars, and to fix the precise date of so wavering a phe

nomenon is not so much matter of difficult observation

as of physical impossibility.

Nor is the southern cap, at this the height of its

winter expansion, confined strictly to its own proper

limits. Faint extensions, now so connected with its

main body as to form part and parcel of it, now so de

tached and dull of tint as to make the observer doubt

ful of the exact relationship, are generally to be seen

attendant on it. Hellas in winter is much given to such

questionable garb, and has in consequence been mis

taken by more than one observer for the cap itself,

appearing as it does well upon the southern limb and

being often the only region to show white. Indeed,

frost-bound as it then is, to consider it the polar cap,

though possibly geographically incorrect, may cli
chap, vi MARTIAN POLAR EXPEDITIONS 59

 

Hellas in winter.

matologically be sustainable. Its northern extremity

extends down to latitude 30°, a pretty low latitude

for frost. Still such equatorward extension is not with

out corroborating parallel.

In 1903, at what was in

Martian dates April 26, the

whole of the region south of

the Solis Lacus and the

Nectar showed white, with a

whiteness which may as well

have been hoarfrost as cloud. Now, the Nectar runs

east and west in latitude 28°. So that in this in

stance, too, it is possible that

arctic conditions knocked at

the very doors of the tropics.

Encroachment of the sort is

equivalent to snow in Cairo

and permanent snow at that ;

not an occasional snow flurry,

but something to linger on

the ground and stay visible

sixty millions of miles away.

Knowledge of either cap in this the midwinter of its

year has been a matter of the most recent oppositions

of the planet. Up to within the last few years our

acquaintance with either cap was chiefly confined to the

 

White south of Nectar anil Solis Uicns.
60 MARS AND ITS CANALS chap, vi

months, — one might almost say the weeks, — imme

diately surrounding the summer solstice of its respec

tive hemisphere. The behavior of the caps during the

rest of their career was largely unknown to us, from

the very disadvantageous positions they occupied at the

times the planet was nearest to the earth. Beginning

with 1894, however, our knowledge of both has been

much extended, by a proportionate extension of the

period covered by the observations. It used to be

thought impracticable to observe the planet far on

either side of opposition; now it is observed from as

much as four months before that event to the same

period after it. The result is a systematic series of ob

servations which in many ways has given unexpected

insight into Martian conditions. One of the benefits

secured has been the lengthening of the period of study

of the cap's career, a pushing of inquiry farther back

into its spring history and a longer lingering with it

in its autumnal rebuilding. Yet up to the very last

opposition a gap in its chronology still remained be

tween February 25 and April 1. The opposition of

1905 has bridged this hiatus and brought us down to

the latter date, at which the melting of the cap begins

in earnest.

From this point, April 1 on, we have abundant evi

dence of the cap's behavior. Its career now for some

time is one long chronicle of contraction. Like Bal
chap, vi MARTIAN POLAR EXPEDITIONS 61

zac's Peau de Chagrin it simply shrinks, giving out of its

virtue in the process. The cap proceeds to dwindle

almost under the observer's eye till, from an enor

mous white counterpane spread over all the polar and

a large part of the temperate zone, its area contracts

to but the veriest nightcap of what it was before.

From seventy degrees across it becomes sixty, then

fifty, then forty, till by the middle of the Martian

May it has become not more than thirty degrees in

diameter. During this time, from the moment the

melting began in good earnest, the retreating white

is girdled by a dark band, of a blue tint, which

keeps pace with the edge of the cap, shrinking as it

shrinks, and diminishing in width as the volume of

the melting decreases.

After the melting has been for some time under way

and the cap has become permanently bordered by its

dark blue band a peculiar phenomenon makes its

appearance in the cap itself. This is its fission into one

or more parts. The process begins by the appearance

of dark rifts which, starting in from the cap's exterior,

penetrate into its heart until at last they cleave it in

two. Rifts have been seen by several observers and in

both caps; and what is most suggestive they always

appear in the same places, year after year. Sometimes

oppositions elapse between their several detections

for they are not the least difficult of detail ; but when
62 MARS AND ITS CANALS CHAP. VI

they are caught, they prove to lie just where they did

before.

The permanency in place of the rifts, a characteristic

true of them all, shows them to be of local habit. Thus

the rift of 1884 and 1897 reappeared again to another

observer in the same position in 1901. They are, there

fore, features of, or directly dependent on, the surface

of the planet. But it will not do from this fact to infer

that they are expressive of depressions there. The

evidence is conclusive that great irregularities of sur

face do not exist on Mais. As we shall see when we

come to consider the orology of the planet it is certain

that elevations there of over two or three thousand feet

in altitude are absent. Differences of temperature, able

to explain a melting of the ice in one locality coincidentally with its retention in an adjacent one, must in

consequence be unknown. And this much more con

clusively than at first appears, for the reason that the

smaller the planet's mass the less rapidly does its

blanket of air thin out in ascent above the surface.

This is in consequence of the greater pull the larger

body exerts and the greater density it imparts to a com

pressible gas like our atmosphere. Gravity acts like

any force producing pressure and by it the envelope of

air is squeezed into a smaller compass. But as this is

done throughout the atmospheric layer it means a

more rapid rarefaction as one leaves the body. The
chap, vi MARTIAN POLAR EXPEDITIONS 63

action is such that the height necessary to reach an

analogic density varies inversely as the gravity of the

mass. In consequence of this, to compass a rela

tive thermometric fall for which a moderate difference

of elevation would suffice on Earth, an immoderate

one must be made on Mars. For gravity there being

but three eighths what it is here, eight thirds the rise

must be made to attain a proportionate lowering of

temperature. This fact renders the above argument

against elevation and depression being the cause of

the phenomenon three times as cogent as it otherwise

would be.

With so gradual a gradient in barometric pressure

there and so low a set of contour lines, altitude must be

a negligible factor in Martian surface meteorologic

phenomena. Both density and temperature can be but.

little affected by such cause, and we must search else

where for explanation of what surface peculiarities

we detect.

. Meanwhile the rifts themselves, from being lines

which penetrate the cap from its periphery in toward

its centre, end by traversing it in its entirety and sepa

rating portions which, becoming outlying subsidiary

patches, themselves proceed to dwindle and eventually

disappear. The rifts usually take their rise from such

broader parts of the cap-encircling blue belt as make

beads upon that cordon and are clearly spots where the
64 MARS AND ITS CANALS chap, vi

product of the melting of the cap is either specially

collected, So far the or produces descriptionits might most visible apply with effect.substantial

accuracy to either cap. Yet the conduct of the two is

in some ways diverse and begins to accentuate itself

from this point on.

From the time that the north polar cap reaches a

diameter of about twenty-five degrees, a singular change

steals over it. From having been up to then of a welldefined outline it now proceeds to grow hazy and

indistinct all along its edge. This change in its char

acter at the same period of its career has been quite

noticeable at each of the three last oppositions, so that

small doubt remains that the

metamorphosis is a regularly

recurrent one in the history

of the cap. Coincident with

the obliteration of its con

tour, its dimensions seem

ingly enlarge. It is as if a

hood had been drawn over

Northern Cap hooded with vapor. the cap Qf ft duU white djf_

ferent from the dazzling brilliance of the cap itself

and covering more ground. Such is probably what

occurs; with vapor for veil. The excessive melting of

the cap produces an extensive evaporation which then

in part condenses to be deposited afresh, in part re

 
chap, vi MARTIAN POLAR EXPEDITIONS 65

mains as a covering, shutting off from our view the

outlines of the cap itself. It would seem that at this

time the cap melts faster than the air can carry it

off. A sort of steaming appears to be going on, taking

place in situ. For it clearly is not wafted away.

The time of its coming too is significant. For the

season is May 15, the height of time for a spring haze

to set in. Then later it dissipates with the same quiet

indefiniteness with which it gathered.

It is some time in Martian June before the spring

haze clears away, and when it does go, only a tiny

polar cap stands revealed be

neath it, from six to eight

degrees across, or from a

tenth to a fifteenth of what

it was when it passed into

its curious spring chrysalis.

The date of emergence va

ries. In 1903 it occurred

early, the haze not being

marked after June 3, though recurring again at inter

vals for a day or so. In 1905 it was later; percep

tibly thin after June 21 it did not certainly clear

away till June 9 and came back again on July 16 and

possibly on the 25th.

These vicissitudes of aspect give us glimpses into a

sweet unreasonableness in Martian weather which

 

Northern Cap unmasked.
66 MARS AND ITS CANALS CHAP. VI

makes it seem more akin to our own. And this on two

counts, diurnal and annual. From day to day at

mospheric conditions shift for purely local cause ;

while, furthermore, successive Martian years are not

alike. In some the season is early; in others late.

So that Mars is no more exempt than are we from the

wantonness of weather.

Clearly disclosed thus reduced to its smallest possible

terms it remains for some months of our days, for six

weeks of its own. During that period it continues prac

tically unchanged, neither increasing nor decreasing

significantly in size, nor altering notably in aspect.

Measures of the drawings of it then make it from five

to eight degrees across and it is possible that it really

fluctuates between narrow limits, though its clear-cut

outline at all times renders the variation difficult to

explain. We are not so near it as we could wish;

for on these occasions even at their best it is over two

hundred times as distant as the moon and the greatest

magnification possible still leaves it a hundred thou

sand miles away.

To the south polar cap a somewhat similar history

attaches, but with a difference. In its case no such

regularly recurrent spring haze has yet been noted.

The melting of this cap would seem to be of a more

orderly nature than its fellow and not to outdo what

can conveniently be carried off.
chap, vi MARTIAN POLAR EXPEDITIONS 67

That an excess of evaporation should not take place

is the more peculiar from the fact that at its maximum

it is the larger of the two and therefore has the greater

quantity of matter to get rid of. Its summer, also,

is shorter than the arctic one, so that it has the less

time to dispose of its accumulations. The only other

respect in which it seems to be differently circum

stanced from its antipodes is in the character of its

surroundings. About it are large blue-green areas

which with intermissions stretch down in places to

within less than ten degrees of the equator; whereas

the other pole is continuously encircled for long dis

tances by practically uninterrupted ochre. The char

acter of the environment seems thus the only thing that

can account for the difference in behavior and this

proves the more plausible when we come to consider

what those two classes of regions respectively repre

sent.

In other ways as well the southern cap is the more

self-contained. The rifts, indeed, break it up into

separate portions and these in part remain as outlying

detachments of the main body, as was notably the

case in 1877 and in 1894, but they hardly have the

permanency and importance of those similarly formed

about the arctic pole. Nothing antarctic for instance

compares with the subsidiary patch of the north

polar regions lying in longitude 206°, which both
68 MARS AND ITS CANALS CHAP. VI

in Schiaparelli's time, and during the late oppo

sitions as well was almost as fixed a feature of the

arctic zone as the cap proper. Not quite so constant,

however, and not so solid-looking a landmark is this

patch for all its extent, which nearly equals the area

of the more legitimate portion. It bears on its face a

more pallid complexion as if it were thinner, and this

is borne out by the fact that it occasionally disappears,

an event which so far at least has never befallen the

northern cap itself.

Less constant the southern one is to its own minimum

than the northern. In some seasons, in most in fact, .

it reaches like the other a more or less definite limit

of diminution which it does not pass. But this is not

always the case. In 1894 it disappeared entirely at

the height of its midsummer. The season was probably

unusually hot then in the southern hemisphere of Mars.

In position the caps have something to say about

physiographic conditions. Both caps at their minima

are then irregular and the centre of the south one is

markedly eccentric to the areographic pole. It lies

some six degrees north along the thirtieth meridian.

The northern one is also probably eccentric, but much

less so, with a divergence not much exceeding a degree

and of doubtful orientation. Not only are both caps

not upon their respective poles but they are not oppo

site each other, the one lying in longitude 30°, the other
chap, vi MARTIAN POLAR EXPEDITIONS 69

in 290°. This speaks, of course, for local action. In

some wise this must depend on the configuration of the

surface, yet so far as markings go there is nothing to

show what the dependence is.

The eccentring of the caps is paralleled by the like

state of things on earth. The pole of cold does not

coincide in either hemisphere with the geographic pole.

On the earth its position is largely determined by the

distribution of the land-masses. Continents are not

such equalizers of heat as oceans because of their con

ductivity on the one hand and their immobility on the

other. In winter they part with their heat more quickly

and convection currents cannot supply the loss. This

accounting for thermal pole eccentricity is inapplicable

to Mars because of the absence there of bodies of water.

And it is significant that the degree the earthly poles

of cold are out much exceeds what is the case on Mars.

Possibly areas of vegetation there replace to some effect

areas of water. It is certainly in favor of this view that

the arctic regions there are more desert than the ant

arctic and that the north pole of cold occupies more

squarely the geographic pole.

Not till 1903 did the actual starting again of either

cap chance to be seen. Nor was this, indeed, a matter

of hazard but of persistent inquiry by observation

prolonged after the planet had got so far away that its

scanning had hitherto been discontinued. Such search
70 MARS AND ITS CANALS chap, vi

beyond the customary limits of observation was essen

tial to success, because of the relation of the axial tilt

to the position of the planet in its orbit. At an oppo

sition well placed for nearness, the tilt is such as largely

to hide the pole and to present the polar regions too

obliquely to view for effective scanning. This is true

both of the arctic and the antarctic regions in turn.

For the Martian axis being inclined somewhat as our

own is to the plane of the planet's orbit, we at times

see well and at times but poorly the arctic or antarctic

zones.

The cap, the starting to form of which was thus

caught, was the arctic one; the date 128 days after

the northern summer solstice, or thereabouts, for as is

perhaps natural the advent of the phenomenon partook

of the wavelike advance of such things familiar on

place simultaneously over large areas. The very first

patch of it, in about longitude 320°, extended at one

 earth, an advance succeeded

by a recession and then fol

lowed by another advance.

So much is proof of local

weather there as here. Hoar

frost was successively de

posited and then melted off.

Deposition of frost. What is significant, the

deposition of the frost took
chap, vi MARTIAN POLAR EXPEDITIONS 71

stroke down to latitude 55°. For it actually crossed

the Pierius somewhat to the south. A second patch

stretched to the east of the cap. Two wings these made

to the kernel of cap itself. Through the wings could

be marked the line of the canal : the Pierius upon the

one side, the Enipeus upon the other. Such visi

bility of the canals through the white stretches proved

the white not to be due to cloud suspended between us

and them, but a surface deposit which found no lodg

ment upon the canals themselves. The same avoid

ance of dark markings was evidenced by the showing

of the dark rim round the cap's kernel. Now, if the

deposit were indeed hoarfrost, this failure to find per

manent foothold on the dark markings is what we should

expect to witness. For whether they were vegetation

or water, equally in either case the frost would melt

from them first. Probably they were both vegetal,

though some doubt might exist about the latter, the

band around the kernel. It was then August 20 in

that hemisphere.

Such deposition over great stretches of country is

perhaps not so surprising as it appears at first sight

when seen from without in its totality. After all,

something not unlike it occurs in our snow-storms when

hundreds of square miles are whitened at once. Fur

thermore, with an atmosphere as thin as Mars seems

to possess the temperature must be perilously near the
72 MARS AND ITS CANALS CHAP. VI

freezing-point in the arctic and subarctic regions at

the close of summer.

Steadily, with intermissions, the white sheet increased

until even the dark border to the cap became obliterate,

the kernel showing at first through the veil like the

ghost of what it had been, and then ceasing to be visible

at all, its delimitations being buried under deeper and

deeper depositions of frost.

The perennial portion of the cap was thus merged

in the new-fallen snow. This marked the on-coming of

first fall of frost. Then the pole passed into its starstrewn arctic night, a polar night of twice the duration

of our own and the circumpolar regions entered upon

their long hibernation of ten of our months.

 

First northern snow.

the arctic winter in full force

and happened even before

the polar sun had wholly set.

For the pole did not enter

into the shadow till two of

our months later, the au

tumnal equinox occurring

183 days after the summer

solstice or 55 days after the
CHAPTER VII

WHITE SPOTS

J~N addition to the polar caps proper and to the

subsidiary polar patches that often in late sum

mer flank them round about, other white spots may

from time to time be seen upon the disk. In appear

ance these differ in no respect, so far as observed,

from the arctic subsidiary snow-fields. Of the same

pure argent, they sparkle on occasion in like manner

with the sheen of ice. Equally with the polar caps

they remain permanent in place during the period of

their visibility and are themselves long-lived. Though

by no means perpetual their duration is reckoned by

weeks and even months, and they recur with more or

less persistency at successive Martian years. That,

when seen, they show in particular positions apparently

unaffected by diurnal change precludes their being

clouds, and this fact taken in connection with the

character of their habitat is the puzzling point about

them. For they affect chiefly the north tropic belt.

They, or at least their nuclei, are small, about two or

three degrees in diameter, and are not particularly

easy of detection as a rule, though certain larger ones

73
74 MARS AND ITS CANALS CHAP. VII

are at times conspicuous. Chromatic, rather than

formal, definition is necessary to their bringing out, as

is witnessed by the superb colors the disk presents at

the times when they are best seen. It is then that

Mars puts on the look of a fire-opal.

The first such spot to be noticed was one which

Schiaparelli detected in 1879, at the second opposition

in which he studied the planet. He called it the Nix

Olympica, showing that he recognized in it a cousinship to the polar snows. Yet it lay in latitude 20°

north, longitude 1 131°, in the midst of the ochre

stretches of that part of the disk. It was a small

roundish white speck of not more than two thirds the

diameter of the polar cap. Reseen by him in 1881,

it failed to appear at subsequent oppositions and was

not caught again until 1888. Then once more it van

ished, not to be detected anew till many years after

at Flagstaff, coming out rather surprisingly in 1903.

It showed, however, in the same place as before;

so that its position but not its existence is permanent.

A similar but smaller patch was apparent to Schia

parelli at the same opposition of 1879. This one which

1 Martian longitudes are now reckoned from the Fastigium Aryn,

the mythologic cupola of the world, a spot easy of recognition be

cause making the tongue in the jaws of the Sabaeus Sinus. It further

commends itself because of lying within a degree of the equator. The

longitudes are reckoned thence westward all the way round, or

to 360°.
CHAP. VII WHITE SPOTS T5

he styled the Nix Atlantica lay between the ' Thoth

and the Syrtis Major. It was about half the size of the

Nix Olympica and has never since been seen, though

it should have been had it continued to be what it then

was.

On the other hand, phenomena of the sort undetected

of Schiaparelli have been remarked at Flagstaff. On

May 18, 1901, I was sud

denly struck by the singular

whiteness of the southeast

corner of Elysium where

that region bordered the

Trivium. Elysium has a

way of being bright but not

with such startling intensity

as this spot presented nor

in so restricted an area as was here the case. The

spot was so much whiter than anything I had ever

previously seen outside the polar caps that it arrested

my attention at once. And this the more that I had

observed this same part of the planet the day before

and perceived nothing out of the ordinary. Once

detected, however, the spot continued visible. The

next day it was there with equal conspicuousness, and

now thrust an arm across the Cerberus, entirely ob

literating the canal for the space of several degrees.

In this salience it remained day after day till the

 

White in Elysium.
76 MARS AND ITS CANALS chap, vii

region passed from sight, to reappear with it six

weeks later when the region again rounded into view.

The hour of the Martian day seemed to make no

difference in its visibility. It was seen from early

morning till Martian afternoon, as late as the phase

permitted. Clearly there was nothing diurnal about

its revealing, and it lasted for at least three months

and a half, until the planet got so far away that

observations were discontinued.

It was to all appearances and intents snow. But

"now comes the singular fact about it. It lay within

ten degrees of the equator and showed from the end of

June to the latter part of August. To our ideas there

could be no more inopportune place or time for such

an exhibition. For it cannot have been due to a snow

capped peak, as we know for certain that there are no

mountains in this, or in any other, part of the planet.

Besides, it had not appeared in previous Martian

years ; which it infallibly would have done had it been

a peak. Indeed, it baffles explanation beyond any

Martian phenomenon known to me. It seems directly

to contradict every other detail presented by the

disk.

The phenomenon is thus unique in kind; it is not,

however, unique as a specimen of its kind. The eastern

coast of Aeria where that region borders the Syrtis

Major is prone to a brilliance of the same sort. It is
CHAP. VII WHITE SPOTS 77

a narrow belt of country that shows thus, nothing but

the coastline itself, but this for a considerable distance

stretching several hundred miles in length. It has

stood out saliently bright now at every opposition

which I have observed, beginning with 1894. Some

times it has been described in the notes as bright

simply, sometimes as white, and once, in 1901, as glis

tening at one point like ice. Yet when upon the termi

nator it has never stood forth as a mountain range

should have done to declare its character.

It has been evident regardless apparently of the Mar

tian season. In 1894 it was bright from October 25

to January 16 (Martian chronology); in 1896, from

December 22 to January 7; in 1901, from July 13 to

the 15th; in 1903, at about the same date and so in

1905. It was whitest during the latter oppositions,

showing that the effect is most marked in its mid

summer. All of the above instances of extra-polar

white have been located within the tropics. Examples

of the same thing, however, occur in the north tem

perate zone. Tempe, a region just to the west of the

Mare Acidalium, is exceedingly given to showing a

small white spot close upon the Mare's border in

latitude 50° north. This spot, too, on occasion

glitters as it were with ice. It is also at times very

small. So that whereas much of Tempe is by nature

bright but a small kernel of it is dazzling.
78 MARS AND ITS CANALS CHAP. VII

The list might be easily extended from the record

book. Thus on March 1 and 2, 1903, the disk showed

speckled with ^minute white latitude spots,41°onenorth, in Arcadia one in

these occasions the Martian season was summer;

JulyAs one 9 forapproaches the latter,theJune north21polefor spots the former of like char date.

acter become more numerous. Especially are such

visible north of the Mare Acidalium in the arctic region

thereabout, from 63° to 75° north.

From so widespread a set of instances the only ex

planation which seems to fit the phenomena is that the

mean temperature of Mars is low, not very much above

freezing, and that whatever causes a local fall in the

temperature results in hoar-frost. Such an explanation

accords well with the distance of the planet from the

sun and the thinness of its atmosphere. At the same

time it shows that the mean temperature over the

greater part of the planet the greater part of the time

 

Tharsis near the equator, a

third just north of the

Phoenix Lucus in 10° south,

and a fourth, the Nix

Olympica, and on April 11,

a glittering pin-point starred

like a diamond the centre of

the Pons Hectoris. On both White in the Pons Hectoris.
CHAP. VII WHITE SPOTS 79

is above the freezing-point and that consequently

it is no bar to vegetation of a suitable sort.

That the hoar-frost should be found even at the

equator may perhaps be due to the very thinness of

the air-covering of Mars, which would tend to make

the actual insolation more of a factor than it is with us,

and by the great length of the Martian seasons. In

midsummer the greatest insolation occurs in the arctic

and temperate, not in the tropic regions ; on the other

hand, an atmosphere tends to accumulate heat for the

tropics. With us the latter factor is prepotent; it

would be less effective on Mars. Then again the double

duration of summer would tend to emphasize insolation

as the important factor in the matter. But it is

possible that greater deposition plays a part in the

matter. On earth the rainfall is greatest near the

equator and something of the sort may be true of the

zones of moisture on Mars. That the most striking spots

are found to the west of large dark areas may in this

connection have a meaning inasmuch as, such regions

being vegetation-covered, the air over them is probably

more moisture-laden.

One point about the position of the spots is of

moment: they have all been found in the northern

hemisphere or within ten degrees of it in the southern

equatorial region. This seems at first a question of

hemispheres ; but when we consider that the light areas
80 MARS AND ITS CANALS CHAP. VII

of the surface are chiefly in the boreal hemisphere and in

the south tropic belt, we perceive that it may be rather

the character of the surface there than the particular

hemisphere in the abstract that is decisive in the matter.

Nevertheless, the austral hemisphere is the hemisphere

of extremes, possessing a shorter, hotter summer and

a longer, colder winter than its antipodes. This would

not favor sporadic small depositions of frost in summer

so much as would a climate of a more mean tempera

ture.

From the relative lack of atmospheric covering over

the planet we should expect the nights to prove de

cidedly cool, while the days were fairly warm. Of this

we have perhaps evidence in a singular aspect shown

by the Mare Acidalium in June, 1903. The account

of it in the Annals reads thus: "On May 22 an inter

esting and curious phenomenon presented itself. On

that day, so soon as the Mare Acidalium had well

rounded the terminator on to the disk, at X352°, the

whole of its central part showed white, the edges of

the marking alone remaining as a shell to this brilliant

core. So striking was the effect that beside appear

ing in the drawing it found echo in the notes. The

next day no mention is made of it, and a drawing

made under X20° shows the Mare as usual and the

bright spot in Tempe in its customary place. Neither

was anything of the sort noticed on the 24th and 25th.
CHAP. VII WHITE SPOTS SI

But on the 26th, the day of the projection (upon the

terminator), the effect of the 23d reappeared, the longi

tude of the centre being 332°. Fortunately on that

day a further drawing was secured which enabled its

subsequent behavior to be followed. Made three hours

later than the other, the longitude of the centre being

13°, this drawing shows the Mare well on the disk, its

whole area as dark as usual and with Tempe bright to

the right of it toward the terminator. The terminator

in question was the sunrise one, and we are offered two

suppositions in explanation of the phenomenon : either

the white was due to a morning deposition of hoar-frost

which dissipated as the sun got up, or obliquity ren

dered some superficial deposit visible which more verti

cal vision hid. That the former inference is the more

probable seems hinted at by the simultaneous appear

ance from the 19th to the 26th of other areas of white

between the Mare and the pole. May 26 was 88 days

after the northern summer solstice, and corresponded

to InJulythis31connection on the earth." mentionAnnals, may pertinently Volume III,be§564. made

of Schiaparelli's repeated observation of regions that

whiten with obliquity, a proclivity to which he par

ticularly noticed Hellas and certain 'islands' in the

Mare Erythraeum to be prone. Here as with the Mare

Acidalium we certainly seem to be envisaging cases of

matutinal frost melted by midday under the sun's rays.
CHAPTER VIII

CLIMATE AND WEATHER

JN gazing at the successive phases presented by the

polar caps as their annual history unrolls itself to

view, beginning with vast white cloaks that in winter

hide so effectively the planet's shoulders, to little round

knobs that in summer sit like guardsmen's caps more or

less askew upon the poles, the bodily eye sees only the

glisten of far-off snow. The mind's eye, however,

perceives something more : the conviction they carry

of the presence of an atmosphere surrounding the

planet. Elusive as water vapor is to sight for its

transparency and to spectroscopic determination for

its earthly omnipresence, recognition of its existence

elsewhere by deduction raises such reasoning at once

to a more conspicuous plane than it might otherwise

assume. Especially is this true where the deduction is

itself conclusive, as is here the case. For it depends

on phenomena not its own, but which are in their turn

dependent on it. We are not even beholden to any

knowledge of the substance composing the caps for the

fundamental inference that an atmosphere surrounds

them. Whatever that substance were, the fact that

82
chap, vim CLIMATE AND WEATHER 83

the caps dissipate and reform shows us with absolute

certainty that they pass into the gaseous state, to be

later solidified afresh. This gas constitutes of itself

an atmosphere; while another phenomenon, to wit,

their blue girdles as they melt, affirming their substance

to be snow and ice, enables us to precise the fact that

this gas is water vapor.

From such premise given us by the polar caps we are

able to infer much more by the help of the kinetic

theory of gases. But the speed of parting by a

planet with its gases is conditioned by the mean

speed of each gas. Water vapor will, therefore, go

before nitrogen, oxygen or carbonic acid gas. If,

then, we find it present over the surface of a planet

we are assured of the possibility that the other three

may be there too, and from the similarity of matter

in space strong reason to suspect that they actually

are.

Corroborative evidence of the accuracy of the deduc

tion as to the presence of a Martian air is shown in

several other ways ; in the existence of clouds to begin

with. Rare as they are, these certainly float at times

over parts of the planet, although it is doubtful whether

they can then be seen. Fortunately for assurance we

have other ways of ascertaining their presence than

that of obscuration. Nor is it of account to the argu

ment that they should be few and far between, as they
84 MARS AND ITS CANALS chap, vm

unquestionably are. One single instance of such mediumistic support is enough to support the theory of a

medium; and that instance has been more than once

observed.

Direct evidence of atmosphere is further forthcoming

in the limb-light. This phenomenon might be de

scribed as a brilliant obscuration. It is a circlet of

illumination that swamps the features as they near the

full edge of the disk, the limb of the planet as it is

called. Obliteration of the sort is evident, more or

less markedly, at all times, and is not due to foreshort

ening, as the broadest areas are affected. The fading

out of the detail at the limb suggests nothing so much

as a veil drawn between us and it, lighter in tint than

what it covers. Such a veil can be none other than

air or the haze and cloud that air supports. From its

effect, impartial in place and partial in character,

cloud is inadmissible as a cause and we are left with air

charged with dust or vapor in explanation. Obscura

tion due to it should prove most dense at the limb,

since there the eye has to penetrate a greater depth of

it ; just as on the earth our own air gives azure dimness

to the distance in deepened tinting as the mountains

lie remote.

Another bit of evidence lies in the apparent detec

tion of a twilight arc. In 1894 measures made of the

polar and equatorial diameters of the planet shc^wed
chap, viii CLIMATE AND WEATHER 85

certain systematic residuals left after all known correc

tions had been applied. The only thing which would

account for them was the supposition that a twilight

arc had been unconsciously seen and as unconsciously

measured. In delicate quantities of the sort too great

reliance cannot be put, but if the residuals be not refer

able to other cause they give us not only further evi

dence of an atmosphere, but at the same time our only

hint of that atmosphere's extent. From them it

would seem that the air must be rare, not more than

about four inches of barometric pressure, as we reckon

it, and probably less; a thin, high air more rarefied

than prevails upon our highest mountain tops.

Corroborative of this is the aspect of the planet.

From the general look of the disk a scant covering

of air is inferable. For one of the striking things

about the planet's features is their patent exposure to

our sight. Except in the winter time of its hemisphere

or in the spring after the greatest melting of the polar

cap, nothing seems to stand in our way of an uninter

rupted view of the surface, whether in the arctic, tem

perate, or tropic zones. From the openness of its

expression, however, too much case should not be

made as we really know but little of how an atmosphereenshrouded planet would look. We find no difficulty

in seeing objects a hundred miles away across the sur

face of the earth and yet the thickness of the air strata
86 MARS AND ITS CANALS chap, vm

in such horizontal traversing is many fold what it is

when we look directly up. It is also out of all propor

tion laden with dust and smoke. In the purer regions

of the earth, a clear air imposes but little bar to sight,

and conjures up far things startlingly distinct.

Nevertheless, every evidence points to a thin air

upon Mars : a priori reasoning, indirect deduction and

direct sight. Now, from a thinness of atmosphere it

would follow, other things equal, that the climate was

cold. About this there has been much question, but

less of answering reply. From the distance of the

planet from the sun it is certain less heat is received

by it than falls upon the earth in something like the

ratio of one to two. But that the amount effective

is as the amount received is far from sure. The avail

able heat is much affected by the manner of its recep

tion. A blanket of air acts like the glass of a conser

vatory, letting the light rays in, but hindering the heat

rays out. The light rays falling on the ground or the

air are transformed into heat rays that, finding the re

turn journey less easy, are consequently trapped. All

substances are thus calorifiers, but water vapor is

many times more potent than ordinary air to heatensnaring. A humid air has a hothouse tang to it most

perceptible. Now, what the relative percentage of

water vapor in the Martian atmosphere may be we

do not know.
chap, viii CLIMATE AND WEATHER 87

The thinness of the Martian air has caused it to be

likened to that upon our highest mountain peaks

which are in large part covered with perpetual snow.

But the comparison is not well founded. A peak differs

materially from a plateau in the countenance it gives

to the heat falling upon it. On a plateau each warmed

acre of ground helps the retention of heat by its neigh

bor ; while in addition to being destitute of side support

the higher winds generated about an isolated peak blow

its own caloric away. Still less does any analogy hold

between the two when the plateau is a world-wide one.

From these considerations it is evident glosses are

possible upon the bald idea of a much lower temperature

prevailing on the Martian surface than on the earth's.

Doubtless the theoretic cold has been greatly overdone.

Reversely, recent observations tend to lower the appa

rent temperature disclosed by the features of the disk,

and between the rising of the theoretic and the falling

of the observed we are left with a very reasonable

compromise and reconcilement as the result.

The various look and behavior of the surface of Mars

point to a mean temperature colder than that of the

earth, but above the freezing-point of water; for

regions, at least, outside of the polar caps and during

all but the winter months. Except at certain special

spots, and possibly even there, frost is unknown at all

times within the tropics and except in winter in tern
88 MARS AND ITS CANALS chap, vm

perate latitudes. These anomalous localities, men

tioned in the preceding chapter, may be said to be the

exceptions that prove the rule of general non-glaciation. For if they be snow, they stand witness to its

absence elsewhere upon the disk, and if they are not,

they testify the more emphatically to the same effect.

//Is between different parts of the surface, the tilt

of the Martian axis and the greater length of the Mar

tian seasons, the one the same as, the other the double

of, our own, tend to an accentuation of the heat in the.

temperate and arctic or antarctic zones. The greatest

insolation on earth is not, as we might suppose, at the

equator, but at the parallels of 43. °5 north and south ;

even the poles themselves receiving a quarter as much

heat again on midsummer day as ever falls to the lot of

the line. This broad physical fact is equally true of

Mars, while in the matter of consecutive exposure Mars

in summer outdoes the earth. For the longer the sea

sons, the more nearly does the effective heat approach

the received amount. Thus both on the score of heat

received and of heat husbanded these zones must be

relatively warm. And this shows itself in the look of

the surface. In summer it is clearly warmer within

the polar regions than is the case on earth, to judge by

the effect. In winter the cold is doubtless propor

tionately severe.

For the diurnal range of temperature we have less
chap, viii CLIMATE AND WEATHER 89

data. There is evidence pointing to chilly nights, but

it is meagre, and we are left to fall back on the cold of

our deserts at night for analogic condition of the state

of things over the Martian desert levels after the sun

goes down.

If we are uncertain of the precise character of the

Martian climate, we know on the other hand a good deal

about the Martian weather. A pleasing absence of it

over much of the planet distinguishes Martian conditions

from our own. That we can scan the surface as we do

without practical interruption day in and day out

proves the weather over it to be. permanently fair. In

fact a clear sky, except in winter, and in many places

even then, is not only the rule, but the rule almost

without exceptions. In the early days of Martian

study cases of obscuration were recorded from time

to time by observers, in which portions of the disk were

changed or hidden as if clouds were veiling them from

view. More modern observations fail to support this

deduction, partly by absence of instances, partly by

other explanation of the facts. Certainly the recorded

instances are very rare. Indeed, occasions of the sort

must to any Martians be events, since only one possible

example has presented itself to me during the course

of my observations, extending more or less over eleven

years. Even in this case there was no obliteration,

though a certain whiteness overspread an area near
MARS AND ITS CANALS chap, vm

the equator temporarily. Position seemed to point to

its identity with a cloud which made its appearance

about that time upon the terminator, and lasted for

some thirty-six hours. The cloud, however, showed

evidence of being, not the kind with which we are fa

miliar, but a dust-storm, in keeping, indeed, with the

desert region (Chryse) in which it originated.

With the exception of sporadic disturbance of the sort

the whole surface of the planet outside the immediate

vicinity of the polar caps seems free from cloud or mist

and to lie perpetually unveiled to space. In the neigh

borhood of the caps, however, and especially round

about their edge, a very distinct pearly appearance is

presented during the months at which the cap is at its

maximum, or in other words, in the depth of its winter.

Of a dull white hue and indefinite contour the phenome

non suggests cloud. Where it lies spread no markings

are visible; an absence explicable by obscuration due

an interposed medium, but equally well by seasonal

non-existence of the markings themselves, which from

the general behavior of these markings we know to be

to some extent certainly the fact. Of the regions

where the effect is noticeable, Hellas is the most strik

ing. So conspicuously white during the winter of the

southern hemisphere as to have been often mistaken for

the polar cap, its ghost shows -thus almost regularly every

Martian year. What is as suggestive as it is striking,
chap, vin CLIMATE AND WEATHER 91

the blanching is confined to the solid circle constituting

Hellas and does not extend into the dark regions by

which it is circumscribed. Hellas is as self-contained

when thus powdered as when, in its normal ochre or

abnormal red, it stretches like a broad buckler across

the body of the disk. That the land there lies at a

higher level than its surroundings is pretty certain, but

that the difference can amount to enough to explain its

silveriness as ice is improbable. In latitude Hellas is

distinctly temperate, lying between the parallels of 55°

and 30° ; but on Mars this is no warrant of a like climate.

Again, though close on the south to what constitutes

the polar cap, it does not strictly form part of that cap,

but occupies both in position and in kind a something

intermediary between the frost-bound regions of peri

odic snow and the warmer ones of perpetual sunshine.

It seems to be afflicted with the winter weather of the

north of Europe, and to owe its pearly look at such times

to the same cloud canopy that then distressingly covers

those inclement lands.

Similar in behavior to it is the long chain of socalled islands that, beginning southwest of Thaumasia, runs thence westward even to the eastern edge

of Hellas. These belt the planet in a west-northwesterly

direction by a strip of territory from ten to fifteen de

grees wide, the medial line of which begins at 55°

south and ends in about 40°. They are parted from
92 MARS AND ITS CANALS chap, viii

the main bright areas by blue-green 'seas' of about the

same width as themselves, the Mare Sirenum, the Mare

Cimmerium and Mare Tyrrhenum. These 'seas'

the white that covers the 'islands' never crosses;

though the continent, as we may call it for convenience,

descends at the east to 30° south. Since the 'seas'

are not seas, the cause which might bound the snow,

were they such, cannot be the cause here. Neverthe

less, they have an effect of some sort on the isothermal

lines as is shown not only by latitudinal comparison

with the state of things in Hellas, but with that in

Thaumasia as well. For 30° south is also the limit ap

parently of the white on Thaumasia, where ochre desert

stretches ten degrees farther south still; the region in

its southern part being white-mantled, in its northern

part not. Here again, then, the ochre areas make

exception to what affects the blue-green ones. Clearly

the blue-green regions temper the action of what gives

them wintry cloak. But why they should do this is

not easy to explain on any supposition terrestrial or

marine. Bodies of water tend to foster the formation

of clouds; so, less markedly, do areas of vegetation.

Neither the old ideas, then, nor the new lend themselves

in explanation. It may be that while we here seem

to be envisaging cloud we are in reality looking at hoar

frost. On the other hand, light cloud would show less,

superposed over a dark background, than over an ochre
chap, viii CLIMATE AND WEATHER 93

one ; and this, the simplest of all explanations, may be

the true one. It is facts like these that intrigue us in

the study of the Martian surface by revealing conditions

which render offhand analogy with the earth unsafe.

Indeed, we are more sure of some things which appear

too strange to be true than of others so simple on their

face as to enlist belief. Among the most difficult

and perplexing are meteorological problems like the

above. Here we can only say provisionally that while

cloud best answers to the appearance, frost best fits the

cause. For vegetation might melt frost, yet not dissi

pate cloud. By raising our conception of the mean

temperature the facts can, however, be reconciled and

thisAsisweprobably saw in the solution annual history of the ofdifficulty the polarafter capsall.a

dimness somewhat different affects the northern cap in

May and June. After the melting of the cap is well

under way a haziness sets in along its edge which be

fuddles its outline and effectually hides what is going

on within it. When at last the screen clears away the

cap is found to be reduced to its least dimensions.

Such obstructing sheet looks to be more of the nature

of mist caused by the excessive melting of the cap.

Unfortunately, there are here no patches of blue-green

to test a possible partiality in its behavior over such

tracts ; nor has similar action ever yet been remarked

in the case of the cap of the southern hemisphere.
94 MARS AND ITS CANALS chap, vih

Regular recurrence at the appropriate season of the

planet's year, together with extensive action at the

time, takes this springtide mist to some extent out of

the domain of weather into that of climate. For it

prevails all round the cap and repeats itself in place

as each fresh spring comes on. At least it has done so

for the past three oppositions at which it has been pos

sible to observe well the arctic zones. It is thus both

general in its application and fixed in its behavior.

Nevertheless, it betrays something of the fickleness

which characterizes that more inconstant thing:

weather. For it comes and goes, one thinks for good,

only to find it there again some days later. Not less

captious is the meteorologic action shown in the mak

ing of the new polar cap. When the northern one starts

to form, vast areas of frost are deposited in a single

night. These, however, are not permanent. The

ground thus covered is during the next few days again

partially laid bare. Then a new fall occurs, hiding the

surface a little more completely than before, and the

lost domain is more than regained. By such wave

like advance and recession the tide of frost creeps over

and submerges the arctic regions as the late summer

passes into the autumn. In this alternate coming and

going with succeeding days, we have an unsteadfastness of action most fittingly paralleled by our own

weather. It would seem that local causes there as here
chap, via CLIMATE AND WEATHER 95

are superposed upon the orderly progress of the sea

sons and though at the on-coming of the autumn the

cold is steadily gathering strength, nevertheless warm

days occur now and then to stay its hand, only to be

succeeded in their turn by frosts more biting than be

fore. Even on Mars nothing in the way of weather

is absolutely predicable but impredicability.
CHAPTER IX

MOUNTAINS AND CLOUD

TN all ways but one our scrutiny of the planet is

confined to such view as we might get of it from

the car of a balloon poised above it in space; from

which disadvantage-point we should see the surface

only as a map spread out below us, a matter of but

two dimensions. The exception consists in the obser

vation of what are called projections; irregularities

visible when the disk is gibbous upon that edge of the

planet where the light fades off. Striking phenomena

in themselves they are of particular value for what may

be deduced from them. For by them we are afforded

our only opportunity of gaining knowledge of the sur

face other than in plan and thus of determining be

tween peak, plateau, or plain that to a bird's-eye view

alike lie flattened out to one dead level.

It might at first be thought that our best chance of

noting any elevations or depressions of the Martian

surface lay in catching that surface in profile, by scan

ning the bright edge of it which stands sharp-cut

against the sky and is called the limb. For this is

practically what we do on earth when we mark a
chap, ix MOUNTAINS AND CLOUD 97

mountain against the horizon and measure its height

by triangulation. Unfortunately the method fails in

the case of Mars because of the great distance we are

away. Unless the planet were distinctly more gen

erously equipped than the earth in the matter of

mountains, nothing could be hoped from so forthright

an envisaging. So relatively insignificant to the size

of its globe is the relief of the earth's surface that an

orange skin would seem grossly rough by comparison.

The same proves true for Mars. With the greatest

magnification we can produce, the Martian limb still

appears perfectly smooth.

Luckily, while direct vision is thus impossible, oblique

illumination enables us to get an insight into the

character of the surface we had otherwise been

denied. When mountains or valleys chance to lie

upon the boundary of light and darkness, the rim of

the disk known as the terminator in contradistinction

to the limb where the surface itself comes to an end,

they make their presence evident through an indirect

species of magnification, the elongate effect of oblique

lighting. With a practical instance of it every one

is familiar who has walked by night along a road im

perfectly starred at intervals by electric lights. Startled

between posts by what seemed deep holes and high

furrows he has involuntarily imitated a spavined horse

for fear of stubbing his toes, only to encounter when
f>8 MARS AND ITS CANALS CHAP. IX

his foot fell a surface on contact surprisingly smooth.

The slant illumination by lengthening the shadows

had painfully deceived him into exaggerated inference

of irregularity. What proves disturbing to a way

farer misguided by arc lights is made to do the

eye service when it comes to planetary interpreta

tion. On the boundary of light and shade, those

parts of the surface where it is sunrise or sunset

upon the planet, the sun's rays fall so athwartwise

as to throw enormous shadows from quite small eleva

tions to an eye so placed as to view the surface with

anything approaching perpendicularity. A mountain

mass there will thus proclaim itself by protracted pro

file upon the plain in hundredfold magnification. Simi

larly a peak there will advertise its height by catching

the coming or holding the lingering light at many times

the distance of its own elevation away from the night

side of the planet. Here, if anywhere, then, could

mountains be expected to disclose themselves, and

here, when existent, they have as a matter of fact

been found.

Our own moon offers us the first and easiest example

of such vicariously visible relief. When the moon is

near the quarter, and for three or four days on either

side of that, a keen eye can usually detect one or more

knobs, like warts, projecting from its terminator,

easily distinguished from the limb both by reason of
chap, ix MOUNTAINS AND CLOUD 99

being less bright and of being bounded by a semi-ellipse

instead of a semicircle. If a telescope or even an operaglass be substituted for the eye, it is possible to see

what causes them; the knob resolves itself into the

illuminated rim of a crater separated from the main

body of the visible moon by the seemingly black void of

space. The peak has caught the sunlight, while its

foot and the country between it and the illuminated

surface still lies shrouded in shadow.

From measurement of the distance the sun-tipped

peak seems to stand aloof from the line where the plain

itself is touched by the light, the height of it above that

plain may be calculated. In this way have been found

the heights of the mountains of the moon. Incidentally,

brain outstrips brawn. For pinnacles no Lunarian

could scale, both for their precipitous inaccessibility

and their loftiness, man has measured without so

much as setting foot upon their globe. At each lunar

sunrise and again at lunar sunset these old crater walls

show their crescent coronets tipped the reverse way;

and peaks higher than the Himalayas make gigantic

gnomons of themselves with hands outstretched to grasp

the plains.

In this manner a lunar peak of fifteen thousand feet

shows its presence to the unaided eye. With so much

for starting-point we can calculate how low an eleva

tion could similarly be made out on Mars under a like
100 MARS AND ITS CANALS CHAP. IX

phase illumination. Now, in spheres of different diame

ters the distance out from the terminator for a given

height is as the square root of the diameter. Mars has

about twice the size of the Moon. In consequence, if

we saw the planet at the same distance off as the Moon,

the height of a peak upon it sufficient to cast an equal

shadow or be seen at an equal separation from the

terminator need be but two thirds as high. To see

it thus equidistant a power of 250 or 300 is necessary,

dependent on the opposition. Twice this power may

at times be used, and by the same reasoning this

would reduce the height sufficient to show by four

or to something like 2500 feet. This, then, would be

the theoretic limit of the visible, a limit needing to

be somewhat increased because of the imperfection of

our air.

Having found thus what should be visible on Mars

we turn now to see what is. At once we find ourselves

confronted with a very unlunar state of things. Com

mon upon the face of the Moon, excrescences of the

terminator are rare on Mars. The first ever seen was

detected by a visitor at the Lick Observatory in 1888.

Since then they have been repeatedly noticed both at

the Lick and elsewhere. But although observers are

now on the watch for them, they are not very fre

quently chronicled because not of everyday occurrence.

Much depends upon the opposition; some approaches
chap, ix MOUNTAINS AND CLOUD 101

of the planet proving more prolific of them than others.

How rare they are, however, may be gathered from the

fact that the last three oppositions have disclosed but

one apiece.

An account of the great projection of May 25, 1903,

will give an idea of the extent and interest of the phe

nomenon and will serve to show to what cause we must

attribute all such that have been visible on Mars, for

the behavior of this one was typical of the class.

About half past eight o'clock in the evening of May

26, 1903, Mr. V. M. Slipher, astronomer at Flagstaff,

shortly after taking over the telescope then directed

upon Mars, suddenly noticed a large projection about

halfway up the terminator

of the planet. He at once

sent the out observatory towordsee ofit, the forstaffafactprojec turned an 1 *

tion has for workers on Mars

the like interest that a new

comet possesses for astrono

mers generally. In this Case Projection on terminator.

the phenomenon was specially potent in that it was

the first to be detected that year. Its singularity was

amply seconded by its size. For it was very large, its

extent both in length and height being excessive.

When I first saw it, the projection consisted of an

 
102 MARS AND ITS CANALS chap, ix

oval patch of light, a little to the north of the centre

of the phase ellipse lying parallel to the terminator

but parted from it by darkness to the extent of half

the projection's own width. It made thus not simply

an excrescence but a detached islet of light. It was

easily seen by all those present and was carefully

studied from that time on by Mr. Slipher and me.

Both of us made drawings of it alternately at inter

vals, as well as micrometer measures of its position.

Next to its great size, the most striking feature about

it was its color. This, instead of being white or whitish,

was ochre orange, a hue closely assimilated to the tint

of the subjacent parts of the disk, which was the region

known as Chryse. This distinctive complexion it kept

throughout the period of its apparition. At the same

time Baltia, a region to the north of it and synchro

nously visible close upon the terminator, showed whitish.

The seeing was good enough to disclose the Phison and

Euphrates double, the power a magnification of 310

and the aperture the full aperture of the 24-inch

objective.

From the time it was first seen the detached patch

of light crept in toward the disk, the illuminated body

of the planet. Four minutes after I noted it the dark

space separating it from the nearest point of the termi

nator had sensibly lessened. So it continued, with

some fluctuations intrinsic to the atmospheric diffi
chap, ix MOUNTAINS AND CLOUD 103

culties of observations generally and to the smallness

of the object itself, to become gradually less and less

salient. It lasted for about forty minutes from the

moment it had first appeared to Mr. Slipher and then

passed from sight to leave the edge of the planet smooth

and commonplace again.

The measures made on it showed that it lay when

first seen in longitude 39°.7, latitude 18°. 5 north, and

that its highest point stood seventeen miles above the

surface of the planet. It was three hundred miles

long. These are my own figures, from which Mr.

Slipher's do not substantially differ.

The return of the part of the planet where it had been

seen was eagerly awaited the night after by both

observers, to see if it would bring the projection with it.

For only once a day is the same region of Mars similarly

presented. But in order not to miss the projection,

should it be ahead of time, observations were begun

before it was due. Shortly after they were started,

there appeared higher up the terminator and therefore

farther north than had been the case the night before,

a small projection. It was with difficulty made out

and its position measured. Without careful watching

it must have been missed altogether. As it was, it

differed in every respect from that of the preceding

day. It was not nearly so high, not nearly so large,

and lay in a different place on the planet, being now
104 MARS AND ITS CANALS CHAP. IX

in longitude 31°.7, latitude 25°.5. Either the two,

therefore, were totally different things or the projec

tion had moved in the elapsed interval of time over

seven degrees of latitude and eight degrees of longitude,

a distance of three hundred and ninety miles in twentyfour hours. Where the previous projection had been

nothing showed. On the following night, May 28, no

trace of anything unusual could be seen anywhere.

We are now concerned to inquire to what this series

of appearances could have been due. The first observ

ers of projections on Mars had unhesitatingly attrib

uted them to the same cause that produces projections

on the Moon, to wit, mountains. Such they were

held to be in France and at the Lick. This view, how

ever, was in 1892 disputed by W. H. Pickering who

considered them to be not mountains, but cloud. And

this view was strongly supported by A. E. Douglass

in a discussion of a large number of them observed in

1894 at Flagstaff. The mountain theory of their

generation was finally shown to be untenable and their

ascription to cloud conclusively proved to be the cor

rect solution by the observations of a remarkable

one made in December, 1900, and the careful

study to which by the writer they were subjected.

We shall now explain how this was done and we will

begin by pointing out that the fact that only a single

specimen of the phenomenon was visible at each of the
chap, ix MOUNTAINS AND CLOUD 105

three oppositions of 1900, 1903, and 1905 was itself

conclusive, rightly viewed, of their non-mountainous

character. This conclusion follows at once from the

isolateness of the phenomenon. For a mountain cannot

change its place. Now, the shift in the aspect presented

by the planet's disk from one night to the next is not

sufficient to alter perceptibly the appearance shown

by anything upon its edge on the two occasions. If,

then, a peak stood out upon it one evening, the peak

should again show salient when the region reached the

same position upon the succeeding night. That noth

ing then was seen where something had previously

been visible proved the phenomenon not that of a

mountain peak, since what produced the projection

was clearly not fixed in place and therefore not attached

to the soil. Now the only other thing capable of catch

ing the light before it reached the surface would be

something suspended in the air, that is, a cloud. De

duction, therefore, from the rarity of the phenomenon

alone showed that the projections must be clouds.

Their behavior in detail entirely corroborates this

deduction from their intermittencc. Such was shown

by the action of the projection of December 6, 1900,

as set forth in a paper before the American Philosophi

cal Society and such again by that of the one of May

26, 1903, as we shall now note. To begin with, we

notice that the projection seen on May 26 was not
100 MARS AND ITS CANALS chap, ix

found either in situ or in size on May 27 and had wholly

vanished on May 28, though the seeing was substan

tially the same if not better on the two nights succeed

ing that of its original detection. Hence in its own

instance this projection proved an alibi irreconcilable

with the character of a mountain mass. But it did

more. It not only was not on the second evening

what and where it had been on the first, but the remains

of it visible on the second occasion showed clearly that

it had moved in the meantime. Furthermore it was

disappearing as it went, for it was very much smaller

after the lapse of twenty-four hours. The something

that caused it was not only not attached to the soil,

but was moving and dissipating as it moved. Only

one class of bodies known to us can account for these

metamorphoses and that is: cloud.

But what kind of cloud are we to conceive it to be ?

Our ordinary vapor clouds are whitish and this would

be still more their color could they be looked at from

above. The Martian cloud was not white but tawny,

of the tint exhibited by a cloud of dust. Nor could

this color have very well been lent it by its sunrise

position, for other places equally situated to be tinged

by the hues of that time of day, Baltia to wit, showed

distinctly white. So that we must suppose it to be

what it looked, a something of the soil, not beholden

to atmospheric tinting for its hue; a vast dust-cloud
CHAP. IX MOUNTAINS AND CLOUD 107

traveling slowly over the desert and settling slowly

again to the ground.

Precisely the same general course of drifting disap

pearance was taken by the projection of December 7

and 8, 1900. And this, too, stood an unique appari

tion in the annals of its opposition. Clouds, then, and

not mountains are the explanation of the projections

on Mars, differing thus completely from the lunar ones.
CHAPTER X

THE BLUE-GREEN AREAS

TPVESCENDING now equatorwards from the polar

regions, and their in part paleocrystic, in part

periodic, coating of ice, we come out upon the general

uncovered expanse of the planet which in winter com

prises relatively less surface than on Earth, but in sum

mer relatively more. Forty degrees and eighty-six

degrees may be taken as the mean hiemal and a?stival

limits respectively of the snow on Mars; forty-five

and seventy-five as those of the Earth. Whatever

ground is thus bared of superficial covering on Mars lies

fully exposed to view, thanks to the absence of obscur

ing cloud ; and it is at once evident that the terrrane

is diversified, patches of blue-green alternating with

stretches of reddish ochre. Of the two opaline tints

the reddish ochre predominates, fully five eighths of the

disk being occupied by it.

It was early evident in the study of the surface

of Mars that its ochreish disk was not spotless.

Huyghens in 1659 saw the Syrtis Major. From this

first fruit of areography dates, indeed, the initial recog

nition of the planet's rotation; for on noting that

1(18
chap, x THE BLUE-GREEN AREAS 109

the marking changed its place, he inferred a turning of

the planet upon itself in about twenty-four hours. Thir

teen years later he observed and drew it again and this

time in company with the polar cap. Again, after

eleven more years, he depicted it for the third time, and

now so changed because of the different tilt of the planet

toward the earth that it may be doubted whether Huyghcns himself recognized it for the same. But that

heFrom drew such it correctly small beginning a globe ofdidMarsareography will at onceprogress show.

to the perception of permanent patches of a sombre hue

distributed more or less irregularly over the disk. Im

pressing the observers simply as dark at first, they later

came to be recognized as possessing color, a blue-green,

which contrasted beautifully with the reddish ochre

of the rest of the surface. Cassini, Maraldi, Bianchini,

Herschel, Schroeter, all saw markings which they re

produced. Finally, with Beer and Maedler, came the

first attempt at a complete geography. In and out

through the ochre was traced the blue; commonly in

long Mediterraneans of shade, but here and there in

isolated Caspians of color. With our modern tele

scopic means the dark patches are easily visible, the

very smallest glass sufficing to disclose them. When

thus shown they much resemble in contour the dark

patches on the face of the Moon as seen with the naked

eye. Now these patches were early taken for, lunar
110 MARS AND ITS CANALS CHAP. X

seas and received names in keeping with the conception ;

as the Sea of Serenity, the Sea of Vapors, and so forth.

Following the recognition of a like appearance, like

appellatives were given to the Martian markings ; and

the Mare Sirenum, or Sea of the Sirens, the Mare Cimmerium, and others sufficiently proclaim what was

thought of them at the time they were thus baptized.

Indeed, if a general similarity be any warrant for a

generic name they were not at the time ill-termed.

For, common to all three bodies, the Earth, the Moon,

and the planet Mars, is the figuration of their surfaces

into light areas and dark. In the Martian disk, as in

the lunar one, we seem to be looking at a cartographic

presentation of some strange geography suspended in

the sky; the first generic difference between the two

being that the chart is done in chiaroscuro for the Moon,

in color for Mais. On mundane maps, we know the

dusky washes for oceans; so on the Moon it was only

natural to consider their counterparts as maria; and

on Mars as 'seas.' Nor did the blue-green hue of the

Martian ones detract from the resemblance.

But in something other than color these markings are

alike. In fact, color could hardly be excuse for consider

ing the lunar maria what their name implies, for dis

tinctive tint is lacking in them, even to the naked eye.

It was in form that the likeness lay. Their figures

were such as our own oceans show; and allowing for
chap, x THE BLUE-GREEN AREAS ' 111

a sisterly contrast amid a sisterly resemblance, the

lunar maria or the Martian seas might well have been

of similar origin to those with which our schoolboy

study of atlases had made us familiar. Thus did simi

larity in look suggest similarity in origin, and intuitive

recognition clothe its objects with the same specific

name.

Considerable assumption, however, underlay the

pleasing simplicity of the correlation on other grounds,

consequent not so much upon any lack of astronomic

knowledge as, curiously, upon a dearth of knowledge of

ourselves. We know how other bodies look to us, but we

ignore how we look to them. It is not so easy to see

ourselves as others see us ; for a far view may differ from

a near one, and a matter of inclination greatly alter

the result. Owing both to distance and to tilt we

lack that practical acquaintance with the aspect of our

own oceans viewed from above, necessary to definite

predication of their appearance across interplanetary

space. Our usual idea is that seas show dark, but it is

also quite evident that under some circumstances they

appear the contrary. It all depends upon the position

of the observer and upon the position of the Sun. Their

usual ultramarine may become even as molten brass

from indirect reflection; while on direct mirroring,

they give back the Sun with such scarce perceptible

purloining of splendor as to present a dazzling sheen
112 MARS AND ITS CANALS CHAP. X

not to be gazed upon without regret. Canopied by a

welkin they assume its leaden hue, while at the same

time, their shores, less impressionable to borrowed light

ing, show several tints darker than themselves. Sur

faces so sensitive to illumination hardly admit of more

accusable tint than a chameleon. Nevertheless, we are

probably justified in our conviction that perpendicularly

visaged, they would on the whole outdo in sombreness

land round about them, and so be evident as dusky

patches against a brighter ground.

One phenomenon we might with some confidence look

to see exhibited by them were they oceans, and that is

the reflected image of the Sun visible as a burnished

glare at a calculable point. Specular reflection of the

sort was early suggested in the case of Mars, and physical

ephemerides fpr the planet registered for many years

the precise spot where the starlike image should be

sought. But it was never seen. Yet not till the marine

character of the Martian seas had been otherwise dis

proved was the futile quest for it abandoned. Indeed,

it was a tacit recognition that our knowledge had ad

vanced when this column in the ephemeris was allowed

to lapse.

On this general marine ascription doubt was first

cast in the case of the Moon. So soon as the telescope

came to be pointed at our satellite, it was evident that

the darker washes were not water surfaces at all, but
CHAP. X THE BLUE-GREEN AREAS 113

very palpably plains. Long low ridges of elevation

stood out upon them like prairie swells, which grew in

visible relief according to the slanting character of the

illumination. Cracks or rills, too, appeared near their

edges and craters showed in their very midst. Pat

ently solid they betrayed their constitution not only

by diverse topography but by diversified tint. All

manner of shades of neutral tone mottled their surface,

from seeming porphyry to chalk. Belief perforce de

parted when the telescope thus pricked the bubble,

evaporating as the water itself had done long before.

So much was known before the Mars' markings were

named. Nevertheless, humanity, true to its instincts,

promptly proceeded to commit again the same mistake,

and, cheerfully undeterred by the exposure of its errors

in the case of the Moon, repeated the christening in the

case of Mars. So sure was it of its ground that what

it saw was not ground, that though the particular ap

pellatives of the several seas were constantly altered,

rebaptisms, while changing the personal, kept the generic

name. Dawes' Ocean, for example, later became

l'Ocean Newton and later still the Mare Erythraeum,

but remained set down as much a sea as before. About

thirteen years ago, however, what had befallen the

seas of the Moon, befell those of Mars: the loss of

their character. It was first recognized through a

similar exposure; but the fact was led up to and might
114 MAES AND ITS CANALS chai-. x

have been realized in consequence of quite a different

line of evidence. The initial thing to cast doubt upon

the seas being what they seemed to be was the detection

of change in their aspect. That the detection was not

made much earlier than actually happened shows how

a phenomenon may elude observation if scrutiny be

not persistent, and its results from time to time not

carefully compared. Schiaparelli was the one who

first noticed variation in the look of the seas, and the

discovery was as much due to the assiduity with which

he followed the planet opposition after opposition as to

the keenness with which he scanned it. The noting of

change in the blue-green areas constituted, in fact, one

of the first fruits of systematic study of the planet.

Change in configuration, that is, alteration of area, pre

ceded in recognition alteration of tint. Thus the

Syrtis Major showed larger to him in 1879 'than it had

in 1877. This was natural; difference of degree being

a more delicate matter to perceive than its effect upon

extent. From change of area his perception went on

to change of tone. In his own words, what he noticed

was this: Memoria, VI, 1888, "No less certain is it

that, from one opposition to another, one notices in the

seas, very remarkable alterations of tone. Thus the

regions called Mare Cimmerium, Mare Sirenum, and

Solis Lacus, which during the years 1877 to 1879 could

be numbered among the most sombre on the planet,

f
CHAP. X THE BLUE-GREEN AREAS 115

during the succeeding oppositions became less and less

black, and in 1888 were of a light gray hardly sufficient

to render them visible in the oblique position in which

all three found themselves. ... On the other hand,

at the very same moment, the Mare Acidalium and the

Lacus Hyperboreus showed very dark; the latter in

deed appeared nearly black, although seen as tilted as

the Syrtis and the equatorial bays. The condition of the

regions called seas is therefore not constant: so much

is unquestionable. Perhaps the change produced in

them has to do with the season of the planet's year."

Holding as he did the then prevailing view that the

blue-green regions were bodies of water, he regarded

those of intermediate tint as vast marshes or swamps,

and he accounted for change of hue in them as due to

inundations and occasions of drying up. In conse

quence of losing their water, the seas, he thought,

had in places become so shallow that the bottom

showed through.

Plausible on the surface, this theory breaks down so

soon as it is subjected to quantitative criticism. For

the moment we try to track the water, we detect the

inadequacy of the clew. The enormous areas over

which the phenomenon occurs necessitates the estab

lishing an alibi for all the lost water that has gone.

Drying up on such a scale would mean the removal

of many feet of liquid over hundreds of thousands of
116 MARS AND ITS CANALS CHAP. X

miles in extent. To produce any such change in ap

pearance as we witness, even on the supposition that

these seas were none too deep to start with, would in

volve lowering the level of the water by from five to

twenty feet throughout two thirds of the whole sur

face of the southern hemisphere. This would leave a

heap of waters to be accounted for, bewildering in its

immensity. The myriad tons of it must be disposed of ;

either by drainage into other regions or by being caught

up into the sky.

In this emergency it might seem at first as if the polar

cap of the opposite hemisphere offered itself as a possible

reservoir for the momentarily superfluous fluid. But

such hoped-for outlet to the problem is at once closed

by the simple fact that when the lightening of the dark

regions of the southern hemisphere takes place, the

opposite polar cap has already attained its maximum;

in fact, has already begun to melt. It, therefore, abso

lutely refuses to lend itself to any such service. This

was not known to Schiaparelli's time, the observations

which have established it, by recording more completely

the history of the cap, having since been made. In

deed, it was not known even at the time when the writer,

in 1894, showed the impossibility of the transfer on other

grounds ; to wit, on the fact of no commensurate con

comitant darkening of the surface elsewhere and on the

manifest non-complicity, if not impotency, of the Mar
CHAP. X THE BLUE-GREEN AREAS 117

tian atmosphere in the process. The transference of

the water to other dark patches in the northern hemi

sphere fails of sufficiency of explanation because of

the limited extent of such areas on that side of the

globe; while the air is quite as incapable of carrying

away any such body of liquid, though the whole of it

were at the saturation-point, not to mention that there

exists no sign of the attempt. The reader will find

this reasoning set forth in Mars, published eleven

years ago. He will now note, from what has been said

above about the northern polar cap, that continued

observations since have resulted in opening up another

line of proof which has only strengthened the conclusion

there reached.

The coup de grd.ee, however, to the old belief was

given when the surface of the dark areas was found

to be traversed by perma

nent lines by Pickering

and Douglass. Continued

observation showed these

lines to be unchangeable in

place. Xow permanent

lines cannot exist on bodies

of water, and in conse

quence the idea that what

we looked on there were water surfaces had to be

abandoned.

 

Lines in dark area.
118 MARS AND ITS CANALS CHAP. X

Thus we now know that the markings on both the

Moon and Mars which have been called maria are not

in reality seas. Yet we shall do well still to keep the

old-fashioned sonorous names, Mare Erythraeum, Mare

Sirenum, and their fellows, because it is inconvenient

to change ; while, if we please, we may see in their con

secrated Latin couching the fit embalming in a dead

language of a conception that itself is dead.
CHAPTER XI

VEGETATION

OINCE closer acquaintance takes from the maria

their character of seas, we are led to inquire again

into their constitution. Now, when we set ourselves

to consider to what such appearances could be due we

note something besides sea, which forms a large part

of our earth's surface, and would have very much

what we suppose the latter's aspect from afar to

be, not only in tone, but in tint. This something is

vegetation. Seen from a height and mellowed by

atmospheric distance, great forests lose their green to

become themselves ultramarine.

To dispossess a previous conception is difficult, but

so soon as we have put the idea of seas out of our heads

a vegetal explanation proves to satisfy the phenomena,

even at first glance, better than water surfaces. In

their color, blue-green, the dark areas exactly typify

the distant look of our own forests; whereas we are

not at all sure that seas would. From color alone we

are more justified in deeming them vegetal than marine.

But the moment we go farther into the matter the

more certain we become of being upon the right road.

no
120 MARS AND ITS CANALS CRAP. XI

With increased detection the markings they reveal and

the metamorphoses they undergo, while pointing away

from water, point as directly to vegetation. All the

inexplicabilities which the supposition of water in

volves find instant solution on the theory of vegetal

growth. The non-balancing of the areas of shading

in their shift from one part of the disk to another, no

longer becomes a circumstance impossible to explain,

but a necessary consequence of their new-found char

acter, denoting the time necessary for vegetation to

sprout. The change of hue of vast areas from bluegreen to ochre no longer presupposes the bodily trans

ference of thousands of tons of substance, but the quiet

turning of the leaf under autumnal frosts. Even the

fact that they occupy those regions most fitted by figure

to contain oceans fits in with the same conception.

For that the Martian equivalents of forest and moor

land, tree and grass, should grow now in the lowest

parts of the planet's surface is what might not unrea

sonably be expected from the very fact of their being

low, since; what remained of the water would tend

both on the surface and in the air to drain into them.

For the change in question to be vegetal it must occur

at the proper season of the planet's year. This we must

now consider. We have said that Schiaparelli de

tected change in the blue-green regions and suspected

this change of seasonal affiliation. He inferred this
Of, isdm»o')0 .itjsb nsr'ipM
v.

Mare Erythrapum Martian date. December 30

1

tcrii

t)u< •
 

chap, xi VEGETATION 121

from piecing together the aspects of different seasons

of different years as shown in consecutive Martian oppo

sitions. To mark it actually take place in a single Mar

tian year came later. In 1894, at Flagstaff, the south

ern hemisphere was presented during its late spring

and early summer; it was observed, too, for many of

our months in succession. During this time the planet

was specially well circumstanced for study of the

change in that hemisphere, both by reason of the appositeness of the season and of the unusual size of the

disk. Advantage was token of the double event to

a recording of the consecutive appearances certain

regions underwent, and the contrasted states thus ex

hibited were such as clearly to betoken the action of

seasonal change. What Schiaparelli had thus ably

inferred from diverse portions of different Martian

years was in this case shown occurring in one and the

same semestral cycle.

Usually the change of hue seems essentially one of

tone; the blue-green fades out, getting less and less

pronounced, until in extreme cases only ochre is left

behind. It acts as if the darker color were superim

posed upon the lighter and could be to a greater or less

extent removed. This is what Schiaparelli noted and

what was seen in 1894 at Flagstaff. Three views en

suite of the chain of changes then observed are shown

in Mars, the region known as Hesperia being central
122 MARS AND ITS CANALS CHAP. XI

in each. Comparison of the three discloses a remark

able metamorphosis in that "promontory," a rise into

visibility by a paling of its complexion. Nor is the

contrast confined to it ; changes as salient will be

noticed in the pictures over the other parts of the disk.

There have been instances, however, of a metamor

phosis so much more strange as to deserve exposition

in detail ; one where not tone simply is involved, but'

where a quite new tint has surprisingly appeared.

On April 19, 1903, when, after being hidden for

thirty days, owing to the different rotation periods of the

two planets, the Mare Erythraeum, the largest bluegreen region of the disk and lying in the southern hemi

sphere, rounded again into view, a startling transforma

tion stood revealed in it. Instead of showing bluegreen as usual, and as it had done six weeks before, it

was now of a distinct chocolate-brown. It had been

well seen at its previous presentation, so that no doubt

existed of its then tint. At that time the Martian sea

son corresponded to December 30 in our calendar.

Eighteen Martian days had since elapsed, and it was

now January 16 there. The metamorphosis had taken

place, therefore, shortly after the winter solstice of that

part of the planet. The color change that had super

vened .proved permanent. For the next night the

region showed the same brown hue, and so it contin

ued to appear throughout the days that it was visible.
sur.e[ .Stub ns&wM
Mare Erythraeum Martian date. January 16
 

CHAP. XI VEGETATION 123

Two months passed, and then the chocolate hue had

vanished, — gone as it had come, — and the mare

had resumed its usual tint, except for being some

what pale at the south. It had come to be Febru

ary 21 on Mars. Timed and tabulated, the meta

morphosis through which the mare passed stands

out thus : —

Mare Erythraeum 1903

Mundane

Date • Days refore or after Summer Solstice (Before = —

After = +)

Martian Date Aspect

February 16 -10 December 16 Blue-green

March 20 +22 January 1 Blue-green

April 19 52 January 16 Chocolate

April 22 55 January 18 Chocolate

May 26 89 February 4 Faint chocolate

May 30 93 February 6 Faint chocolate

June 30 123 February 22 Faint blue-green

July 7 130 February 25 Faint blue-green

The culmination of the transformation seems to have

taken place about 60 days after the southern winter

solstice, or in the depth of the Martian winter of that

hemisphere. This is certainly just the time at which

vegetation should be at its deadest.

The northern and southern portions of the mare did

not behave alike in taking on the chocolate tint.

From the notes made about them during the opposition

it appears that the latter was later than the former in
124 MARS AND ITS CANALS chap, xi

undergoing the metamorphosis, as will be seen from

the following depth of the blue green estimated in

percentages shown at different dates, calling the deepest

tone ever exhibited by it unity.

Martian DtCEMBEH January January February February Datb, i16) (1) (17) i5) (24)

% % % % %

Northern 50 50 0 25 50 Southern 50 50 0 0 25

From this table we may place the lowest point of the

blue-green tint as reached about the 22d of Janu

ary for the northern, the 5th of February for the

southern, part. This would indicate that the wave

of returning growth came from the north, not the south ;

an important fact, as we shall see later in studying the

action of the canals.

At the next opposition, in 1905, a recurrence of the

transformation was watched for, and not in vain. It

occurred, however, somewhat later in the Martian sea

son. On December 27 of the planet's current year the

Mare Erythraeum was still as usual, blue-green, nothing

out of the ordinary being remarked in it ; and so it was

on its January 1 7, although the southern edge was darker

than the northern. It looked certainly as if the meta

morphosis were this year to be omitted. But such

was not the case. When the region again came round,

on February 1 of the Martian calendar, there the strange
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CHAT. XI VEGETATION 125

tint was as unmistakable as it had been on its original

occurrence. Not only was the Mare Erythraeum so

colored, but on February 5 (Martian) the northern por

tion of the Mare Cimmerium was observed to be simi

larly affected. In the Mare Erythraeum the anomalous

chocolate hue was confined to a belt between the lati

tudes of 10° and 20° south of the equator; in the Mare

Cimmerium it stretched a little higher, from 10° at the

west to 25° at the east. It is noteworthy that the

southern portion of the latter showed blue at the time

the northern showed brown. Then the metamor

phosis proceeded as shown in the following table: —

Make Erythraeum 1905

MUN DAVE Date Days after winter Solstice oeSoutiiern Hemisphere

Martian, Date Aspect

January March April 46 25 52811 January January December163127 Blue-green Blue-green

Chocolate

April 12 89 February 4 Chocolate

April 30 107 February 13 Faint chocolate

May 8 115 February 17 Faint chocolate

May 12 119 February 19 Faint blue-green

Junely 16115 14953 184 March 6238 Faint blue-green blue-green

Pale bluish green

Here, as in 1903, a chromatic rise and fall is evident ;

the culmination of the change occurring in Martian early

February about ninety days after the winter solstice.

That it was not of long duration is also indicated. If
126 MARS AND ITS CANALS ci.ap. xi

we examine the evidence for the two portions of the

mare separately, the northern and the southern, as in

1903, we find it as follows : —

Martian December January February February March March Date, (27) '16) (2) (16) (7) (23)

% % % % % %

Northern 50 50 0 10 25 30

Southern 50 50 20 20 25 30

Here again a slight retardation in the advent of the

metamorphosis is observable in the southern portion.

There would seem to be a difference in the time of the

change between the two years of fifteen days, 1905

being by that much the later. But with points

of reference themselves thirty days apart, it is

possible the two more nearly coincided than here ap

pears.

Unlike the ochre of the light regions generally, which

suggest desert pure and simple, the chocolate-brown

precisely mimicked the complexion of fallow ground.

When we consider the vegetal-like blue-green that it

replaced, and remember further the time of year at

which it occurred upon both these Martian years, we

can hardly resist the conclusion that it was something

very like fallow field that was there uncovered to our

view.

From the recurrence of the phenomenon on two suc

cessive years, it is likely that it annually takes place.
 
Mate Erythneurn Martian clr.t-. F'tr-arv ?A

( ■ "■ "

V,- .

\ • v

ci—ivc \
 

CHAP. XI VEGETATION 127

That it is seasonal can scarcely be doubted from the

timeliness of its occurrence, and that different portions

of its terrane successively underwent their metamor

phosis shows further that it followed a law peculiar

to the planet, to which we shall be introduced when we

come to consider the phenomena of the canals.

Instances of relative hue in different dark patches

corroboratory of seasonal variation, and therefore of

vegetal constitution, might easily be adduced. Thus,

in 1905 during the summer of the northern hemisphere,

the Mare Acidalium was notably darker than the Mare

Erythraeum to the north of it, which is what the law

of seasonal variation would require, since it was June

in the one, December in the other at the time. But we

need not to add example to example or proof to proof,

for there are no phenomena that contradict it. We

conclude, therefore, that the blue-green areas of Mars

are not seas, but areas of vegetation. Just as reasoning

to a negative result drifts us to the first conclusion, so

reasoning to a positive one lands us at the second.
CHAPTER XII

TERRAQUEOUSNESS AND TERRESTRIALITY

ITH time solid the vanishing ground onofwhich its seasto webuildgetourfor Martian the first

physiography. The change in venue from oceans to

land has produced a complete alteration in our judg

ment of the present state of the planet. It destroys

the analogy which was supposed to exist between Mars

and our earth, and by abolishing the actuality of oceans

there, seems, metaphorically, to put us at first all the

more at sea in our attempt to understand the planet.

But looked at more carefully, it turns out to explain

much that was obscure, and in so doing gives us at once

a wider view of the history of planetary evolution.

The trait concerned is cosmic. Study of the several

planets of our solar system, notably the Earth, Moon,

and Mars, reveals tolerably legibly an interesting phase

of a planet's career, which apparently must happen

to all such bodies, and evidently has happened or is

happening to these three: the transition of its sur

face from a terraqueous to a purely terrestrial con

dition. The terraqueous state is well exhibited by

our own earth at the moment, where lands and

 

128
CHAP. XII TEKKESTRIALITY 129

oceans share the surface between them. The ter

restrial is exemplified by both the Moon and Mars,

on whose surfaces no bodies of water at present exist.

That the one state passes by process of development

into the other I shall now give my reasons for

believing.

In the first place the appearance of the dark markings

both on the Moon and Mars hints that though seas

no longer, they were seas once upon a time. On the

moon, not only does their shape suggest this previous

condition, but the smooth and even look of their sur

faces adds to the cogency of the inference. More im

portant, however, than either of these characteristics,

and confirmatory of both, is the fact that the great

tracts in question seem to lie below the level of the cor

rugated surface, which is thickly strewn with volcanic

cones. Their level and their levelness fay in explana

tion -into one another. The first makes possible the

former presence of water ; the second speaks of its

effect. For their flat character hints that these areas

were held down at the time when the other parts of

the surface were being violently thrown up. That

they can themselves be cooled lava flows, their extent

and position seem enough to negative ; to say nothing

of the fact that they should in that case lie above,

not below, the general level. Something, therefore,

covered them during the moon's eruptive youth and
130 MARS AND ITS CANALS CHAP. XII

disappeared later. Such superincumbence may well

have been water, under which the now great plains lay

then as ocean bottoms. Deep-sea soundings in our

own oceans betray an ocean floor of the same exten

sive sort, diversified as on the moon. To call the

lunar maria seas may not be so complete a misnomer

after all ; but only a resurrecting in epitaph what was

the truth in its day.

Only doubtfully offered here for the Moon, for

Mars the inference seems more sure. Here again the

dark regions not only look as they should had they

had an earlier history, but they, too, seem to lie below

the level of the surface round about. When they pass

over the terminator they invariably show as flattenings upon it, as if a slice of the surface had been pared

off. Such profile in such pass is what ground at a

lower level would present. Undoubtedly a part of the

seeming depression is due to relative absence of irradi

ation consequent upon a more sombre tint, but loss

of light hardly seems capable of the whole effect. In

the case of Mars, then, as with the Moon, a mistaken

inference builded better than it knew, if, indeed, we

should rightly consider an inference to be mistaken

which on half data lands us at the right door.

From the aspects of the dark regions we are led,

then, to regard Mars as having passed through that stage

of existence in which the earth finds itself at the mo
CHAP. XII TEKRESTKIAL1TY 131

ment, the stage at which oceans and seas form a feature

of its landscape and an impediment to subjugation of

its surface in its entirety. What once were ocean beds

have become ocean bottoms devoid of that which

originally filled them.

That the process of parting with a watery envelop

is an inevitable concomitant of the evolution of a planet

from chaos to world, we do not have to go so far afield

as Mars and the Moon for testimony. Scrutiny reveals

as much in the history of our own globe. Two sign

posts of the past, one geologic, the other paleontologic, point unmistakably in this direction. The

geologic guides us the more directly to the goal.

Study of the earth's surface reveals the preponderat

ing encroachment of the land upon the sea since both

began to be, and demonstrates that, except for local

losses, the oceans have been contracting in size from

archaic times. So much is evidenced by the successive

places upon which marine beds have been laid down.

This suggests itself at once as a theoretic probability

to one considering the matter from a cosmic standpoint,

and it is therefore the more interesting and conclusive

that, from an entirely different departure-point, it

should have been one of the pet propositions of the

late Professor Dana, who worked out conclusively the

problem for North America, and published charts

detailing the progressive making of that continent.
132 MARS AND ITS CANALS CHAP. XII

So telling is this reclaiming by nature of land from

the sea that it will be well to follow Dana a little into

detail, as the details show effectively the continuity of

the process acting through aeons of geologic time. At

 

Map of North America at the close of Archaean time, showing approximately the areas of dry land. (From Dana's " Manual of Geology.")

the beginning of the Archaean age, or, in other words,

at the epoch when stratified beds were first laid down,

the earth reached a turning-point in its history.

Erosion, superficial and sub-aerial, then set in to help

restrict the domain of the sea. At this juncture North

America consisted of a sickle of terrane inclosing Hud
CHAP. XII TEKREST1UALITY 133

son's Bay and coming down at its apex to a point not

much removed from where Ottawa now stands, in

about latitude 45° — a Labradorian North America

only. This, the kernel of the future continent, curi

ously symbolized the form that continent was later to

take. For its eastern edge was roughly parallel to the

present Atlantic coastline, although much within and

to the north of it, while its western one was similarly

aligned afar off to the now Pacific slope. Besides this

continent proper, the Appalachian, Rocky Mountain,

Sierra Nevada, and Sierra Madre chains stood out of the

ocean in long, narrow ridges of detached land, outlining

in skeleton the bones of the continent that was to be.

The Black Hills of Dakota and other highlands made

here and there islets in the sea.

Much the same backbone-showing of continents yet

to be filled out was true of Europe, Asia, and South

America. In Europe the northern countries constituted

all that could be called continental land. Most of

Norway, Sweden, Finland, Lapland, existed then, while

the northern half of Scotland, the outer Hebrides, por

tions of Ireland, England, France, and Germany stood

out as detached islands. From this, which is a fair

sample of the proportion of land then to land now over

the other continents so far as they are geologically

known, we turn to consider more in detail the history

of North America.
134 MARS AND ITS CANALS CHAP. XII

By the time the Upper Silurian period came in, the

Appalachian highlands there had been greatly extended

and joined to the Labradorian mainland by continuous

 

North America at the opening of the Upper Silurian. (From Dana's " Manual of Geology.")

territory; otherwise, no important addition had oc

curred, though islands emerged in Ohio, Kentucky, and

Missouri.

At the commencement of the Carbonic era what are

now the Middle states had begun to fill up from the

north, and Newfoundland, from a small island in the

Upper Silurian, had become a great promontory of

Labrador, while the Eastern states region and Nova

Scotia had risen into being. The movements closing
CHAP. XII TERRESTRIALITY 135

Paleozoic time upheaved from low islands the Ap

palachian chain. The earth's crust here crumpled

by contraction upon itself; and the movement ended,

 

Map of North America after the Appalachian Revolution. (From Dana's " Manual of Geology.")

as Dana says, by making dry land of the whole eastern

half of the continent, along substantially its present

lines.

Mesozoic time was the period of the making of the

West. It was an era of deposition and coincident sub

sidence, when the western land had its nose just above

water at one moment to be submerged the next.

Though on the whole this part of the continent was

emerging, the fact was that, synchronously with the
136 MARS AND ITS CANALS chap, xn

sinking of the sea, much of the land from time to time

sank too. The contraction which raised the Appala

chian Mountains at the beginning of the period and that

 

North America in the Cretaceous period. (From Dana's " Manual of Geology.")

of the Rockies at its close overdid the necessities of the

case and caused subsidence elsewhere. The south

eastern portion of the continent suffered most, the West

on the whole materially gaining. In the Triassic and

Jurassic eras the gain was pronounced ; it occurred in

the Cretaceous also, but with much alternation of loss.

Finally, at the close of the Cretaceous, the continent,

except for a prolonged Gulf of Mexico and vast internal

lakes, was substantially complete.

The filling up of these lakes and the reclaiming of
CHAP. XII TERRESTRIALITY 137

land from the Gulf of Mexico constituted the landmaking work of Tertiary times. The extent of the

lakes in the Eocene era is held to show that the general

Map of North America, showing the parts under water in the Tertiary Era; the vertically lined is the Eocene. (From Dana's " Manual of Geology.")

level of the mountain plateau was low and rose later.

So that the gain by the land at this time was greater

than the map allows to appear. By the beginning of

the Quaternary epoch the continents had assumed

their present general area, and since then their internal

features have alone suffered change.

A similar rising from the sea fell to the lot of Europe,

though it has not been detailed with so much care. The

skeleton of that continent was at the beginning of

depositary time much what it is to-day, but a great in

 
138 MARS AND ITS CANALS chap, xh

land sea occupied the centre of it, which, as time went

on, was gradually silted in and evaporated away,

notably during the Upper Silurian period.

From all this it is pretty clear that, side by side with

alternating risings and sinkings of the land, there was

a tolerably steady gain in the contest by which dry

ground dispossessed the sea. We may, of course,

credit this to a general deepening of the ocean bottoms

due to crumpling of the crust, but we may also impute

it to a loss of water, and that the latter is, at least for

a part, in the explanation the condition of the Moon

and Mars makes probable.

Paleontology has the same story of reclamation to

tell as geology, and with as much certainty, though its

evidence is circumstantial instead of direct and speaks

for the growing importance of the land in the globe's

economy since the beginning of depositary time, and

thus inferentially to its increasing extent. Fossil

remains of the plants and creatures that have one after

the other inhabited the earth show that the land has

been steadily rising both in floral and faunal estimation

as a habitat from the earliest ages to the present day.

The record lies imprinted in the strata consecutively

laid down, and except for gaps reads as directly on in

bettering domicile as in evolutionary development.

In Archaean times we find no undisputed evidence

of life either vegetal or animal. But beds of graphite
CHAP. XII TERRESTRIALITY 139

and of limestone point to the possible existence of both.

Even anthracite has been found in Archaean rocks in

Norway and also in Rhode Island. Whether Dawson's

Eozoon Canadense be a rhizopod or a crystal, doctors

of science disagree. Dana, while admitting nothing

specific, deems it antecedently probable that algae

and later microscopic fungi related to bacteria existed

then, living in water well up toward the boiling-point.

Indeed, it is practically certain that invertebrate life

existed, because of its already well-developed character

in the next era. The like antedating is inferable for

the whole record of the rocks. Relatively their history

is undoubtedly fairly accurate, but absolutely it must

be shifted bodily backward into the next preceding era

to correspond with fact not yet unearthed.

In the Lower Cambrian, when first the existence of

life becomes a certainty, that life, so far as known, was

wholly invertebrate and wholly marine; rhizopods

(probably), sponges and corals, echinoderms, worms,

brachiopods, mollusks, and crustaceans grew amid

primitive seaweed and have left their houses in the shape

of shells while perishing themselves. Their tracks

too have thus survived. The trilobites, crustaceans

somewhat resembling our horseshoe crab, were the

lords of the Cambrian seas and marked the point to

which organic evolution had then attained. Their

aquatic character as well as their simple type is shown
140 MARS AND ITS CANALS chap, xn

by their thoracic legs having each a natatory append

age.

In the next era, the Lower Silurian, the fauna and

flora were still marine, although of a higher order than

before, and in the Trenton period, the upper part of the

era, the earliest vertebrates, fishes, come upon the scene :

ganoids and possibly sharks. Nothing terrestrial of

this period has yet with certainty been unearthed in

America. Europe would seem to have either been more

advanced then or better studied since, for there the

first plant higher than a seaweed has been dug up, one

of a fresh-water genus betokening the land; while in

keeping with this the first insect, an hemipter, also has

been disinterred. Both the geography and the life of

the Eopaleozoic period Dana styles "thalassic."

Neopaleozoic time, beginning with the Upper Silu

rian, marked the emergence of the continents, and fol

lowing them the emergence of life from the water on to

this land. In the lower beds of the Upper Silurian in

America we find only the aquatic forms of previous

strata, but in a higher one we come in marshes upon

plants related to the equiseta or horsetails. In

England land plants appear for the first time in these

latest Silurian beds and in the schists of Angers have

been preserved ferns. In both the old world and the

new fossil fishes are found and the oldest terrestrial

species of scorpions. But the great bulk of forms was
chap, xii TERRESTRIALITY 141

still marine; corals, crinoids, brachiopods, trilobites

constituting the principal inhabitants. At this time

the seas were warm, having much the same temperature

between 65° and 80° north as between 30° and 45°;

the prevalence of a general temperate tropicality being

shown by the fact that the common tropical chain

corals lived in latitude 82° north.

In the Devonian era, the Old Red Sandstone, fishes

grew and multiplied, increasing in size apparently

through the era, and in the last period of it reaching

their culminating point. These pelagic vertebrates

much surpassed in structure the terrestrial population

of the time, which was of a low type and consisted of

invertebrates such as myriapods, spiders, scorpions,

and insects; for the land was only making. In the

mid-Devonian, forests of a primitive kind covered such

country as there was, an amphibious land, composed

of jungles and widespread marshes. Tree ferns made

the bulk of the vegetation, but among them grew also

cycads and yews. Mammoth may-flies flitted through

the gloom of these old forests, but no vertebrate as yet

had left the sea.

Following upon the Old Red Sandstone were laid

down the Carbonic strata, and with the Carbonic en

tered upon the scene the advance scouts of an army

of progress evolutionarily impelled to spy out the land

— the first amphibians. They made their debut in the
142 MARS AND ITS CANALS CHAP. XII

Subcarboniferous section of the era, the oldest of the

three periods into which the Carbonic is divided,

crawling out of the sea to return again and leaving but

footprints at first on the sands of time. In the second

period, the Coal-measures proper, they ventured so far

as to leave their skeletons on terra firma, or rather

infirma, while their tracks there show them to have

been now in great numbers. In this manner the an

cestors of the oldest land inhabitants began to struggle

out of the sea. In the Permian, the third and latest

period of paleozoic times, we find their descendants

established in their new habitat, for in it we come upon

the first reptiles. Such possession marks a distinct

step up in function as in fact, for while amphibians

visited dry land, reptiles made it their home. The

getting out of the water had now, in the case of the

more evolved forms, become an accomplished fact.

The reptiles were, indeed, the lowest and most general

ized of their class, Rhynchocephalians, "beak-headed"

species that by their teeth proclaim their marine

origin and their relationship to the great amphibians

that still felt undecided where to stay. Meanwhile,

in Europe dragon-flies, two feet across, possessed the

air; while amphibians there, as here, ancestrally pre

ceded reptiles in occupying the land.

Mesozoic times were, par excellence, the age of mon

sters; for the Triassic (the New Red Sandstone),
CHAP. III TEKRESTRIALITY 143

Jurassic and Cretaceous eras marked the reign of the

reptiles. Great dinosaurs sleep still in the Triassic

strata of the Atlantic border and in the Jurassic of the

Western states, to be unearthed from time to time

and be given mausolea in our museums. Gigantic

they were and very literally possessed the earth. In

Europe they were substantially as in America during

these mesozoic eras, and showed their dominance by

long survival in time as well as world-wide distribution

in space; for they lived all the way from Kansas to

New Zealand and from the Trias to the Upper Cre

taceous. It is supposed by Professor Osborn that many

of them, like the herbivorous brontosaurus, waded in

marshes, not wholly unlike in habit to the modern

hippopotamus. Others were land-stalking carnivores,

like the megalosaurs of a little later date. Of enormous

size, the largest exceeded any animal which has ever

lived, the whales alone excepted; the biggest, the

atlantosaurus and the brontosaurus, reaching a length

of sixty feet. For all their bulk they had scant brains,

just enough to enable them to feed and wallow, prob

ably. It is interesting to note that many of the rep

tiles, the less adventurous, apparently reverted to the

sea. For though the crocodilians existed already in

the Trias, the plesiosaurians did not come in till the

Middle Trias in Europe, and the sea-serpents (mosasaurus) till the Upper Cretaceous.
144 MARS AND ITS CANALS CHAP. XII

Though the dinosaurs dominated life in those days,

higher forms, their descendants, unnoticed were gradu

ally creeping in, eventually to supplant them. For

brain was making its way unobtrusively in the earliest

of the mammals, diminutive creatures at first and of the

lowest type. First appearing in the Trias as some

thing approaching the missing link between reptiles

and mammals, they later developed into monotremes

and marsupials, not rising in differentiation above the

latter order to the end of Mesozoic times. And this

both in the old world and the new. In the Jurassic, too,

flying lizards and the first birds appeared, showing

their pedigree in their teeth.

With Cenozoic times we come upon the first true or

placental mammals with their culmination up to date

in man. In the Eocene they were of a primitive type ;

they were also of a comprehensive one, fitted to cat any

thing. From this they specialized, some evolving and

some on the whole devolving ; the whale, for instance,

taking to the water in the Eocene through the same

degenerate proclivity that had characterized the seasaurians ages before. The earth was growing colder,

though still fairly warm, and with the fall in tempera

ture the higher types of life antithetically rose, evolu

tion gradually fitting them to cope with more advanced

conditions. In this manner did the land supplant the

sea as the essential feature of the earth's surface, first,
chap, xh TERRESTRIALITY 145

in coming into being, and then, by offering conditions

fraught with greater possibilities, as the habitat of the

most advanced forms of life, both plants and animals.

The possibility of advance in evolution was largely

due to the fact that the land did thus supplant the sea.

Spontaneous variation, the as yet unexplained primum mobile in the genesis of species, is probably to be

referred to chemism and is likely later to receive its

solution at the hands of that science. In the meanwhile

it is evident that unless the variation obtain encourage

ment from the environment no advance in type occurs.

Now the land offers to an organism sufficiently evolved

to benefit by it, opportunities the sea does not possess.

First of these, undoubtedly, is the care it enables to be

given to the young. To cast one's brood upon the

waters is not the best method of insuring its bringing up.

There is too much of the uncertainties of wave and cur

rent to make the process a healthy one, and even when

attached to rocks and seaweed, the attachment to a

mother is to be preferred. Without a period of in

fancy, when the young is unable to do for itself, no great

development is possible. In the only striking excep

tion, the case of the whales, dolphins, and porpoises,

size has probably counted for much in the matter, while

the development of the cetaceans is far behind that

of Change the majority of place, of land not mammals. in distance, but in variety, is

i.
146 MARS AND ITS CANALS chap, m

another factor. The sea is same as a habitat, one square

mile of it being much like another, except for gradually

changing temperature. The land, on the other hand,

from its accidented surface, presents all manner of

diversity in the conditions. And the more varied the

conditions to which the organism is exposed, the greater

its own complexity must be to enable it to meet them.

That the terrestrial stage of planetary development

is subsequent to the terraqueous one, and must of

necessity succeed it if the latter ever exist on a body,

follows from the loss of internal heat on the one hand

and from the kinetic theory of gases on the other. To

which of the two to attribute the lion's share in the

business is matter for doubt ; but that both must be

concerned in it we may take for certain.

So long as the internal heat suffices to keep the body

fluid, the liquid itself sees to it that all interstices are

filled. As the heat dissipates, t he body begins to solidify,

starting with the crust. For cosmic purposes it un

doubtedly still remains plastic, but cracks of relatively

small size are both formed and persist. Into these the

surface water seeps. With continued refrigeration the

crust thickens, more cracks are opened and more water

given lodgment within, to the impoverishment of the

seas. The process would continue till the pressure of

the crust itself rendered plastic all that lay below, be

yond which, of course, no fissures could be formed.
CHAP. XII TEKRESTRIALITY 147

How competent to swallow all the seas such earth cuti

cle cracks may be we ignore ; for we cannot be said to

know much of the process. We can only infer that to

a certain extent internal absorption of surface seas

must mark a stage of the evolution by which a star

becomes a world and then an inert mass, one of the

dark bodies of which space is full.

Of the other means we know more. We are certain

that it must take place, though we are in doubt as to

the amount it has already accomplished. This method

of depletion is by the departure of the water in the form

of gas, in consequence of the molecular motions. If we

knew the temperature and the age of Mars and also

the amount of atmosphere originally surrounding it,

we could possibly predicate its state. Reversely, we

can infer something as to age and temperature from

its present condition.
CHAPTER XIII

THE REDDISH-OCHRE TRACTS

"P^OTH for their evidence and their extent the great

ochre stretches of the disk claim attention first.

Largely unchangeable, these show essentially the same

day after day and from the year's beginning to its end.

In hue they range from sand color to a brick red ; some

parts of the planet being given to the one tint, some

to the other. It is to the latter that the fiery tint of

Mars to the naked eye is due. The differences in com

plexion are local and peculiar, both in place and time.

For though saffron best paints the greater part of the

light areas, certain localities present at times a red

like that of our red sandstone. Hellas is one of these

ruddy regions and Aeria another. It is only on occasion

that they thus show, and to what to assign their varia

bility is as yet matter of conjecture. Possibly it is

owing to Martian meteorologic condition; possibly

to something else. But whatever its origin, the change

is not so much contradictory of, as supplementary to,

the general fact of unalterableness, which is after all

the basic trait about them and the keynote to their

condition.

148
chap, mi THE REDDISH-OCHRE TRACTS 149

Land the ochre regions have generally been taken for,

and land they still make good their claim to be con

sidered. For the better they are seen, the greater the

ground for the belief. Indeed, they seem to be noth

ing but ground, or, in other words, deserts. Their

color first points them out for such. The pale salmon

hue, which best reproduces in drawings the general

tint of their surface, is that which our own deserts wear.

The Sahara has this look ; still more it finds its coun

terpart in the far aspect of the Painted Desert of

northern Arizona. To one standing on the summit of

the San Francisco Peaks and gazing off from that iso

lated height upon this other isolation of aridity, the

resemblance of its lambent saffron to the telescopic

tints of the Martian globe is strikingly impressive.

Far forest and still farther desert are transmuted by

distance into mere washes of color, the one robin's-egg

blue, the other roseate ochre, and so bathed, both, in

the flood of sunshine from out a cloudless burnished

sky that their tints rival those of a fire-opal. None

otherwise do the Martian colors stand out upon the

disk at the far end of the journey down the telescope's

tube. Even in its mottlings the one expanse recalls

the other. To the Painted Desert its predominating

tint is given by the new red sandstone of the Trias,

the stratum here exposed; and this shows in all its

pristine nakedness because of the lack of water to clothe
150 MARS AND ITS CANALS chap, xui

it with any but the sparsest growth. Limestones that

crop out beside it are lighter yellow, whitish and steelgray, and seen near give the terrane the look of a

painter's palette. Seen from far they have rather the

tint of sand ; and the one effect, like the other, is Mar

tian in look. And as if to assimilate the two planetary

appearances the more, the thread of blue-green that

attention traces athwart the Painted Desert marks

the line of cottonwoods along the banks of the Little

Colorado River — deserts both, if look be any guarantee

of character, with verdure banding them.

In other ways these earthly deserts offer a parallel

to the Martian. No desert on the Earth is absolutely

devoid of life of some kind, vegetal and animal. The

worst conditioned are not what one is taught in child

hood to believe a desert to be — a vast waste of sand,

with a camel and a palm thrown in to heighten the

sterility. In all Saharas outside of the pages of the

school books some vegetation grows, though it is com

monly not of a kind to boast of, being rather a succes

d'estime, as sagebrush, ca6ti, and the like. But what

is of interest here in the connection is its color. For

it is commonly of a more ochreish tint than usual, in

keeping with its surroundings, a paling out of the green

to something more tawny, indicating a relative reduc

tion of the chlorophyll and an increase of the lipochromes in the tissues of the plant, since the one gives
chap, xiii THE REDDISH-OCHRE TRACTS 151

the green tint to the leaves, the other the yellow. As

this vegetation, poor as it is, has its annual history,

it must alter the look of the desert at times and pro

duce precisely those slight variations in tint observable

on Mars in like circumstance.

The Arizona desert dates from no further back than

early Tertiary times, as the limestone of the Cretaceous

there present shows. Water then stretched where

desert now is, and the limestone beds were laid down in

it. How old the Martian Saharas are we have no means

of knowing. But one thing we may predicate about

both : a desert is not an original, but an acquired, condi

tion of a planet's surface, demonstrably so in the case

of a planet which has had a sedimentary epoch in its

life-history. In the Arizona desert the surface is com

posed of depositary rocks of Mesozoic times, except

where lava streams have flowed down over it since

then. The land, then, was once under water, and

cannot but have been fertile for some time after it

emerged.

But we are not left to inference in the matter, how

ever good that inference may be. A little to the south

of the Painted Desert, in the midst of the barren plateau

of northern Arizona, of which the former makes a part,

stand the remains of a petrified forest. Huge chalced

ony trunks of trees, so savingly transmuted into stone

that their genus is still decipherable, lie scattered here
152 MAKS AND ITS CANALS CHAP. XIII

over the barren ground in waste profusion, one of them

still spanning a canon just as it fell in that, to it, de

structive day of a far prehistoric past. The rock

stratum on which their remains lie is of Triassic and

Cretaceous times and the petrifications show that in

the Cretaceous a stately forest overspread the land.

In those days at least the spot was fertile where now

sparse sagebrush and cacti find a living hard. Not here

alone where the blocks are so conspicuous as to invite

their carrying away is a former flourishing growth of

vegetation attested, but over large adjoining areas of

desert search has brought the like past tenancy to light.

Fragments of what once were trees have been picked

up in the Little Colorado basin and in the neighbor

hood of Ash Fork, on both sides, that is, of the present

forest crown that covers the higher part of the plateau

from which rise the San Francisco Peaks. In the blue

distance the mountains look down verdure-clad upon

a now encircling waste, but one which in earlier eras

was as pine-bearing as they. Their lofty oasis is all

that is now left of a once fertile country; the retreat

of the trees up the slopes in consequence of a dimin

ishing rainfall, until a rise of two thousand feet from

what once was timber-land is necessary to reach the

tree-line of today, being typical of desert lands, and

testifying to greater aqueous affluence in the past.

In the same manner streams descend from the cedar
chap, xiii THE REDDISH-OCHRE TRACTS 153

clad range of the Lebanon to lose themselves in the

Arabian desert just without the doors of Damascus;

and Palestine has desiccated within history times.

Palestine, a land once flowing with milk and honey,

can hardly flow poor water now, and furnishes another

straw to mark the ebbing of the water supply.

This making of deserts is not a sporadic, accidental,

or local matter, although local causes have abetted or

hindered it. On the contrary, it is an inevitable result

of planetary evolution, a phase of that evolution which

follows from what has been said in Chapter XII on

the abandonment of a planet by its water. Deserts

are simply another sign of the same process. The very

aging which began by depriving a body of its seas

takes from it later its forest and its grass. A growing

scarcity of water is bound to depauperate the one, as it

depletes the other. We have positive proof of the

action in our own deserts. For these bear testimony,

in places at least, to not having always been so, but

to have gradually become so within relatively recent

times. But we have more general proof of the action

from the position occupied on the earth's surface by its

deserts.

The significant fact about the desert-making so

stealthily going on is that only certain zones of the

earth's surface are affected. Those belting the two

tropics of Cancer and Capricorn, for several degrees
154 MARS AND ITS CANALS chap, xm

on either side of them, most exhibit the phenomenon.

Such positioning of the deserts is not due to chance.

Directly, of course, desertism is due to dearth of rain.

This in turn depends on the character and condition

of the winds. If a wind laden with moisture travel

into a colder region of the globe, its moisture is pre

cipitated in rain and we have a fertile country; if it

voyage into a warmer clime it takes up what little

moisture may be there already and a desert is the

result.

Now our system of winds is such as to produce a fall

of rain for the different latitudes, as tabulated by

Supan, thus: —

Zone I 40°N-27°N Little rain in summer but much in winter.

II 27 N-19 N Little rain at all seasons.

III 19 N- 7 N Little rain in winter but much in summer.

IV 7 N- 1 N Abundant rain at all seasons.

V 1 N-17 S Lit tle rain in winter but much in summer.

VI 17 S-30 S Little rain at all seasons.

VII 30 S-35 S Little rain in summer but much in winter.

Zones II and VI, the zones of minimum rainfall, are

also those in which the deserts occur. The northern

one traverses southern California, Arizona, New Mexico,

the Sahara, Arabia, and the Desert of Gobi ; the south

ern, Peru, the South African veldt, and central Aus

tralia. The belts are wavy bands which by their

form betray both a general underlying trend to drought
(map, xiii THE REDDISH-OCHRE TRACTS 155

at these parallels and also the effect of local topography

in the matter.

From being distributed thus in belts, it is evident that

the deserts are general globe phenomena, and from their

being found only in the zones of least rainfall, that the

earth has itself entered, though not far as yet, upon

the desert stage of its history. Once begun, the desert

areas must perforce spread as water becomes scarce,

invading and occupying territory in proportion as the

rainfall there grows small.

Now the axial tilt of Mars is almost exactly the same

as that of our Earth, the latest determinations from

the ensemble of measures giving 24° for it. Here, then,

we have initial conditions reproducing those of the

earth. But from the smaller size of the planet that

body would age the earlier, since it would lose its inter

nal heat the more rapidly, just as a small stone cools

sooner than a larger one. On general principles,

therefore, it should now be more advanced in its plan

etary career. In consequence, desertism should have

overtaken more of its surface than has yet happened

on earth, and instead of narrow belts of sterility we

should expect to find there Saharas of relatively vast

extent.

Now, such a state of things is precisely what the

telescope reveals. The ochre tracts occupy nine tenths

of the northern hemisphere and a third of the southern.
156 MARS AND ITS CANALS chap, xiii

Three fifths, therefore, of the whole surface of the

planet is a desert.

Of cosmic as well as of particular import is the corre

lation thus made evident between the physical prin-

 

Desert areas.

ciples that effect the aging of a planet and the aspect

Mars presents. Experimental corroboration of those

laws is thus afforded, while, reversely, confidence in

their applicability is increased. With continued ob

servation the planet appears more desiccate as im

proved conditions bring it nearer. Dry land as it
chap, xiii THE REDDISH-OCHRE TRACTS 157

was thought to be proves even drier, something which

lacks water for the ordinary necessities of a living

world. The picture the planet offers to us is thus arid beyond

 

Desert areas.

present analogue on Earth. Pitiless as our deserts

are, they are but faint forecasts of the state of things

existent on Mars at the present time. Only those who

as travelers have had experience of our own Saharas

can adequately picture what Mars is like and what so

waterless a condition means. Only such can understand
158 MARS AND ITS CANALS CHAP. XIII

what is implied in having the local and avoidable thus

extended into the unescapable and the world-wide ; and

what a terrible significance for everything Martian lies

in that single word : desert.
CHAPTER XIV

SUMMARY

TF, now, we review with the mind's eye the several

features of Mars which we have surveyed with the

bodily one, we shall be surprised to find to what they

commit us. Suggestive as each is considered by itself,

the ensemble into which they combine proves of multiplicate force in its implication. For each turns out

to fit into place in one consistent whole, a scheme of

things in which are present all the conditions necessary

to the existence and continuance of those processes

which constitute what we call life. In short, we are

conducted with a cogency, which grows as we consider

it, to the conclusion that Mars is habitable.

Two ways of appreciating this cogency are open to us.

We may treat it with the simple reasoning of commonsense, as we should a dissected map or a piece of ma

chinery in which we realize we are right when the

several parts at last fit together and the picture stands

revealed or the machine works. Or we may subject

the evidence to quantitative estimates for and against

by the doctrine of probabilities, and thus evaluate

the chances of its being correct. Consciously or un150
160 MARS AND ITS CANALS chap, xiv

consciously, this is what we are about in our decisions

every day of our lives. At the one end of the line are

those skillful judgments where the balance is so keenedged that the least overweight on the one side dips the

scales to a conclusion. At the other extremity stand

those deductions which we usually speak of as proved,

such as the law of gravitation. But both assurances

rest really upon probability and differ only in degree.

What we mean by proof of anything is that a suppo

sition advanced to account for it explains all the facts

and is not opposed to any of them, and that the balance

of probability in consequence is very largely in its favor.

Now, if several pieces of evidence, distinct in their

origin, concur to a given conclusion, the probability

that that conclusion is correct is far greater than what

results from each alone ; and mounts up soon to some

thing much exceeding what bettors at races call cer

tainty odds. However unversed the average man may

be in calculating the probability, he recognizes the fact

in his dealings with his fellows by the way he attaches

weight to concurrent testimony. It is such concurrent

evidence that we have now to consider. To this end

we will marshal the several facts ascertained in a sum

marized list for their easier intercomparison.

These facts are : —

(1) Mars turns on its axis in 24 h. 37 m. 22.65 s. with

reference to the stars, and in 24 h. 39 m. 35.0 s. (as a
CHAP. XIV SUMMARY 161

mean) with regard to the Sun. Its day, therefore,

is only about forty minutes longer than ours.

(2) Its axis is tilted to the plane of its orbit by about

23° 59' (most recent determination, 1905). This gives

the planet seasons almost the counterpart of our own

in character; but in length nearly double ours, for

(3) Its year consists of 687 of our days, 669 of its

own.

(4) Polar caps are plainly visible which melt in the

Martian summer to form again in the Martian winter,

thus implying the presence of a substance deposited

by cold.

(5) As the polar caps melt, they are bordered by a

blue belt, which retreats with them. This excludes the

possibility of their being formed of carbon dioxide, and

shows that of all the substances we know the material

composing them must be water.

(6) In the case of the southern cap, the blue belt has

widenings in it in places. These occur where the bluegreen areas bordering upon the polar cap are largest.

(7) The extensive shrinkage of the polar snows shows

their quantity to be inconsiderable, and points to

scanty deposition due to dearth of water.

(8) The melting takes place locally after the same

general order and method, Martian year after year,

both in the south cap,

(9) And in the north one. This is evidenced by the

M
162 MARS AND ITS CANALS chap, xiv

recurrence of rifts in the same places annually in each.

The water thus let loose can, therefore, be locally

counted on.

(10) That the south polar cap is given to greater

extremes than the north one, implies again, in view

of the eccentricity of the orbit and the tilt of the axis,

that deposition in both caps is light.

(11) The polar seas at the edges of the caps being

temporary affairs, the water from them must be fresh.

(12) The melting of the caps on the one hand and

their reforming on the other affirm the presence of

water vapor in the Martian atmosphere, of whatever

else that air consist.

(13) Since water vapor is present, of which the

molecular weight is 18, it follows from the kinetic

theory of gases that nitrogen, oxygen, and carbonic

acid, of molecular weights 28, 32, and 38 respectively,

are probably there, too, owing to being heavier.

(14) The limb-light bears testimony to this atmos

phere.

(15) The planet's low albedo points to a density

for the atmosphere very much less than our own.

(16) The apparent evidence of a twilight goes to con

firm this.

(17) Permanent markings show upon the disk, prov

ing that the surface itself is visible.

(18) Outside of the polar cap the disk is divided into
CHAP. XIV SUMMARY 163

red-ochre and blue-green regions. The red-ochre

stretches have the same appearance as our deserts

seen from afar,

(19) And behave as such, being but little affected

by change.

(20) The blue-green areas were once thought

to be seas. But they cannot be such, because they

change in tint according to the Martian season, and the

area and amount of the lightening is not offset at the

time by -corresponding darkening elsewhere;

(21) Nor by any augmentation of the other polar

cap or precipitation into cloud. It cannot, therefore,

be due to shift of substance.

(22) Furthermore, they are all seamed by lines and

spots darker than themselves which are permanent in

place; so that there can be no bodies of water on the

planet.

(23) On the other hand, their color, blue-green, is

that of vegetation; this regularly fades out, as vege

tation would, to ochre for the most part, but in places

changes to a chocolate-brown.

(24) The change that comes over them is seasonal

in period, as that of vegetation would be.

(25) Each hemisphere undergoes this metamor

phosis in turn.

(26) That it is recurrent is again proof positive of

an atmosphere.
164 MARS AND ITS CANALS chap, xiv

(27) The changes are metabolic, since those in one

direction are later reversed to a restoration of the origi

nal status. Anabolic as well as katabolic processes

thus go on there ; that is, growth as well as decay takes

place. This proves them of vegetal origin.

(28) The existence of vegetation shows that carbonic

acid, oxygen, and undoubtedly nitrogen, are present in

the Martian atmosphere, since plants give out oxygen

and take in carbonic acid.

(29) The changes in the dark areas follow upon the

melting of the polar caps, not occurring until after

that melting is under way;

(30) And not immediately then, but only after the

lapse of a certain time.

(31) Though not seas now, from their look the dark

areas suggest old sea bottoms, and when on the ter

minator appear as depressions (whether because really

at a lower level or because of less illumination is not

certain).

(32) That they are now the parts of the planet to

support vegetation hints the same past office, as water

would naturally drain into them. That such a meta

morphosis should occur with planetary aging is in

keeping with the kinetic theory of gases.

(33) Terminator observations prove conclusively

that there are no mountains on Mars, but that the

surface is surprisingly flat.
CHAP. XIV SUMMARY 165

(34) But they do reveal clouds which are usually

rare and are often, if not always, dust-storms.

(35) White spots are occasionally visible, lasting

unchanged for weeks, in the tropic and temperate re

gions, showing that the climate is apparently cold,

(36) But at the same time proving that most of the

surface has a temperature above the freezing-point.

(37) In winter the temperate zones are more or

less covered by a whitish veil, which may be hoar-frost

or may be cloud.

(38) A spring haze surrounds the north polar cap

during the weeks that follow its most extensive melting.

(39) Otherwise the Martian sky is perfectly clear;

like that of a dry and desert land.

The way in which these thirty-nine articles fit into

one another to a mortised whole is striking enough at

first sight, but becomes more and more impressive the

more one considers it. For some are due to one kind

of observation, some to another. In the taking they

are unrelated; yet in the result they agree. Equally

pregnant is the history of their acquisition. Most of

them were detected as the outcome of observations at

the opposition of 1894, and led to the theory which was

published in the writer's first book on .the subject.

Others are the result of the five oppositions that have

since occurred. These have proved entirely corrobora

tive of the previous ones and of the theory then deduced,
166 MARS AND ITS CANALS chap, xiv

and that in two distinct ways: first, by the accumu

lated evidence they have brought to the matter along

the old lines ; and, secondly, by what they have revealed

in new directions. Of these thirty-nine articles of

Martian scientific faith in observation or deduction, (9),

(10), (21), (22), (25), (27), (28), (30), (33), (35), (36),

and (38) are in whole or part new. That continued

scrutiny is thus corroborative of the earlier results, both

along the old and along new lines of investigation, war

rants additional confidence in the conclusion.

Considering, now, these counts, we see that they

make reasonably evident on Mars the presence of : —

1. Days and seasons substantially like our own;

2. An atmosphere containing water vapor, carbonic

acid, and oxygen;

3. Water in great scarcity ;

4. A temperature colder than ours, but above the

Fahrenheit freezing-point, except in winter and in the

extreme polar regions;

5.FirstVegetation. and foremost of these is air. In order to make

it possible for vital processes of any sort to take place,

the body of a planet must be clothed with an atmos

phere, by the modesty of nature, the old astronomers

would have said. Such a covering subserves two pur

poses: it keeps out the cold of space, thus permitting

the maintenance of a temperature sufficient to support
CHAP. XIV SUMMARY 167

life, and it affords a medium through which metabolism

can go on.

Now the presence of air is attested first and foremost

by the fact of change in the Martian markings, (12),

(13), (26), (28), and (35). The changes observed are

conspicuous ; are both inorganic (in the case of the polar

caps), (12), (13), and (35), and metabolic or organic, (26)

and (28), (in the case of the blue-green areas) ; that is,

they consist of building up as well as of pulling down

and are planet-wide in occurrence. Such changes

could not occur in the absence of an atmosphere. They

show that this atmosphere consists of water vapor, (5),

carbonic acid, and oxygen, (28).

The limb-light, the apparent evidence of a twilight

arc and the planet 's low albedo indicate that this atmos

phere is thin. The appearance of the surface, (35), sug

gests cold, indicative again of a thin air. Such tenuity

is in accord with what a priori principles would lead

us to expect, and tends to show that reliance on general

principles is here not misplaced, a point of some in

terest.

Lastly, the occurrence of clouds, (34), visibly floating

and traveling over the surface, and haze at times, (38),

proves in another way the existence of the medium in

which alone this could be possible.

Water is the next substance vital to planetary life.

As to its actual presence the polar caps, (4)-(12), have
168 MARS AND ITS CANALS CHAP. XIV

most to say ; as to its relative absence, the rest of the

disk, (17)-(22). The forthright conception of the polar

caps as composed of snow and ice is borne out by further

investigation into what could cause the observed phe

nomenon. Carbonic acid, the only other substance we

know capable in any way of resembling what we see,

turns out not capable of producing one important de

tail of the caps' appearance, the blue band, (5), which

accompanies them in their retreat. Water alone

could do this.

The melting of the caps shows that water vapor must

be a constituent of the Martian atmosphere. More

over, as the molecular weight of water vapor is less

than that of oxygen or nitrogen or carbon dioxide,

if the former can exist in the atmosphere of the planet,

a fortiori must these other gases. So that from this

we have knowledge of the possibility of the presence

of oxygen, nitrogen, and carbon dioxide there. From

(28)Thewenext saw that step their is theactual ascertainment existence that is demonstrated. the water is

in very small amount. The extensive melting of the

caps, (7), shows their quantity to be inconsiderable,

which is the first fact pointing to a dearth of water.

The second comes from the aspect and behavior of the

reddish-ochre regions which proclaim them deserts, (18)

and (19); the third from the detection of the char

acter of the blue-green areas as not seas, (20), (21),
CHAP. XIV SUMMARY 160

and (22). In several different ways, study of these

regions asserts their non-aquatic constitution, the

easiest to appreciate being that they are traversed

by permanent dark lines and other equally sedentary

markings, (22). No bodies of water, therefore, are to

be seen outside of the ephemeral polar seas, immediately

surrounding the caps as they melt.

This leads us to the third presence on Mars indicative

of a living world: vegetation. The other two spoke

of substances necessary to life, the premises in the case,

this one of organic existence itself, its conclusion. The

evidence consists of static testimony from the look of the

blue-green areas, (23), and of kinematic derived from

their behavior, (24), (25), (26), and (27). Vegetation

would present exactly the appearance shown by them,

and nothing that we know of but vegetation could.

But suggestive as their appearance is, it is as nothing

compared with the cogent telltale character of their

behavior. The seasonal change that sweeps over them

is metabolic, constructive as well as destructive, that is,

and proclaims an organic constitution for them such as

only vegetation could produce. In tint their metamor

phoses are those of the same substance. For the bluegreen lapses into ochre and revives again to blue-green

just as vegetation does on our own Earth at the proper

season of the year, taking both the Sun and the advent

of water into the reckoning. Furthermore, certain
170 MARS AND ITS CANALS chap, xiv

of the largest dark areas turn to a chocolate-brown at

times, which is the color of fallow ground and sugges

tive, at least, as occurring where the blue-green at other

seasons is the most pronounced. Lastly, the change

occurs at the epoch at which, from a knowledge of the

melting of the polar caps, theory demonstrates that it

ought to take place if it be due to the action of

vegetation.

That this was the case was evident from much less

information than is forthcoming today; but what is

significant, each new fact discovered about the planet

goes to show that it is unquestionably true.
NON-NATURAL PART IIFEATURES
i
CHAPTER XV

THE CANALS

TT^ROM the detection of the main markings that diversify the surface of Mars we now pass to a discov

ery of so unprecedented a character that the scientific

world was at first loath to accept it. Only persistent

corroboration has finally broken down distrust; and,

even so, doubt of the genuineness of the phenomena

still lingers in the minds of many who have not them

selves seen the sight because of the inherent difficulty

of the observations. For it is not one where confir

mation may be summoned in the laboratory at will, but

one demanding that the watcher should wait upon the

sky, with more than ordinary acumen. This latterday revelation is the discovery of the canals.

Quite unlike in look to the main features of the plan

et's face is this second set of markings which traverse

its disk, and which the genius of Schiaparelli disclosed.

Unnatural they may well be deemed ; for they are not

in the least what one would expect to see. They

differ from the first class, not in degree, but in kind;

and the kind is of a wholly unparalleled sort. While

the former bear a family resemblance to those of the

173
174 MARS AND ITS CANALS CHAP. XV

earth ; the latter are peculiar to Mars, finding no coun

terpart upon the earth at all.

Introduction to the mystery came about in thisWise,

and will be repeated for him who is successful in his

search. When a fairly acute eyed observer sets himself

to scan the telescopic disk of the planet in steady air,

he will, after noting the dazzling contour of the white

polar cap and the sharp outlines of the blue-green seas,

of a sudden be made aware of a vision as of a thread

stretched somewhere from the blue-green across the

orange areas of the disk. Gone as quickly as it came,

he will instinctively doubt his own eyesight, and credit

to illusion what can so unaccountably disappear. Gaze

as hard as he will, no power of his can recall it, when,

with the same startling abruptness, the thing stands

before his eyes again. Convinced, after three or four

such showings, that the vision is real, he will still be

left wondering what and where it was. For so short

and sudden are its apparitions that the locating of

it is dubiously hard. It is gone each time before he

has got its bearings.

By persistent watch, however, for the best instants

of definition, backed by the knowledge of what he is

to see, he will find its coming more frequent, more

certain and more detailed. At last some particularly

propitious moment will disclose its relation to wellknown points and its position be assured. First one
CHAP. XV THE CANALS 175

such thread and then another will make its presence

evident ; and then he will note that each always appears

in place. Repetition in situ will convince him that

these strange visitants are as real as the main markings,

and are as permanent as they.

Such is the experience every observer of them has

had; and success depends upon the acuteness of the

observer's eye and upon the persistence with which he

watches for the best moments in the steadiest air. Cer

tain as persistence is to be rewarded at last, the diffi

culty inherent in the observations is ordinarily great.

Not everybody can see these delicate features at first

sight, even when pointed out to them ; and to perceive

their more minute details takes a trained as well as an

acute eye, observing under the best conditions. When

so viewed, however, the disk of the planet takes on a

most singular appearance. It looks as if it had been

cobwebbed all over. Suggestive of a spider's web seen

against the grass of a spring morning, a mesh of fine

reticulated lines overspreads it, which with attention

proves to compass the globe from one pole to the other.

The chief difference between it and a spider's work is

one of size, supplemented by greater complexity, but

both are joys of geometric beauty. For the lines are of

individually uniform width, of exceeding tenuity, and of

great length. These are the Martian canals.

Two stages in the recognition of the reality confront
176 MARS AND ITS CANALS CHAP. XV

the persevering plodder: first, the perception of the

canals at all ; and, second, the realization of their

very definite character. It is wholly due to lack of

suitable conditions that the true form of the Martian

lines is usually missed. Given the proper prerequisites

of location or of eye, and their pencil-mark peculiarity

stands forth unmistakably confessed. It is only where

the seeing or the sight is at fault that the canals either

fail to show or appear as diffuse streaks, the latter being

a halfway revelation between the reality and their not

being revealed at all. Much misconception exists on

this point. It has been supposed that improved at

mospheric conditions simply amount to bringing the

object nearer by permitting greater magnification with

out altering the hazy look of its detail.1 Not so. They

do much more than this. They steady the object much

as if a page of print from being violently shaken should

suddenly be held still. The observer would at once

read what before had escaped him for being a blur.

So is it with the canals. In reality, pencilings of ex

treme tenuity, the agitations of our own air spread them

into diffuse streaks; an effect of which any one may

assure himself by sufficiently rapid motion of a drawing

in which they are depicted sharp and distinct, when he

will see them take on the streaky look. As the writer

has observed them under both aspects, and has seen

1 M. l'abbd Moreux.
CHAP. XV THE CANALS 177

them pass from the indefinite to the defined as the

seeing improved, he has had practical proof of the fact,

and this not once, but an untold number of times.

Atmospheric conditions far superior to what are good

enough for most astronomic observations are needed

for such planetary decipherment, and the observer

experienced in the subject eventually learns how allimportant this is. Under these conditions the testi

mony of his own eyesight upon the character of these

markings that then isemerges definitefrom and confusion complete. is And that the first markings trait «

are lines; not simply lines in the sense that any suffi

ciently narrow and continuous marking may so be

called, but lines in the far more precise sense in which

geometry uses the term. They are furthermore straight

lines. As Schiaparelli said of them : they look to have

been laid down by rule and compass. The very marvel

of the sight has been its own stumbling-block to recog

nition, joined to the difficulty of its detection. For not

only is the average observatory not equipped by nature

for the task, but what is not good air often masquerades

as such. Trains of air waves exist at times so fine

as to confuse this detail, or even to obliterate it entirely;

while at the same time they leave the disk seemingly

sharp-cut, with the result that one not well versed

in such vagaries thinks to see well when in truth he is

debarred from seeing at all. When study of the condiN
178 MARS AND ITS CANALS CHAP. XV

tions finally ends in putting him upon the right road,

the sight that rewards him can hardly be too graphi

cally described.

Next to the fact that they are lines, definiteness of

direction is the chief of their characteristics to strike

the observer. The lines run straight throughout their

course. This is absolutely true of ninety per cent of

them, and practically so of the remaining ten per cent,

since the latter curve in an equally symmetric manner.

Such directness has I know not what of immediate impressiveness. Quite unlike the aspect of the main

markings, which show a natural irregularity of outline,

these lines offer at the first glance a most unnatural

regularity of look. Nothing on Earth of natural origin

on such a scale bears them analogue. Nor does any

other planet show the like. They are, in fact, distinc

tively Martian phenomena. This is the first point

in which they differ from the markings we have hitherto

described. The others were generic planetary features ;

these are specific ones, peculiar to Mars.1

1 As some misrepresentation has been made on this subject through

misapprehension of the writer's observations on Venus and Mercury,

it may be well to state that the tenuous markings on both these other

planets entirely lack the unnatural regularity distinguishing the

canals of Mars. The Venusian lines are hazy, ill-defined, and non

uniform ; the Mercurian broken and irregular, suggesting cracks.

Neither resemble the Martian in marvelous precision, and have never

been called canals by the writer nor by Schiaparelli, but solely by

those who have not seen them and have misapprehended their char

acter and look.
CHAP. XV THE CANALS 179

Equally striking is the uniform width of each line from

its beginning to its end, as it stands out there upon the

disk. The line varies not in size throughout its course

any more than it deviates in direction. It counterfeits

a telegraph wire stretched from point to point. Like

the latter seen afar, the width, too, is telegraphic. For

it is not so much width as want of it that is evident.

Breadth is inferable solely from the fact that the line

is seen at all, and relative size by difference of insist

ency. Indeed, the apparent breadth has been steadily

contracting as the instrumental, atmospheric, and per

sonal conditions have improved. All three of the

factors have conduced to such emaceration, but the

middle one the most. For the air waves spread every

marking, and the effect is relatively greatest upon those

which are most slender. As the currents of condensa

tion and rarefaction pulse along, their denser and their

thinner portions refract the rays on either side of their

true place, and thus at the same time confuse a mark

ing and broaden it. The consequence is that the better

the atmospheric conditions and the more that has been

learned about utilizing them, the finer the lines have

shown themselves to be.

Herein we have a specific intrinsic difference between

the fundamental features and these lines: the main

markings have extension in two dimensions, the latter

in one.
180 MARS AND ITS CANALS CHAP. XV

Distinctive as they thus are, they have, in keeping with

their appearance, been given a distinctive name, that of

canal. Useful as the name is and, as we shall later see,

applicable, it must not be supposed that what we see

are such in any simple sense. No observer of them has

ever considered them canals dug like the Suez Canal

or the phoenix-like Panama one. This supposition

is exclusively of critic creation.

Their precise width is not precisable. They show

no measurable breadth and their size, therefore, ad

mits for certain only of an outside limit. They cannot

be wider than a determinable maximum, but they may

be much less than this. The sole method of estimating

their width is by comparison of effect with a wire of

known caliber at a known distance. For this purpose

a telegraph wire was stretched against the sky at

Flagstaff, and the observers, going back upon the mesa,

observed and recorded its appearance as their stations

grew remote. It proved surprising at what great dis

tances a slender wire could be made out when thus projected against the sky. The wire in the experiment ■

was but 0.0726 of an inch in diameter and yet could be

seen with certainty at a distance of 1800 feet, at which

point its diameter subtended only 0.69 of a second of

arc. How small this quantity is may be appreciated

from its taking more than ninety such lines laid side

by side to make a width divisible by the eye. Such
CHAP. XV THE CANALS 181

slenderness at the then distance of Mars would corre

spond, under the magnification commonly used, only

to three quarters of a mile. Theoretically, then, a line

three quarters of a mile wide there should be visible

to us. Practically, both light and definition is lost

in the telescope, and it would be nearer the mark to con

sider in such case two miles as the limit of the percep

tible. With the planet nearer than this, as is often the

case, the width which could be seen would be propor

tionally lessened. Perhaps we shall not be far astray

if we put one mile as the limiting width which could be

perceived on Mars at present, with distance at its least

and definition at its best.

That so minute a quantity should be visible at all

is due to the line having a sensible length and by sum

mation of sensations causing to rise into consciousness

what would otherwise be lost. A stimulus too feeble

to produce an effect upon a single retinal rod becomes

recognizable when many in a row are similarly ex

cited.

The experiment furnished another criterion, of im

portance as regards the supposition that the lines on

Mars are illusory. It showed that brain-begotten im

pressions of wires that did not exist could be told from

the real thing when the wire subtended 0.69 of a second

of arc or more; that below this the outside stimulus

was too weak to differ recognizably from optic effects
182 MARS AND ITS CANALS CHAP. XV

otherwise produced; while when the real wire was

diminished to 0.59", it could not be seen at all. Now,

the majority of lines on Mars so far recognized and

mapped lie in strength of impression far above the

superior limit of 0.69". To one versed in Martian canal

detection there is no possibility of self-deception in the

case, the canals being very much more salient objects

to an expert than those who have not seen them sup

pose. For it must not be imagined that, when one

knows what to be on the lookout for, they are the diffi

cult objects they seem to the tyro. Just as the satel

lites of Mars were easily seen once they were discovered,

so with these lines.

A mile or two we may take, then, with safety as the

smallest width for one of the lines. The greatest was

got by comparing what is by far the largest canal, the

Nilosyrtis, with the micrometer thread. From such

determination it appeared that this canal was from

25 to 30 miles wide. But it is questionable whether

the Nilosyrtis can properly be termed a canal, so

much does it exceed the rest. It is certainly far

larger than the majority of them. From comparative

estimates between its size and that of the others, 15

to 20 miles for the width of the larger of the Martian

canals seems the most probable value, and 2 or 3

miles only of the more diminutive of those so far

detected.
CHAP. XV THE CANALS 183

On the other hand, the length of the canals is rela

tively enormous. With them 2000 miles is common;

while many exceed 2500, and

the Eumenides-Orcus is 3540

miles from the point where

it leaves the Phoenix Lake

to the point where it enters

the Trivium Charontis. This

means much more on Mars

than it would on Earth,

OWing tO the smaller size of Showtag the Eumenide^Otcag.

the planet. Such a length exceeds a third of the

whole circumference of its globe at the equator.

But what is still more remarkable, throughout the

whole of the long course taken by the canal, it swerves

neither to the right nor to the left of the great circle

joining the two points.

Of these several peculiarities of the individual canal

it is difficult to know to which to allot the palm for

oddity, —great circle directness, excessive length, want

of width, or striking uniformity. Each is so anomal

ously unnatural as to have received the approving

stamp of incredulity. Yet so much, wonderful as it is,

is encountered on the very threshold of the subject.

 
CHAPTER XVI

THEIR SYSTEM

UCHsuggestiveness more standsthe beyond. individual traits For, outdoing of the lines,in

is the relation shown by them to one another. It is

the communal characteristics of the phenomenon that

are most surprising.

The individual peculiarities of the lines impress

themselves at once ; the communal, only as the result

of experience, collation, and thought. As the observer

becomes trained, the more lines he is able to make out,

until they fairly seam the whole surface of the light

areas of the planet. Their name collectively is legion ;

while to name them individually is fast getting, for the

number detected, to be impossible. As with the in

creasing family of asteroids, figures alone will prove

adequate to the task.

Interdependence, not independence, marks the atti

tude of the canals. Each not only proceeds with abso

lute directness from one point to another, but at its

terminals it meets canals which have come there with

like forthrightnessfrom other far places upon the planet.

Nor is it two only that thus come together at a com

mon junction. Three, four, five, — up to as many as

 

18-1
chap, xvi THEIR SYSTEM 185

fourteen, — thus make rendezvous, and it is a poor

junction that cannot show at least six or seven. The

result is a network which triangulates the surface of the

planet like a geodetic survey into polygons of all shapes

and sizes, the Arian areolas. The size of the pieces

forming this tesselate ground depends solely upon the

fineness of the definition. With every increase in the

power of seeing, each areola is cut into still smaller

portions, usually by connection between its corners.

Thus a polygon or rhombus is split into triangles which

may themselves be divided in like manner, the mosaic

breaking into bits, the sides of which, however, always

remain clean-cut.

From this arrangement it is at once evident that the

canals are not fortuitously placed. That lines should

thus meet exactly and in numbers at particular points,

and only there, shows that their locating is not the out

come of chance. If very thin rods be thrown hap

hazard over a surface, the probability that more than

two will cross at the same point is vanishingly small.

Increasingly assured is it that this would not happen

generally. The result we see is therefore not a matter

of chance, but of some law working to that end.

To the detection of what that law is precedes the

easier ascertainment of what it is not. The lines, for

example, cannot be rivers, which was the first explana

tion offered of them by Proctor many years ago, be
186 MARS AND ITS CANALS chap, xvi

cause of their peculiar straightness. Nor can they be

channels, the name given to them by Schiaparelli,

except in the non-committal sense in which he used the

term. For here again their geometric regularity is bar

to any estuary-like hypothesis. For quite another rea

son they cannot be cracks, because of their uniform

size throughout. Their unbroken character is another

fatal objection to the same suggestion. For cracks in

ground never pursue for any great distance a continu

ous course, any more than they keep uniform or straight.

The state of an old ceiling is a case in point. When it

breaks, it does so in fissures that proceed a certain way,

then give out to be continued by others roughly parallel

to the first, but parted from them. The same char

acter is shown by the rills on the moon. The ' Straight

Wall, ' so called, is composed of three such sections, and

the little rill to the right of it, west of Birt, of four.

Thus were they seen at Flagstaff, and as, to the

writer's knowledge, they have not been so depicted

elsewhere, the fact may serve to give some idea of the

definition there.

That the underlying cause is not explosion or con

traction is also evidenced by the canals collectively

as well as individually, their arrangement into a sys

tem, for cracks, however produced, could only origi

nate from certain centres and could not fit into those

starting from others, as the canals invariably do. For
CHAP. XVI THEIR SYSTEM 187

each canal goes as undeviatingly to one terminal as it

left forthrightly from another. If one wishes to see

what explosion or contraction can do, he has only to

look at the moon through ah opera-glass, when he will

be shown a very different sight from what the drawings

of Mars detail. Thus just as, considered individually,

the lines cannot be watercourses because of their

straightness, so they cannot be cracks because of dove

tailing into one another.

The fact that they form a system shows that what

ever caused them operated over the whole planet, linked

in cause as in effect throughout each section. This at

once negatives any purely physical cause of which we

have cognizance. For upon a globe still so subject to

physical vicissitude as Mars by its aspect shows itself

to be, latitude must tell in the phenomena its zones

exhibit. Polar snows that wax and wane speak of

arctic conditions very diverse from temperate and

tropic states, and what would affect the one could not

influence the other. Yet the mesh rises superior to

zonal solicitation as to local barrier. It is not some

thing dependent either on the temperament or the

complexion of the globe's different parts. It tran

scends surface restriction and becomes planet-wide in its

working. The importance of this omnipresence dilates

in meaning as one dwells in thought upon it.

Ubiquitous as it is, the me^h which thus covers the
188 MARS AND ITS CANALS chap, xvi

Martian surface like a veil spread completely over it,

is unlike a veil in being of irregular texture. Not only

are the interstices of various shape and pattern, but the

mesh itself is of locally differing size. Though the

threads are straight and uniform throughout, they are

not all alike, besides being unsymmetrically inter

woven. Some are at least of ten times the coarseness

of others, and from this fact and the bo-peep effect of

our air waves all are not visible at once. In conse

quence the network is not so impressive at first glance

as it becomes upon a synthesis of the observations.

When this is done, the surface proves to be fairly

evenly cut up, as recourse to the maps printed in this

volume will amply demonstrate. These maps, as on

page 31, are made from the results of but one opposi

tion, and as at each opposition some zone is in a more

canal-showing state than others, owing to the Martian

season at the time, a still greater uniformity in canal

distribution results from a blending of many.

From the completeness of the mesh, it follows that in

the course taken severally by the canals no one direc

tion preponderates over another. Considered by and

large, the canals seom to be equally distributed round

the compass points; and this at all longitudes and

nearly all latitudes. Tropic, temperate, and even arctic

canals show a pleasing impartiality in the matter of

the course pursued. The only exceptions occur in the
CHAP. XVI THEIR SYSTEM 189

neighborhood of the pole. There a slight tendency

may be seen to a north and south setting.

Though so much is visible in a general way from the

map, it is of interest to go into the subject with more

particularity and to that end to show it statistically.

The several canals traversing each zone were therefore

counted, and the area of the zone computed. The man

ner of canal distribution thus found is given in the

following table, in the second column of which stand the

areas of the several zones upon the planet, each ten

degrees wide, except the one next the snow, and in the

third the number of canals found traversing them, re

duced to percentages of the 0°-10° zone. A fourth col

umn shows the total length of the canals in each zone,

those from 0° to 20° being taken from the 1896 globe,

those from 20° to 90° from the 1903. This is in order

to annul the effect of the seasons upon the showing of

the canals as much as possible.

Zone Area No. of Canals wtd. Acti,al Length

0°-10° 1.00 1.00 1.00

10° -20° .07 .89 .91

20° -30° .91 .93 .72

30° -40° .82 .90 .71

40° -50° .71 .78 .66

.50° -60° .58 .64 .59

60°- 70° .42 .43 .42

70° -80° .20 .30 .34

80° -85° .07 .12 .11
190 MARS AND ITS CANALS chap, xvi

The numbers continue fairly non-committal until

we begin to approach the pole, when they commence

to increase. Much the same result is got if we take

the actual canal-lengths in each zone, as the fourth col

umn shows. The crowding of the canals poleward is

marked. The canals, therefore, are phenomena that

stand in peculiar relationship to the polar cap. This

corroborates the inference about them due to their

running out of the edge of the snow. They not only

emanate from it, but they do so in numbers surpassing

what is elsewhere observable over the disk.

Otherwise is it with their departure-points. These

are not scattered haphazard over the surface, but bear

to its general features definite relations. If we consider

the map, obliterating the lines, and then seek to connect

the most salient points of the planet's topography by

direct avenues of communication, we shall find that our

putative lines fall exactly where the real ones occur.

For the most part, the real lines emanate from wellmarked indentations in the dark regions, fitted by

natural position for departure-points, what, if these

were seas, we should call their most conspicuous bays.

They thus leave in the southern hemisphere the deeper

folds of the great diaphragm, for the most part ; though

on occasion they run out of them where they will.

From equally conspicuous points in the dark northern

areas other lines proceed; while in the centre of the
CHAP. XVI THEIR SYSTEM 191

continents, the canals make for more or less salient

spots, small patches of shading like the Trivium or the

Wedge of Casius, or simply round black radiants, like

the Luci Ismenii.

From this it appears that the lines are locally de

pendent upon the general topography of the funda

mental features of the surface. For some reason they

connect the very points most suggestive of intercom

munication. As from their characteristics it is per

fectly evident that the lines are neither rivers nor

cracks, it follows that such a communicating habit is

of the most telltale character. To be so dissimilar in

kind from the main markings and yet so dependent

upon them, hints that their positioning occurred after

the formation of the main features themselves. We

reach thus from the look of the lines and their location

a most striking deduction, that the lines are not coeval

with the main markings, but have come into being later

and with reference to the general topography of the

planet. The network is not only a mesh de facto, then,

but one de jure, which, subsequent to the fashioning of

the seas and continents and what these have now be

come, has been superposed upon them .
CHAPTER XVII

GEMINATION OF THE CANALS

|jDRAUGHT with more difficulty than the detection

-■- of the lines alone is the next discovery made

upon the disk : the recognition of pairs of lines trav

ersing it.

In 1879, while Schiaparelli was engaged in scrutiniz

ing the strange canali he had discovered on the planet

the opposition before, he was suddenly surprised to

mark one of them double. Two closely parallel lines

confronted him where but a single one had previously

stood. So unaccountable did the sight seem, that he

hesitated to credit what he saw, being minded to at

tribute the vision to illusion of some sort and the more

so that it was not renewed. While he was still wonder

ing what it meant, the planet parted company with the

Earth, carrying its enigma with it.

When the two bodies again drew near to one another

in 1882, Schiaparelli set himself to watch for a recurrence

of the strange phenomenon. Before long it came, and

more bewilderingly than at first ; for not one canal

alone, but a score of them now showed in duplicate,

each presenting to his astonished gaze twin lines per

il I2
chap, xvii GEMINATION OF THE CANALS 193

fectly matched and preserving throughout their dis

tance apart. Suspecting diplopia or some other optical

trick, he tried various eyepieces to a test of the cause

but to no change in the effect. The twin lines con

tinued visible, do what he would, insisting on their own

reality in spite of all solicitation to merge. How cau

tious he was in the matter, and how unwilling at first

to believe the evidence of his eyes, is shown by the care

he took to guard against deception. It was not until

he had assured himself of the reality of the phenomena

that he believed what he had seen.

It so chanced that my first experience of the thing

was almost equally startling, so unexpected was it and

so exceedingly sharp was the definition at the time.

It was in an autumn early twilight, through air almost

perfectly still, as the light went out of the sky and the

markings on the planet began to come forth that the

Phison of a sudden showed in duplicate to me, clear-cut

upon the disk, its twin lines like the rails of a railway

track traversing Aeria. Not more vivid do those of

our transcontinental tracks appear as one sees them

stretching off into the distance upon our Western

plains. More impressive was the sight from the fact

that I was not looking for it. It simply suddenly

stood forth, this strange parallelism of pencil lines.

My surprise matched the wonder of the sight.

Since then I have witnessed it several hundred times,

o
194 MARS AND ITS CANALS chap, xvii

but never with more absolute certainty than at that

first fortunate revelation. To this distinctness is due

the amazement it then aroused. Not simply because

of its surpassing novelty, but for the insistence with

which it proclaimed itself was the effect to be ascribed.

Less well seen, doubt had robbed it of its full surprise.

It requires as a rule steady definition for its initial

unmistakable showing, if one would be instantly con

vinced. Except for such it is not usually easy to the

unpracticed, though often discernible to the expert

after it has once been seen. But that it is real no one

who had had a good view of the sight could doubt ;

still less after the experience had been repeated over

and over again.

What appears to take place is this: where pre

viously a single pencil-like line joined two well-known

points upon the disk, twin lines, the one the replica of

the other, stand forth in its stead. The two lines of the

pair are but a short distance apart, are of the same size,

of the same length, and absolutely equidistant through

out their course. It is as if a second line had in some

way been mysteriously added to the first since the

latter was last seen some weeks before. This in a word

is the phenomenon, technically called the gemination

of the canals, which has since its discovery called forth

so much comment. It is not in reality quite as simple

or as sudden as it seems, but this was the way in which
chap, xvii GEMINATION OF THE CANALS 195

the phenomenon was first seen and in which it still

continues to be criticised.

Self-assertive of reality, the double lines are patently

objective to him who is fortunate enough to see them

well. Nevertheless the great difficulty of detecting

them, and the still greater difficulty of conceiving how

such things can be, has led many not versed in the sub

ject to disbelieve and from that to attempt to explain

the sight as illusory. Scepticism seeks self-justification ;

what is hard of acceptance for its strangeness begetting

hypotheses of committed error which find easy cre

dence for their comforting conservatism. Several

such have in consequence been propounded to account

for the double canals. There is the diplopic theory

which credits them to non-focusing; the interferential

theory which would make them optical products of the

telescope; and the illusion theory which would have

them quite simply imaginary.

Inasmuch as in any research the assurance that a

phenomenon is real is the first point about it to be

established, it is a scientist's duty, not only to scan the

phenomena with jealous care to that end, but to scru

tinize every theory which would seek otherwise to

account for them — the testing such being only second

in importance to observing the things themselves.

Accordingly I have examined each of the optical theo

ries that have been advanced and critically compared
196 MARS AND ITS CANALS CHAP. XVII

what they assert and require with the results of obser

vation. The outcome of this research has proved as

negativing to any other origin for the double canals

than reality as direct observations at the telescope are

positive on the point. To show this I shall review

each in its consequences, confronting it with what the

telescope has to say on the subject ; for it is of the pith

of the matter that the reality should be as demon

strable on demand as on sight. Furthermore, I shall

do this before embarking on the general account of these

strange things, because it is vital to any interest that

one should be assured from the start of the truth of

what he is to read. The preface may seem to him ab

struse and prosy, but it will introduce him to some curi

ous optical properties and will eventually enhance his

concern by proving to him that what reads like fiction

is all the more wonderful for being fact.

/. The Diplopic Theory

Diplopia is the property of seeing double with one eye.

Surprising as it sounds it is an effect not unknown to

-students of optics, though it usually requires training

to produce. It is possible only when the eye is not

focused on the object, and is not always possible then.

From my experiments its feasibility seems to depend

upon whether the focus be beyond or before what it

should be. If the eye be focused for a point beyond the
chap, xvn GEMINATION OF THE CANALS 197

object, the object is doubled, if for a point this side of

it, the latter is simply blurred. When the double is

formed, the amount of the separation of the two images

is a function of the distance the focus is out. The

greater the discrepancy, the wider apart is the ensuing

double. Nor does the image, of a line, for example,

stop at doubling. After a certain breadth of separation

is reached a third line appears, bisecting the interval

between the other two. With yet greater widening

the third line itself splits into a pair and so the reso

lution goes on. In my own experiments I have gone

so far as to suspect a fifth line. Far from being uncon

scious, the process of producing the phenomenon is,

with some people, of difficult accomplishment. Mr.

Lampland, for instance, of the Flagstaff Observatory,

to whom we owe the first photographing of the canals,

and who sees the doubles of Mars without difficulty,

has hitherto found diplopic vision an impossible feat.

Even with the most practiced diplopia is never uncon

scious except when the object viewed, as a micrometer

wire, has nothing to locate it in space. Now, the di

plopic theory of the double canals supposes that in all

cases the eye of the observer is thus unconsciously

out of focus.

To this method of their manufacture the telescopic

phenomena prove unamenable on five counts.

1. Focusing the eye on an object is now a reflex ac
198 MARS AND ITS CANALS chap, xvn

tion, so automatic has it become ; in consequence one is

commonly directly conscious when an object is not in

focus, always so when the object presents detail. Were

such not the case we should never, except by chance,

see anything defined. Observing through a telescope,

after a modicum of practice, differs in no respect from

observing in everyday life. Consequently, that an

experienced observer should not know his business

in so primary a matter is preposterous. One may or

may not believe that "the undevout astronomer is

mad, " but that the perpetually unfocused one would

be is beyond debate.

2. Generically unlikely, the failure to focus is here

specifically out of the question. For the observer does

not use the canals to focus on for the simple reason that

he cannot. Like all delicate detail, the doubles appear

not continuously but by flashes of revelation, according

as the atmospheric waves permit of passage undis

turbed. To focus on them would be next to impossible

even were it resorted to — which it never is. By the

exponents of the theory this important fact is over

looked : the unforeseen showing of the canals and there

fore the absolute lack of complicity of the eye in the

matter. What one focuses on is the look of the main

markings of the disk. Now, to suppose an observer

systematically out in his perceptions of so featureful

a planet as that of Mars, so that he does not know when
chap, xvii GEMINATION OF THE CANALS 199

he sees its image sharp, implies a lack of knowledge

of astronomic observation in the supposer.

3. Study by the writer shows the width of a given

double canal to be constant for a given date. Within

the errors of perception or recording the twin lines are

always at the same epoch the same distance apart.

The greater the number of determinations made, the

nearer the result approaches to this mean; and the

greater the care used in delineation, the less each value

departs from it.

Now, if the thing were a matter of mistaken focusing,

an eye could not be thus true to its own mistakes. If

it were out in its focus by a certain amount at one time,

it would be likely to be out by a different amount at

another. So that by the very terms of its making a

diplopic double would be sure to vary. Indeed, in

laboratory experiments it is impossible to prevent it.

For the eye rests itself automatically by change of focus,

and if it be not consciously kept awry it reverts as near

to the true focus as it can of its own accord.

4. Diplopia might be a respecter of persons, but it

certainly could not be one of canals. For a given ob

server it must be objectively general in its application

to the same class of objects. Consequently, if the doub

ling were diplopic, all canals inclined at the same angle

to the vertical — for the tilt might affect the result

were the eye astigmatic — should be similarly affected.
200 MARS AND ITS CANALS CHAP. XVII

Parallel canals should parallel each other's action.

With the Martian doubles this is not the case. Of two

canals similarly inclined the one will be double, the

other not, at the same instant and under conditions

that are alike. And this persistently. For gemina

tion is an attribute of certain canals and never of others.

At a given season of the Martian year, some canals are

regularly double, some invariably single. Night after

night and presentation after presentation these idiosyn

crasies are preserved : the doubles, always pairs, the

single, always alone. Nor does the strength of the line

affect the action. The single canals are some of them

stronger, some of them weaker, than the doubles seen

at the same time.

5. If of diplopic origin the mean width of all the

doubles should be the same. For though the diplopic

width would vary for a given canal according to the

moment, a sufficient number of views would yield a

mean width which would be the same for all. Tilt

apart, the mean width of one canal would be that of

another. Among Martian doubles, on the contrary,

I have found the width to be a specific property

of the particular canal. Each has its own mean width

regardless of inclination, and this individual width

differs as between one and another by as much as five

to two, or, if we consider such canals as the Nilokcras

I and II, by more than ten to two.
chap, xvii GEMINATION OF THE CANALS 201

Any one of these five points is fatal to the theory;

a fortiori all.

//. The Interference Theory

From the wave propagation of light it follows that

the image of a bright line made by a lens is not itself

a simple bright line but a bright band flanked by alter

nate dark and bright ones. It has, therefore, been sug

gested that a bright medial line is here concerned and

that the double canal is the first of its dark pair of out

riders. But the suggestion does not bear scrutiny.

1. It presupposes a central streak brighter than the

rest of the disk to give birth to the twin dark lines.

This should itself be visible in the image ; but no such

bright backbone is seen.

2. It demands a perfectly definite width of separation

for a given aperture — which is not that observed.

3. It makes the width a function of the aperture,

decreasing as this increases — which is not sustained

by observation. Different apertures produce no effect

on the widths of the Martian doubles, as the writer has

shown (Lowell Observatory Bulletin, No. 5) by a change

of aperture from twenty-four to six inches.

4. Under like optical conditions the optically pro

duced doubles would be all of a width ; while the Mar

tian ones show idiosyncratic widths, each peculiar to

itself.

0
202 MARS AND ITS CANALS chap, xvh

///. The Illusion Theory

Known also as the Small Boy Theory from the in

genuous simplicity on which it rests, this theory attacks

the reality of the doubles by questioning that of the

canals en bloc. Because some boys from the Green

wich (Reform or) Charity School, set to copy a canalexpurgated picture of the planet, themselves supplied

the lines which had preceptorily been left out, the

Martian canals have been denied existence; which is

like saying that because a man may see stars without

scanning the heavens, therefore those in the sky do not

exist. As to the instructions the boys received we are

left in the dark. It looks as if some leading questions

had unconsciously been put to them. At all events,

English charity boys would seem to be particularly

pliant to such imagination, for when Flammarion re

tried the experiment with French schoolboys, and even

inserted spaced dots for the canals in the copy, not a

boy of them drew an illusory line.

The fact is, this is one of those deceptive half-truths

which is so much more deleterious than an unmitigated

mistake. Under certain circumstances it is quite pos

sible to perceive illusory lines, due either to shadings

otherwise unmarked and thus synthesized or to im

mediately precedent retinal impressions transferred

to places where they do not belong by rapid motion
chap, xvii GEMINATION OF THE CANALS 203

of the eye, as I had myself discovered before the

English experiment had been tried. But, as I have

also found out, these effects arc produced only at the

limit of vision, and in that limbo of uncertainty the

whole art of the observer consists in learning to dis

tinguish the true from the false. Strength of impres

sion, renewed effect in situ, and a peculiar sense of

reality or the reverse enable him to adjudge the two.

More experience than the boys possessed would have

helped them to part the sheep from the goats. But,

furthermore, and fatally to the theory here in question,

the Martian canals when well seen are not at the limit

of vision as its framers supposed, but well within that

boundary of doubt ; so that the premise upon which the

whole theory rests gives way. Under good atmospheric

conditions the canals are comparable for conspicuousness to many of the well-recognized Fraunhofer lines

and are just as certainly there.

Thus each attempt to prove the doubles nonobjective turns out when specifically examined to be in

consistent with the facts. With the assurance of their

reality thus made doubly sure, we pass to consideration

of the things themselves.
CHAPTER XVIII

THE DOUBLE CANALS

I

J) IGHTLY viewed, no more subtle tribute could be

paid to the remarkable character of the phenom

enon of gemination than the scepticism with which it

was immediately received and which it still continues

to elicit. That the sight should be regarded as illusory

speaks for its surpassing strangeness; and so far as

oddity goes the encomium is certainly deserved. Of

the bizarre features of this curiously marked disk,

the double canals were at the time of their discovery

the culmination, and though things stranger still if

possible have since been seen there, it is not wonderful

that doubt should still incredulously stare. If the mere

account of them reads like romance, to see them is an

experience.

Nothing astronomical that I have ever seen has been

so startlingly impressive as my first view of a double

canal. Even in narration the thing justifies its effect.

For a double canal consists of a pair of twin dark fila

ments, perfectly parallel throughout their course and

inclosing between them ground of the same ochreish

201
cHAP.xviii THE DOUBLE CANALS 205

cast as that which lies without. Only on occasion is

this tint of their midway departed from, and then only

toward a darkening, never toward a lightening of it.

Except for appearing paired, the lines resemble pre

cisely the usual single canals. In length they vary

from a few hundred to a few thousand miles, while in

width each component, for narrowness, hardly permits

of definite ascription.

Compared for strength with the usual canal the lines

of a double seem to hold on the average an intermediate

position between the larger and the smaller of the single

canals so far detected. Owing, however, to the massed

effect of the pair by reason of their closeness, they have

an advantage in showing over the singles of two to one.

And this renders them among the most conspicuous and

important meshes of the canal network.

Like the single canals, they vary in strength with the

Martian time of year; at certain seasons developing

into heavy pencil lines and at others fading away to the

merest gossamers, only just discernible like cobwebs

stretched across the face of the planet.

Although the individual constituent lines vary in

aspect and never rise at their most to cognizable

breadth, the distance parting their centres, or the width

of the double, is quite measurable. The only difficulty

in the way of its determination lies in the absence of a

procurable unit small enough to mete it. The usual
200 MARS AND ITS CANALS chap, xvih

spider-threads of the micrometer are colossal in com

parison with these filaments and present a standard

only analogic at best. Nevertheless, by means of the

finest threads that could be got, estimates of the dis

tance between the pairs were made at Flagstaff in 1905,

and the results agree as closely as the means permit

with those got by measurement of the doubles as

depicted in the drawings.

Of what they look like, the following illustrations

give a fair idea, only that instead of being more geofigures derived from a typical double canal, the Phison,

give some conception. This great artery of inter

communication between the Sabaeus Sinus and the

Nilosyrtis is, roughly speaking, 2250 miles long; the

distance between the centres of the two constituents

is about 130 miles, and each line is perhaps 20 miles

in breadth, when at its maximum strength. The

pair follow, apparently, the arc of a great circle from

 

Martian doubles.

metrically regular in the

drawing than in reality the

fact is the other way. Free

hand draftsmanship at the

telescope is incapable of ren

dering their ruled effect. No

railway metals could be laid

down with more precision.

As to their size, the following
chap, xvni THE DOUBLE CANALS 207

 

Martian doubles (corroborating the above).

the Portus Sigaeus on the Mare Icarium to the Pseboas

Lucus in latitude 40° north. The Portus Sigaeus con

sists of two little nicks in the coastline, looking like

the carets one makes in

checking off items down a

list, if the space between

the down and up strokes

were then filled in; the

Pseboas Lucus, on the other

hand, is a large round dot

like a small ink spot. To

these two differently appear

ing spots, the twin lines of

the Phison behave differently. While each line leaves

centrally its own caret of the Portus Sigaeus at the

south, at the north each touches peripherally the

Pseboas Lucus, on the east and west sides respectively,

the two thus just holding the Lucus between them.

In position the lines are invariable, though in visibility

not. Sometimes only one is seen, sometimes both show

faintly, and sometimes both are conspicuously strong.

The delicacy of the observations by which this detail

was established is second only to its importance. It

destroys at a stroke all possibility of diplopic un

reality, since were that the fact the Pseboas Lucus

should be doubled, which it is not. At the same time

it opens vistas into the true construction of the
208 MARS AND ITS CANALS CHAP. XVIII

things themselves, at present more suggestive than

satisfactory.

In the great circle character of its course the Phison

is quite normal. The majority of the double canals

pursue the like method, running straight over the

surface from one point to another, the constituents

remaining equidistant throughout. But such forthrightness of direction, though the rule, is not with

out exceptions. The Thoth-Nepenthes, for example,

sweeps round in a seemingly continuous curve to the

west-southwest from the Aquae Calidae to the Lucus

Moeris like some mighty bow perpetually bent. Never

theless its lines are no less careful for all their curving

to keep their distance from one end to the other of their

course. The quality of being paired rises superior to

change of direction.

II

Now, the first point to be noticed about the doubles

is that bilateralism, or the quality of being double,

is not a universal trait of the canals, either actually or

potentially; it is not even a general one. Out of the

four hundred canals seen at Flagstaff, only fifty-one

have at any time displayed the quality; that is, one

eighth roughly of the whole number observed. This

point is most important; for the fact is of itself enough

to disprove any optical origin for the phenomenon.

The characteristic of doubling so confidently ascribed
chap, xvin THE DOUBLE CANALS 209

by those who have not seen it to general optical or ocular

principles proves thus the exception, not the rule, with

the canals, and by so doing disowns the applicability

of any merely optical solution. We shall encounter

many more equally prohibitive bars to illusory expla

nation before we have done with the doubles, but it is

interesting to meet one in this manner at the very

threshold of the subject.

On the other hand, the characteristic when possessed

is persistent in the particular canal, in posse if not in esse.

Once shown by a canal, that canal may confidently

be looked to at a proper time to disclose it again.

In short, bilateralism, or the state of being dual, is an

inherent attribute of the individual canal, as idiosyn

cratic to it as position and size.

The catalogue of canals possessing this property,

so far as they have been detected at Flagstaff to date,

number fifty-one if we include in the list wide parallels

like the Nilokeras I and II. Eight of these were ob

served in 1894; nineteen more were added in 1896,

making twenty-seven; in 1901 the total was raised to

thirty; in 1903 to forty-eight; and in 1905 to fifty-one.

Arranged by years they are tabulated below, where the

numeral to the left registers for each its first recording

and the position held by it in the list. The starred

canals much exceed the others in width, and possibly

denote a different phenomenon,

p
210 MARS AND ITS CANALS CHAP. XVIII

Date Confused

1894

1. Ganges

2. Nectar

3. Euphrates

4. *Nilokeras I

and II

5. Phison

6. Asopus

7. Jamuna

8. Typhon

1896-7

Ganges Typhon

Euphrates Avermis S.

Phison

9. Lethes

Jamuna

10. Dis S.

11. Titan

12. Laestrygon

13. Tartarus

14. Cocytus

15. Sitacus

16. Amenthes

17. Adamas

18. Cerberus N.

19. Cerberus S.

20. Cyclops

21. Gelbes

22. Erebus

23. Avernus N.

24. Gigas

25. Alander

26. Gihon

27. Hiddekel

Date Confused

1900-1

Phison Dis S.

Euphrates Boreas

Hiddekel Cerberus S.

Amenthes Jamuna

Cerberus N. Pyramus

Cyclops Laestrygon

Ganges

28. Deuteronilus

Sitacus

Adamas

29. Djihoun

Gihon

30. Is

1903

Djihoun Typhon

Hiddekel Orontes

Phison

Euphrates

31. Protonilus

Gihon

32. Marsias

Amenthes

Laestrygon

Cyclops

Gigas

*Xilokeras I

and II

Ganges

Deuteronilus

33. Pierius

34. Callirrhoe

Jamuna

Sitacus
chap, xtiii THE DOUBLE CANALS 211

Date Confused Date Confused

1903 1906

35. Astaboras S. Amenthes

36. Nar Vexillum

37. Chaos Astaboras S.

38. Aethiops Adamas

39. Hyblaeus Cyclops

40. Eunostos Cerberus S.

41. Thoth Cerberus N.

42. Nepenthes Tartarus

43. Triton 49. *Propontis

44. Pyramus Gigas

45. Fretum Anian Gihon

46. Vexillum Nepenthes

Lethes Thoth

Cerberus S. Laestrygon

47. Nilokeras I 50. Polyphemus

Cerberus N. Deuteronilus

48. Tithonius Triton Eunostos

1905 Tithonius

Nilokeras Ganges Callirrhoe

Hiddekel Chrysorrhoas Pyramus

Djihoun Nar

Sitaeus Protonilus

Phison 51. Naarmalcha

Euphrates

In spite of possessing the property of pairing, a canal

may not always exhibit it. To the production of the

phenomenon the proper time is as essential as the

property itself. So far as a primary scanning or first

approximation is capable of revealing, a canal will be

single at one Martian season and double at another.
212 MARS AND ITS CANALS chap, iviii

Thus these canals alternated in their state to Schiaparelli and for the earlier of his own observed oppo

sitions to the writer. In consequence Schiaparelli

deemed gemination a process which the canal periodi

cally underwent. Three stages in the development

were to him distinguishable : the single aspect, a short

confused aspect, and the clearly dual one.

In the single state the canal remained most of the

time. It then underwent a chrysalid stage of confu

sion to emerge of a sudden into a perfect pair. Fur

thermore, he noted the times at which the pairing took

place, to the formulating of a law in the case — de

rived from the observations of more than one opposition.

His law was that the gemination occurred, on the aver

age, three months (ours) after the summer solstice

of the northern hemisphere, lasted four to five months,

then faded out to begin afresh one month after the vernal

equinox of the same hemisphere and continue for four

months more. Expressed in Martian seasonal chro

nology, the periods would be about half as long. At

certain times then the most pronounced specimens of

doubles showed obstinately single, while the periodic

metamorphosis that transformed them into duplicates

was timed to the changes of the planet's year. Gemi

nation, then, was a seasonal phenomenon.

Advance in our knowledge of the phenomenon since

Schiaparelli's time, while still showing the thing to be
chap, xviii THE DOUBLE CANALS 213

of seasonal habit, has changed our conception of it.

It now appears that in some cases certainly, and pos

sibly in all, the dual aspect is not a temporary condition,

but the differing pronouncement of a permanent state,

the fact of gemination so called being confined to a

filling out of what is always skeletonly there. As the

canals have come to be better seen, the three stages of

existence have in some cases become recognizable as

only different degrees in discernment of an essential

double condition; the single appearance being due to

the relative feebleness of one of the constituents and the

confused showing to the weakness of both, which are

then the more easily blurred by the air waves. In cer

tain canals the last few oppositions, 1901, 1903, and

1905, have disclosed this unmistakably to be the case,

as with the Phison and Euphrates, for example. With

them the double character has been continuously visible,

appearing not only when by Schiaparelli's law it should,

but at the times when it should not ; only on these latter

occasions it was harder to see, whence the reason it was

previously missed. So that further scrutiny, while in

no sense discrediting the earlier observations, has ex

tended to them some modification, and disclosed the

underlying truth to be the varying visibility, the thing

itself, except for strength in part or whole, persisting

the same. Improvement in definition has lowered the

see-level to revelation of continuous presence of the
2U MARS AND ITS CANALS chap, inn

dual state. It is only on occasion that the improvement

is sufficient for the thing when at its feeblest to loom

thus above the horizon of certainty; yet at such mo

ments of a rise in the seeing it is enough to allow it

to be glimpsed. Thus it fared with the Adamas at the

opposition of 1903, with the Gigas, and with many

another in years gone by. Separation has come with

training and generally in the case of the wider doubles,

which leads one to infer that ease of resolution is largely

responsible for assurance of the permanency of the dual

state. Perplexing exceptions, however, remain, so

that it is possible at present only to predicate the

principal of most of the double canals but not of all.

Leaving the exceptions out of account for the moment,

we pass to those general characteristics which are in

timately linked with what has just been said.

Inasmuch as the act of getting into a state antedates

the fact of being there, it is logical to let the description

of the first precede. An account of the process of gemi

nation may thus suitably come before that of its result.

Flux, affecting the double canals in whole or part,

is the cause of the apparent gemination. According

as the flux is partitive or total is a single or a dual state

produced. At the depth of its inconspicuousness the

canal may cease to be visible at all ; this occurs when

both lines fade out. On the other hand, the one line

may outfade the other, and we are presented with a
chap, xvm THE DOUBLE CANALS 215

seemingly single canal, at this its minimum showing.

In such seasons of debility the one line may appear and

the other not, or occasionally the other show and the one

not, according to the air waves of the moment. It is

at these times that the double simulates a single canal,

and unless well seen and carefully watched might easily

masquerade successfully as such. The Hiddekel in the

depth of its dead season is peculiarly given to this al

ternately partitive presentation. As the flux comes on,

one or both lines feel it. If one only we are likely to

have a confused canal ; if both, a difficult double. The

strength of the lines increases until at last both attain

their maximum, and the canal stands revealed an un

mistakable pair, the two lines paralleling one another

in appearance as in position.

At the canal's maximum and minimum the equality

of its two constituents is chiefly to be remarked, though

it occurs on other occasions as well. But, what is signifi

cant, when the two differ it is always the same one that

outdoes its fellow. It may be the right-hand twin in

one pair, the left-hand one in another; but whichever

it be, for the particular canal its preeminence is in

variable. It is this canal which, except for adventitious

help or hindrance from the air-waves, alone shows

when the double assumes the seemingly single state.

We may therefore call it the original canal, the other

being dubbed the duplicate. In some cases it has been
216 MARS AND ITS CANALS CHAP XVIII

possible to decide which is which. It might seem at

first sight as if this point should always be ascertainable.

But the determination is more dilemmic than appears,

not from any difficulty in seeing the canal, but from the

absence of distinguishing earmark at its end. In a

long stretch of commonplace coast, the precise point of

embouchure of a solitary canal cannot be so certainly

fixed as to be decisive later between two which show

close together in the same locality. It is only where

some landmark points the canal's terminal that the

problem admits of definite solution. This telltale

tag may be a bay like the Margaritifer Sinus, or double

gulfs like the Sabaeus Sinus, or portions of a marking

not too large to permit of partitive location like the

Mare Acidalium, or a canal connection like the Tacazze

which prolongs the one line and not the other. In these

and similar instances the two lines become capable of

identification, those comprisedandininthesuchfollowing manerlist: have— been found

Double Canal Original Line Date of Ascertainment

Phison The Eastern 1894 Euphrates The Western 1894 Titan The Western 1896 Hiddekel The Eastern 18% Gihon The Western 1896 (iigas The Northwestern 1896 Djihoun The Western 1901 Laestrygon The Eastern 1903 Nilokeras I and II The Northern 1903 Astaboras The Southern 1903 Jamuna The Eastern 1905 Ganges The Western 1905
CHAP. XVIII THE DOUBLE CANALS 217

In this list of originals the canals stand chrono

logically marshaled according to date of detection.

The Phison and Euphrates were the first to permit of

intertwin identification in 1894, while the Jamuna and

Ganges were the last to be added to the column in 1905.

The list is not long, though the time taken to compile it

was. In the case of the Ganges and the Jamuna, for

example, although suspected for some time on theo

retic grounds, it was only at the opposition just passed

that the fact was observationally established. In

his Memoria V, Schiaparelli has a list of similar detec

tion, and if the present list be compared with his, the

two having been independently made, the concordance

of the result will prove striking, corroborative as it is

of both. For the necessary observations are very

difficult.

Having thus realized the original by means of its

superior showing, and then identified it by its position,

it is suggestive to discover that the duplicate betrays

its subordinate character, not only by its relative insig

nificance, but by its secondary position as well. The

original always takes its departure from some wellmarked bay, seemingly designated by nature as a de

parture-point, or from a caret belonging clearly to itself ;

the adjunct, on the other hand, leaves from some neigh

boring undistinguished spot, as in the case of the addi

tional Djihoun, or makes use of a neighbor's caret, as in
218 MARS AND ITS CANALS CHAP. XVIII

the case of the second Phison and the supplementary

Euphrates. In either case it plays something of the

part of an afterthought ; and yet the postscript when

finished reads as an integral part of the letter. An

example will serve to make the connection evident while

leaving the character of the connection as cryptic as

ever.

In the long stretch of Aerial coastline bounding the

Mare Icarium, which sweeps with the curve of a fore

time beach from the Hammonis Cornu to the tip of

the Edom Promontory, there stand halfway down its

far-away seeming sea-front two little nicks or indenta

tions. Even in poor seeing they serve to darken this

part of the coast while in good definition they come out

as miniature caret-like bays. They are the Portus

Sigaei, and mark the spots where the Phison and the

Euphrates respectively leave the coast. About four

degrees apart, the eastern makes embouchure to the

original Phison, the western to the original Euphrates,

and each in some mysterious manner is associated not

only in position but in action with the canal itself.

In the single state each canal leaves the Mare from

this its own caret, the Phison proceeding thence north

east down the disk, the Euphrates nearly due north,

so that starting four degrees apart at the south they

are forty degrees asunder at their northern termini.

Clearly at these latter points they are not even neigh
chap,xviii THE DOUBLE CANALS . 219

bors, and except for the accident of close approach at

their other ends have nothing in common anywhere.

And yet when gemination takes place a curious thing

occurs: each borrows its neighbor's terminal as de

parture-point for its own duplicate canal. Having thus

got its base the replica proceeds to parallel its own

original canal without the least reference to the other

canal whose own caret it has so cuckoo-wise appro

priated. What

the Phison thus

Phison. In this m

manner is produced an interrelation which suggests,

without necessarily being, an original community of

interest; suggests it on its face and yet appears to be

rather of the nature of an adaptation to subsequent

purposes of a something aboriginally there.

That such latter-day appropriation is the fact is

clearly hinted by the behavior of another understudy

of an original canal, in this case the duplicate of the

Djihoun, which in consequence of the position of its

original finds no neighboring embouchure already

convenient to its use. The single or original Djihoun

does to the Eu

phrates, the Eu

phrates returns

the compliment

by doing to the

 

 
220 MARS AND ITS CANALS chap, xviii

leaves the tip of the needle-pointed Margaritifer Sinus,

which serves a like end to the Oxus and the Indus, both

single canals. The Sinus is itself a single bay, and so

large that for many degrees its shores on both sides con

verge smoothly to their sharp apex. Because of this

probably, the coast in the immediate neighborhood is

without canal connection, no canal being known along

either side till one reaches the Hydraotes at the Aromaticum Promontorium, which marks the western limit

of the gulf. The consequence is that when the Djihoun doubles, the duplicate canal, not having any ter

minus ready to its hand, has to make one for itself

by simply running into the Margaritifer Sinus, some

distance up its eastern side. It thus advertises its adjunctival character, and at the same time the general

fact that aneighbor's terminus, though used from prefer

ence, when convenient, is not an essential in the process.

Gemination occurs of its own initiative, but is condi

tioned by convenience.

Whether one canal shows thus to the exclusion of the

other, or whether both stand so confused as not to be

told apart, the fact remains that the double is not always

recognizable as such. If we turn to the list of thedoubles on page 222, we shall note that the same canals

were not always seen in the dual condition at successive

oppositions. Some, indeed, are so emphatically of the

habit as to appear year after year in a paired state, but
chap, xviii THE DOUBLE CANALS 221

others are not so constant to their possibilities. Now,

when it is remembered that at different oppositions we

view Mars at diverse seasons of its tropical year, we see

that this means that the phenomenon is seasonal;

and furthermore that its exhibition depends upon the

canal's position. Gemination, like the showing or nonshowing of the single canal, is conditioned by the place

of the canal upon the planet.

in

Turning from such generic characteristics to more

specific traits, the first thing to strike an attentive ob

server is that the doubles differ in width ; that they are

not mensurably alike in the property they hold in com

mon of being paired. In some the twin lines are ob

viously farther apart than in others, and the relation

persists however repeated the observations. Of two

doubles the one will always surpass its fellow. This

contrasted individuality first struck me in the Phison

and the Euphrates; and from the first moment at

which these doubles showed as such. The Phison pair

seemed perceptibly the narrower of the two. A like

distinction was evident at the next opposition and

the next; in fact, at every succeeding one to the

present day. Nor was the recognition of the fact

confined to me. If we turn to Schiaparelli's Memoriae

we shall find that that master had registered the same
222 MAES AND ITS CANALS CHAP. XVIII

idiomatic width for the two canals from first to last

throughout his long series of records. The observation

thus made proved to apply to each and all of these

curious twins.

Diversity in width for different doubles appears

plainly in drawings where more than one double is

depicted. As an example, two drawings are here

given in the text, made, the one on July 13, 1905, X15°,

and the other on July 20, X313°. In them the Phison,

Euphrates, Djihoun, and Thoth appear contrasted as

unmistakably as either of them does with the single

canals apparent at the same time. That this drawing

is typical is borne out by all the best measures of the

several doubles as seen at successive oppositions, and

marshaled in the subjoined list. How truly individual

the quality is stands proved by the relative values in

different years which are even more accordant than the

absolute ones.

The canals were : —

Width

1903 1905 Mean

f

1. Phison . .

2. Euphrates .

3. *Protonilus .

4. Deuteronilus

3.5

4.0

2.8

2.2

3.4

4.2

2.0

2.4

3.4

4.1

2.4

2.3

* Poor.
chap, xviii THE DOUBLE CANALS 223

1903

Width

1905 Mean

0

5. 2.5 2.5

6. 2.5 *2.1 2.3

7. ♦Hiddekel 3.8 4.9 4.3

8. *Gihon 3.9 4.9 4.4

9. 2.0 1.9 1 9

10. 3.8 *3.3 3.6

11. 4.5 — 4.5

12. 5.0 5.2 5.1

13. 11.0 11.7 11.3

14. 2.3 2.3

15. 3.5 — 3.5

16. 2.2 — 2.2

17. Cerberus N 4.0 — 4.0

18. 4.0 — 4.0

19. 2.9 *2.2 2.6

20. Nar 2.6 2.0 2.3

21. 2.8 2.8

22. 3.3 — 3.3

23. 2.8 — 2.8

24. 2.9 — 2.9

25. 3.2 — 3.2

26. 3.0 — 3.0

27. 3.2 3.5 3.3

28. Thoth 2.8 2.3 2.5

29. 2.8 2.3 2.5

30. 2.7 *2.3 2.5

31. 2.9 *2.0 2.5

32. Astaboras S 3.2 3.1 3.1

33. 2.6 2.2 2.4

34. 3.5 2.9 3.2

35. Tartarus — 2.7 2.7

* Poor.
224 MARS AND ITS CANALS chap, xvm

Here we have widths ranging from eleven degrees to

two. The widths given are those when the canal was at

or sufficiently near its full strength, and are measured

from the centres of the constituents. We notice two

points: the agreement of the same canal with itself

and its systematic disagreement with others. But

what is especially to the point, if we compare the values

found at successive oppositions, we find that for differ

ent canals the values agree in their difference. This

shows that each of these values is, in most cases if not

in all, a norm for that particular canal; a value dis

tinctive of it and to which it either absolutely or rela

tively conforms. In other words, the width of the

gemination is a personal peculiarity of the particular

canal, as much an idiosyncrasy of it as its position on

the planet.

Two general classes may be distinguished; those up

to about five degrees in width apart and those above

this figure. Whether such very widely separated lines

as go to make up the second class, such as the Nilokeras

I and II, constitutes a double is a debatable point.

Schiaparelli thought they did, and so classed them.

To me it did not at first occur so to consider them,

and in some instances, such as the Helicon I and

II, later observations seem to justify the omission.

With the Nilokeras I and II the outcome seems the

other way. The reasons for distrust of a physical rela
chap, xvm THE DOUBLE CANALS 225

tion between the constituents is not so much the dis

tance separating them, nor any lack of parallelism, as

the self-sufficient manner in which they show alone.

Even this, however, tends to be recognized in the nar

rower pairs as they come to be better seen. It may

be that width alone is wholly competent to selective

showing. For the farther apart two lines are on the

planet, the more opportunity is afforded the air waves

to disclose the one without the other, a relative revela

tion which is constantly happening to detail in different

parts of the disk. As long as any doubt exists of, a

physical community of interest, it seems best to dis

tinguish such possibly merely parallel canals by suffixed

numerals.

Of this class of doubles is the Nilokeras I and II.

So wide is it that Mr. Lampland succeeded in photo

graphing it as such, the two constituents showing well

separated, and if it prove a true double it will be the

first Martian double to leave its impress on a sensitive

plate. Although separated by four hundred miles of

territory, the two lines are parallel so far as observa

tion can detect, which, of course, is not so very easy

with the lines so far apart. In the country between

one crosswise canal certainly lies, the Phryxus, and

much shading thus far unaccounted for. Recent dis

coveries, however, point to the cause of such shading as

lines imperfectly seen. For in some cases the lines
226 MARS AND ITS CANALS chap, xvm

have actually disclosed themselves, and warrant us in

believing that it is only imperfect seeing that keeps the

others hid. Of the pair the Nilokeras I is itself double,

curiously reproducing what sometimes is seen in the

case of double stars, one of whose components turns

out to be itself a binary. The second line of the Niloke

ras I lies close to its primary on the north, and was on

the only occasion of its detection the merest of gossa

mers, while the Nilokeras I itself stood out strong and

dark. Thus do these Martian details increase and mul

tiply in intricacy the better the seeing brings them out.

In the case of the other doubles, the doubles proper

so to speak, there is every indication of a physical bond

between the pair. What that bond may be is another

matter and seems to be of different divulging, according

to the particular instance. At one end of the subject,

both as the widest of these doubles and one of the most

important, stands the Ganges. The components of

the canal are 5°.l apart. This great width, joined to

the fact of scant extension, gives the canal a stocky

aspect, its breadth being but one sixth of its length.

Its width draws attention to it while the phenomena

it exhibits intrigue curiosity.

As early as the first opposition of my observations

in 1894, the canal, as it underwent the process of

doubling, showed phases of peculiarity. It was first

caught by me as a double over toward the terminator,
chap, xviii THE DOUBLE CANALS 227

or fading edge of the disk ; then as it was brought nearer

the centre by the gaining upon the longitudes, showed

as a broad swath of shading of a width apparently equal

to any it later exhibited. In this appearance it con

tinued for some months, and then in October began to

show a clarification toward the centre. Once started,

the lightening of its midway advanced till at last, on

November 13, it stood out an unmistakable double, the

two lines standing where the edges of the swath had

previously been. Had the observations here been all

that one could wish, the method of gemination would

have been certain and of great interest. Unfortunately,

the observations left much to be desired, and those re

peated in 1896-1897 and 1901 were of like doubtful

ness. A period of swarthy confusion preceded the

plainly dual state, but whether the double simply

clarified or widened as well it was not possible to assure

one's self. That the canal exhibited plainly the effects

of seasonal development was as unmistakable as the

steps themselves were open to ambiguity. In 1903

the canal was at its minimum and hardly to be made

out. It seemed then to show an actual change in

width coincident with alteration of visibility. But

this, too, could not be predicated with certainty. It

was also surmisable that the westernmost line was

the one from which the development proceeded.

In 1905 much more was made out about it, training
228 MARS AND ITS CANALS chap, xviii

in the subject and increased proximity of the planet

contributing to the result. It now became clear to

me that the canal did develop from the western side;

for the western edge made

a dark line of definite bound

ary from which shading pro

ceeded to the eastern side,

where it faded almost imper

ceptibly off with no defined

line to mark its limit. That

this shading gradually dark- Peeuliar development of the when it could Ganges. be seen atened all itwasextended evident,tobutthe that ex

treme limit of the eventual double, restricted the

character if not the fact of an actual widening. At

this opposition, too, the canal passed through its

period of minimum visibility and was then seen,

whenever it could be caught, as a confused swath of

full width. In the case of this canal, then, a widen

ing in the sense of a bodily separation of two lines

seems inadmissible. On the other hand, the gradual

darkening of the swath, and especially the advance of

the darkening from the western side, points to an

interesting process there taking place.

At the opposite end of the series stands the Djihoun.

As the Ganges is the widest of the instantly impressive

doubles, so the Djihoun is the narrowest the eye has so

 
chap, xviii THE DOUBLE CANALS 229

far been able to make out. Only two fifths of the

width of the Ganges pair, this slender double is very

nearly at the limit of resolvability. So well propor

tioned are its lines to the

space between them, how

ever, that in ease of recogni

tion it surpasses many wider

pairs. In form, too, it is dis

tinctive, turning by a grace

ful curve the trend of the

Margaritifer Sinus into the

LUCUS IsmeniuS. With its Djihoun, the narrowest double.

fundamental branch — the northern of the two —it

joins what is evidently the main line of the Protonilus — also the northern one — to the Margaritifer

Sinus's tip.

It differs from the Ganges in some other important

particulars besides width. In its case no band of shad

ing distinguishes it at any time. It has always been

two lines whenever it has been seen other than as a

single penciling; the only confusion about it being

evidently our own atmosphere's affair. These two

lines, furthermore, have showed, within the errors of

observation, always the same distance apart. So that

not only no change of intercommunication between the

lines but no change in their places apparently occurs.

Between these extremes in width, two hundred miles

 
230 MARS AND ITS CANALS chap, xviii

more or less for the Ganges and seventy-five miles for

the Djihoun, the distance parting the pairs of most of

the double canals lies. From 3° to 3°. 2 on the planet

may be taken as that of the average ; the degrees denot

ing latitudinal ones on the surface of Mars, the length

of which is equal to thirty-seven of our English statute

miles.

Most of the canals conform Apparently to the type

of the Djihoun rather than to that of the Ganges.

Careful consideration of them fails to find any increase

or decrease of distance, between the pairs of the same

canal at different times, which cannot be referred to

errors inevitable to observation of such minute detail.

In short, the double is made by the addition of a sec

ond line in a particular position and not by a growth

out to it of a line coincident to begin with with the first.

I have said that the average width between the two

lines of the doubles was about 3°. It must not be

supposed that this average width denotes anything

more than an average; or, in other words, that it de

notes anything in the nature of a norm. The remark

is important in view of a suggestion which I have heard

made that we have here a system based on fundamental

Martian units, in which, or in multiples of which, the

dimensions of the canals are implicit ly expressed. Such,

however, does not seem to be the case. In some in

stances, indeed, we have certain evidence to the con
chap,xviii THE DOUBLE CANALS 231

trary and that the width of the double is conditioned

solely by antecedent place. The Phison and Euphrates

offer a case in point. These two important arteries

in duplicate leave, as we saw, from two carets in the

Mare Icarium, the Portus Sigaei, held in common ten

ancy by both. Each pair then proceeds down the disk

inclined at its own particular angle to the meridian in

order to reach by a great circle course a certain spot;

the Pseboas Lucus in one case, the Luci Ismcnii in the

other. As one of these angles is thirty-five degrees

while the other is only three, they must, from the

circumstances of their setting out, have not only

different widths, but widths determinately different in

advance, since each is, roughly speaking, foreshortened

by the degree of divergence from the meridian. The

one, therefore, must be about four degrees to the other's

something less than three and a half. This is what they

actually are as determined by measurement from obser

vation. That the calculated value agrees with that

found from observation helps certify to a community

of starting-points, but it completely does away with

comprehensive design in the question of their widths.

ForIndeed, if the one the were nextsoexample settled, thesemsothertocould denynotit be.to

both. This example occurs, too, not far away from

the scene of the first, in the twin bays of the Sabaeus

Sinus, from which depart, mutatis mutandis, the
232 MARS AND ITS CANALS chap, xvm

double Hiddekel and the two Gihon. These twin

gulfs bear so little imprint of being other than natural

formations, that they have been universally and very

likely quite rightly taken for such ever since Dawes

discovered them in 1859, long

before things like canals were

dreamed of. It is strange

that when the Hiddekel and

the Gihon were found by me

to be double in 1897, with a

branch of both leading from

each bay, the connection be- The Siibacus Sinus, embouchure , ,. .. ,

for the double Hiddekei and tween the sceptically scouted

uihou- doubles and the thoroughly

bolieved-in bays should have been apparent. For to

link a ghost to materiality, if it does not discredit

the materiality, serves to substantialize the ghost.

Furthermore, it shows that in this case neither the

one double nor the other can have had its width

engineered on any preconceived scale, unless the

twin bays be themselves so accounted for. So that

it seems useless to seek for cryptic standards in the

canals or to think to find them a measure of value

fromA third the fact instance of their of thebeing sameathing mediumin theof case exchange. of the

Ganges and the Jamuna was proved at the last oppo

sition after having long been suspected without my

 
chap, xviii THE DOUBLE CANALS 233

being able to make sure of it. These instances, taken

in connection with the wide range of values in the

widths presented by different canals, serve to show

that the distance between the twin lines is an individual

characteristic of the particular canal, and further to

point to its cause, in some cases certainly and possibly

in all, as topographical. The duplicate line makes a

convenience of a neighbor, and suits its distance from

its fellow to friendly feasibility. To cut a 'canal' to

conform to the country seems logical if not obliga

tory, and quite in keeping with the nomenclature of

the subject ; but here the starting-point appears to be

the only thing considered — the canal once safely

launched being left to shift, or rather not shift, for itself.

IV

Topography thus introduced to our notice for its

effect on the breadth of the doubles proves upon inspec

tion to be of extended application to the whole sub

ject. Examined for position these canals turn out to

have something to say for themselves bearing on the

question of their origin and office.

With regard to position, probably the first query to

suggest itself to an investigator to ask is of the direc

tion in which they run. Is there a preponderance mani

fest in them for one direction over another? Do they

show an inclination to the vertical, to the horizontal,
234 MARS AND ITS CANALS chap, xviii

or to some tilt between ? To answer this we may box

the compass, and taking the four cardinal points with

the twelve next most important points between for

sectional division segregate the doubles according to

their individual trend. As we have no means of deter

mining in which sense any direction is to be taken, — if

indeed it is not to be taken alternately in each, — we

get eight compartments into one or the other of which

all the doubles must fall. This they do in the following

manner : —

S. & N., Laestrygon, tFretum Anian, Aethiops, Amenthes,

Titan, tDis, tls 7

S. S. E. & N. N. W., tGihon, Ganges, {Tithonius, Euphrates,

Adamas 5

S. E. & N. W., tEunostos, Triton, Tartarus, Naarmalcha . 4

E. S. E. & W. N. W., tAstaboras, Typhon, tPierius . . 3

E. & W., tNar, tProtonilus, *Propontis, J Nectar, tCocytus,

t Chaos 6

E. X. E. & W. S. W. tDeuteronilus, tCallirrhoe, tCerberus N.,

Cerberus S., tSitacus, t Erebus 6

N. E. &penthes, S. W., tDjihoun, Gigas, tAlander, *Nilokeras Polyphemus, I & II, tAvernus, tGelbes, tMar- tNe

sias, tPyramus, tNildkeras I, Asopus . ... 12

N. N. E. & S. S. W., Jamuna, Phison, tHyblaeus, Cyclops,

Lethes, tThoth, tVexillum, tHiddekel ... 8

51

No conclusively marked preponderance for one direc

tion over another manifests itself by this partitionment. Nevertheless, a certain trend to the east of

* Wide canals. t Northern hemisphere exclusively.

J Southern hemisphere exclusively.
chap, xviii THE DOUBLE CANALS 235

north, as against the west of north, is discernible.

More than twice as many doubles run northeast and

southwest or within forty-five degrees of this as do

similarly northwest and southeast, there being twelve

of the latter and twenty-six of the former. That this

seems to mean something the nearly equal pairing of

quadrantal points goes to show. Thus : —

N. & S. and E. & W. inclined canals number . . 7 + 6 = 13

N. N. E. & S. S. W. and E. S. E. & W. N. W. in

clined canals number 8+3 = 11

N.number E. & S. W. and S. E. & N. W. inclined canals 12 + 4 = 16

E. N. E. & W. S. W. and N. N. W. & S. S. E. in

clined canals number 6 + 5 = 11

33 18 51

a fairly equable division in direction. A trend to the

westward would be given a particle descending from

the north to the equator by the planet's rotation, thus

turning it southwesterly; and one to the west to a

particle travelling equatorwards from the south, turn

ing it northwesterly. As the doubles lie in the northern

hemisphere, either in whole or part, to the extent of

93 %, this might account for the preponderating tilt to

the east of north and west of south exhibited by them.

It would correspond with the lines of flow.

To see whether this be so we will take only those

double canals that lie exclusively in the northern and

southern hemispheres respectively, and note those in
236 MAES AND ITS CANALS chap.xviii

the former that trend to the west of south as against

those that run to the east of it, and vice versa in the

southern. In the northern the proportion of the

westerly to the easterly ones is 17 to 4 ; in the southern,

1 to 0 the other way.

Of those whose course, is common to both hemispheres

we find for the ratio of the southwesterly to the south

easterly 8 to 7. But the proportion of the course of

these canals in the two hemispheres is on the side of

this same ratio.

From their direction we now pass to consideration

of their distribution in longitude. It appears that

some meridians are more favored than others. The

hemisphere which has the Syrtis Major for centre is

more prolific in them than its antipodes. From longi

tude 80° to 200° there are ten doubles, from 200° to

320° twenty-four, and from 320° to 80° seventeen ; or,

roughly, in the proportion of 2, 5, and 3. That

this distribution means anything by itself is doubtful;

it is much more likely to be a general topographical

consequence of their distribution in another direction,

which proves to be highly significant and which we

shall now expose — that of latitude.

If we separate the surface into zones, each ten degrees

wide, and count the doubles found traversing in whole

or part the several zones, we find the following arrange

ment : —
chap, xviii THE DOUBLE CANALS 237

Double Canals of Mars arranged according to latitude £ -

Between 30° S. and 20° S.

Between 20° S. and 10° S.

Between 10° S. and 0°

Between 0° and 10° N.

Tithonius, Nectar, Laestrygon

Jamuna, Ganges, Gigas,

Laestrygon, Cyclops,

Titan, Tartarus, Poly

phemus, Tithonius

Jamuna, Ganges, Gigas,

Laestrygon, Cyclops,

Cerberus S, Aethiops,

Lethes, Amenthes, Tri

ton, Phison, Euphra

tes, Titan, Tartarus,

illum, Adaas,Asopus, Typhon,Naar- Vex

malcha, Polyphemus . | 15 | 20

Gihon, Djihoun, Jamuna,

Ganges, Gigas, Laes

trygon, Cerberus N,

Cyclops, Cerberus S,

Eunostos, Aethiops,

Lethes, Amenthes, Tri

ton, Nepenthes, Phison,

Euphrates, Sitacus,

Hiddekel, Tartarus,

Adamas, Asopus, Ty

phon, Vexillum, Cocytus, Is, Avernus N,

Naarmalcha, Polyphe

mus . . . . | 21 I 29
238 MARS AND ITS CANALS chap, xvm

Dourle Canals of Mars arranged according to latitude

AtOpposition of

Alone 1903

Oppositions All observed sofar

Flagstaff a

Between 10° N. and 20° N. Gihon, Djihoun, Jamuna,

Nilokeras I and II,1

Nilokeras I, Ganges,

Gigas, Eunostos, Aethi

ops, Lethes, Amenthes,

Thoth, Astaboras, Phison, Si tacus, Euphrates,

Hiddekel, Adamas, Asopus, Gelbes, Avernus

N, Erebus, Naarmalcha,

Vexillum, Is, Dis 18 26

Between 20° N. and 30° N. Gihon, Djihoun, Jamuna,

Nilokeras I & II,1 Nilo

keras I, Alander, Hyblaeus, Lethes, Amen

thes, Thoth, Sitacus,

Astaboras, Vexillum,

Phison, Euphrates,

Hiddekel, Adamas,

Eunostos, Aethiops,

Gelbes, Avernus N,

Naarmalcha, Is . 17 23

Between 30° N. and 40° N. Deuteronilus, Alander,

Nar, Marsias, Fretum

Anian, Amenthes,

Thoth, Vexillum, Phison, Euphrates, Hidde

kel, Adamas, Eunostos,

Djihoun, Gihon, Nilo

keras I, Chaos, Gelbes,

Aethiops, Naarmalcha, 12 20

1 Very wide and possibly not of the same class.
chap, xviii THE DOUBLE CANALS 239

Double Canals of Mars arranged according to latitude

 

Between 40° N. and 50° N. Fretum Anian, Pyramus.

Protonilus, Propontis

Between 50° N. and 60° N. Callirrhoe, Fretum Anian,

Pierius

Between 60° N. and 63° N. Pierius, Callirrhoe . 2

3

3 3

2

4

From this tabulating of them it is apparent that the

doubles are practically confined to the zones within

forty degrees of the equator. Only 7 ft of them straggle

farther north than this, while above 63° north latitude

and 35° south latitude there are none. Such a distri

bution is not in proportion to the areas of the zones,

which though diminishing toward the poles do so

at no such rate. The surface included between the

equator and 40° of latitude is 65 ft of the hemisphere,

whereas the fraction of the number of doubles found

there is 93 ft. The doubles are, then, an equatorial

feature of the planet, confined to the tropic and tem

perate belts.

To perceive the tropical character of the doubles in

another way we have but to consider the zonal dis

tribution of the single canals. Unlike the former the

Very wide and possibly not of the same class.
240 MARS AND ITS CANALS chap, xvm

latter do not thin out as one advances toward the poles ;

since in the arctic regions single canals bemesh the sur

face as meticulously as elsewhere. It is only that they

there replace the doubles ; or, not to put the cart before

the horse, it is the doubles that in part replace the singles

in the tropics. And that this arrangement has some

thing physical behind it by way of cause is curiously

shown by two canals, the Arnon and the Kison, which

are neither of the one kind nor yet the other, but a

cross between the two. For the Arnon and the Kison

are convergent doubles; the two lines of the Kison

leaving a common point at the edge of the polar cap

and separating as they travel south, while the two

Arnon take up and continue the divergence, connect

ing at last with the parallel pair of the Euphrates.

These canals thus make transition between the true

doubles and the true singles, and may be looked upon

as endowed with the potentialities of both. From

their association with the double Euphrates, it is clear

that the transition between the two forms is not only

formal but physical, and that the stopping of the dual

condition at the fortieth parallel is not the outcome

of chance.

It may occur to the thoughtful that the doubles ap

pear confined to the more tropical portions of the planet

because of a better presentation of those zones, the

reader supposing the planet to be seen axised perpen
cap, xtiii THE DOUBLE CANALS 241

dicularly to the plane of sight, as geographies represent

the earth's globe. The supposition, however, is errone

ous. We sometimes see the planet so, but more often

not. Such is the tilt of the Martian axis to the plane

of the Martian ecliptic that the different zones are

rarely seen on an even keel, so to speak, their aspects

shifting totally from one opposition to another. What

shows in mid-disk on one occasion may be forty-eight

degrees removed from it at another, a distance

amounting to three-quarters of the way from apparent

equator to apparent pole.

Thus the double canals are for some intrinsic reason

equatorial features of the planet as opposed to polar

ones. And this not simply because of greater space

there. Duality is a result of conditions intrinsic to

the several localities. What the cause may be is re

lated to the character of the things themselves, which

we shall later consider. For the moment we may note

that the fact disposes quietly of the diplopic theory

of their manufacture. For, for diplopic doubles to

show such respect for the equator would betoken a

courtesy in them to be commended of Sydney Smith.

But this is not their only geographic bias. In addi

tion to not being partial to the poles, the double canals

show a certain exclusiveness toward the dark areas

generally. Not only do they avoid the arctic and ant

arctic zones entirely, but they largely shun the blueB
242 MARS AND ITS CANALS chap, xviii

green regions. In these but two suspicions of doubles

occur, in the Aonium Sinus, although single canals

there are as numerous as anywhere else on the planet.

Nevertheless, although they avoid running through

them, they run from them in a manner that is marked.

Proceeding from the great diaphragm are no less than

28 out of the 53 doubles. Connecting directly with

these are 17 more ; while the remaining 8 are also asso

ciated through the intermediarism of dark areas, the

Solis Lacus and the Trivium.

In like relation to dark regions, they are limited on

the north by the Mare Acidalium, the Propontis, the

Wedge of Casius and their interconnecting bands, the

Pierius, Callirrhoe, Helicon. In this manner do they

form a broad girdle round the planet's waist, leaving

the polar extremities bare.
CHAPTER XIX

CANALS IN THE DARK REGIONS

OEVENTEEN years after the recognition of the

canals in the light regions occurred another im

portant event, the discovery of a similar set in the dark

ones. The detection of these markings in the dark

areas was a more difficult feat than the perceiving of

those in the light, and in consequence was later accom

plished. Also was it one where recognition came by

degrees.

I have previously pointed out what this discovery

did for the seas — nothing less than the taking away

of their character in a generally convincing manner.

To one who had carefully considered the matter,

the seas had indeed already lost it, as was shown in

Chapter X, but to those who had not these canals

presented a very instant proof of the fact.

From such not wholly supererogatory service they

went on to furnish unlooked-for help in other directions.

Their discovery showed in the first place that no part

of the planet's surface was free from canal triangulation.

But it did more than this. For these canals in the

dark regions left the edge of the 'continents' at the

243
244 MARS AND ITS CANALS chap, xix

very points where the canals of the light regions entered

them, which fact proved for them a community of

interest with the latter. Such continuation was highly

significant, since it linked the two together into a single

system, compassing the whole surface of the planet.

Starting from the places where the light-region canals

come out upon the great girdle of seas that stretches all

round the planet, most of the new canals headed toward

the passes between the islands south, as nearly pole

wards as circumstances of local topography would per

mit. In the broader expanses of the Syrtis Major and

the Mare Erythraeum, besides main arteries others

went to spots in their midst after the same fashion

as those of the light regions. These spots differed in

no way apparently from their fellow oases elsewhere.

From a spot in the centre of the Syrtis three great lines

thus traveled south : the Dosaron, heading straight

up the Syrtis on the meridian till it struck the northern

most point of Hellas; the Orosines, inclined more to

the right, passing through the dark channel to the west

of that land and so proceeding south; and lastly the

Erymanthus turning eastward till it brought up finally

at the Hesperidum Lucus. Where, on the other hand,

the long chain of lighter land, called by Schiaparelli

islands, and stretching from the Solis Lacus region west

ward to Hellas, offered only here and there an exit,

the canals made for these exits. The canals in the Mare
chap, xix CANALS IN THE DARK REGIONS 245

Sirenum, the MareCimmerium, and the Mare Tyrrhenum

struck more or less diagonally across those seas from

their northern termini to the entrances of the straits

between the islands, thus lacing the seas in the way a

sail is rolled to its spar. From the exact manner in

which they connected with the light-region canals they

proved the two to be part and parcel of one system,

which in its extension was planet-wide and therefore

proportionately important. Whatever of strange inter

est the curious characteristics of the canals themselves

suggested was now greatly increased by this addition;

for the solidarity of the phenomenon affected the

cogency of any argument derived from it.

In 1894 only the dark areas of the southern hemi

sphere were found to be thus laced with lines. For then

so great was the tilt of the planet's south pole toward

the earth, that while those zones were well displayed

the dark patches of the northern hemisphere were more

or less hull-down over the disk's northern horizon.

Contrast was the open sesame to their detection.

When the maria show dark, the lines are lost in the

sombreness of the background. As the maria lighten

the lines come out. Such was amply witnessed by

the effect in 1894 and 1896. In 1894 I found it impos

sible to perceive them, except where the Padargus

crossed Atlantis, for the hue of the maria themselves

was then very dark. In 1896, on the other hand, I saw
246 MARS AND ITS CANALS C1HP. XIX

them without difficulty. What is also of interest: so

soon as seen they appeared small, without haziness

or distention.

As the oppositions succeeded one another the north

ern regions rose into view, and with their appearance

came the detection in them of the same phenomena.

No large dark areas like the diaphragm exist there, but

the smaller patches of blue-green which bestrew them

proved to be similarly meshed. At first canals were

evident upon their peripheries, contouring them about ;

then the bodies themselves of the patches showed gridironed by lines.

The Mare Acidalium with its adjuncts, the Lucus

Niliacus on the south and the Lacus Hyperboreus on

the north, thus stood out in 1901. On a particularly

good evening of definition at the end of May, the Mare

suddenly made background for a sunburst of dark rays,

six of them in all radiating from a point between it and

the Lacus Hyperboreus. Considering how sombre the

Mare was at the time, this was as remarkable a vision

as it was striking to see. Although at the moment

the sight was of the nature of a revelation, these lines

have been amply verified since, as the Martian season

has proved more propitious.

Similar decipherment has befallen all the other

patches of blue-green in the northern hemisphere;

these having shown themselves first circumscribed and
chap, xix CANALS IN THE DAKK REGIONS 247

then traversed by canals. Interesting instances were

the Wedge of Casius and the Propontis. These mark

ings, first perceived years ago as mere patches of shad

ing, then partially resolved by Schiaparelli, now stood

revealed as a perfect network of lines and spots. So

many of both kinds of their

detail occupied the ground

that to identify them all was

matter of exceeding difficulty.

The outcome is shown in the

diagrammatic representations

opposite and on page 256. The Propontis, wos.

These drawings disclose better than any description

the mass of detail of which the patches are in reality

composed, and serve to convey an idea of the com

plexity involved. If the general canal system seem

intricate, here is something which exceeds that as

much again.

The extension in this manner of the curious triangulation of the light areas into and through all the

dark areas as well, by thus spreading the field of its

operations over both terranes complexioned so unlike,

greatly increases the cogency of the deduction that this

detail is of later origin than the background upon which

it rests. That the mesh of lines covers not only the

ochre stretches of the disk, but the blue-green parts as

well, makes it still more certain that it is not a sim

 
248 MARS AND ITS CANALS chap, xix

pie physical outcome of the fundamental forces that

featured the planet's face. For in that case it could

not with such absolute impartiality involve both alike.

Thus here, again, we find corroboration by later ob

servations of what earlier ones established.

A last link in the chain of canal sequences remains

to be recorded. Just as the lines in the dark regions

continued those in the light, so they themselves turned

out to be similarly prolonged and in no less suggestive

a manner. For when the north polar zone came to be

displayed, canals were evident there, continuing those

in the other zones and running at their northern ends

into dark spots at the edge of the polar cap. Here,

then, we have the end of the whole system, or more

properly its origin, in the polar snows. The signifi

cance of this will be seen from other phenomena, to a

consideration of which we now proceed.
CHAPTER XX

OASES

EXT to be caught of the details of this most curi

ous network that meshes the surface of Mars was

a set of phenomena stranger even than the lines ; to wit,

dark round dots standing at their intersections. More

difficult to make out than the lines, they were in conse

quence detected thus later by fifteen years. Once

discovered, however, it became possible to trace their

unconscious recognition back in time. Thus Schiaparelli told the writer in 1895, apropos of those found at

Flagstaff, that he had himself suspected them but could

not make sure. Some of them stand figured in his

Memoria Seski dealing with the opposition of 1888, but

not published till 1899. In such posthumous recogni

tion, as one may call it, the spots repeated the history

of the canals. For Schiaparelli had himself pointed

out a similar preconscious visioning of the canals in

the delicate pencilings of Dawes and the streaks of

Lockyer, Kaiser, and Secchi, now translatable as rep

resenting the Phison, the Euphrates, and half a dozen

other canals imperfectly seen. That both the canals

and the oases were thus sketched before they were seen

 

249
250 MARS AND ITS CANALS chap, xx

well enough to be definitely discovered is to an un

prejudiced mind among their strongest credentials to

credit.

Nor was Schiaparelli the sole person thus to get proof

before letter. One of their very earliest portrayals

appears in a drawing by Otto Boeddicker, made on

December 26, 1881, where the Pseboas Lucus is clearly

represented. In a still more imperfect manner some

of the spots had been adumbrated and their shadows

drawn long before that. Thus they may be deciphered

as the cause of patches drawn by Dawes in 1864,

though none of them were in any definite sense de

tected till 1879, and only then so ill defined that their

true character was not apparent. As patches they are

still commonly seen at observatories where the obser

vational conditions are not of the best and the study

of the planet not systematically enough pursued to have

them disclose their true shape and size.

The history of their detection is resumed in the

experience of the individual observer. During the

course of my own observations I have had occasion to

notice the several stages in recognition of the spots

which have marked their chronologic career. As with

the lines, three stages in the appearance of the spots

may be remarked : first, where the scattering of the

rays is so wide that dilution prevents anything from

being seen; second, where the commotion being less
CHAP. XX OASES 251

the object appears as a gray patch; and third, where

in comparative quiet it condenses into a black dot.

For the two former our own air waves are to blame.

In coursing waves of condensation and rarefaction they

spread the image of the spot as they do that of the

canal. Then as the currents calm the spot shrinks

to its normal proportions, and in so doing darkens in

consequence of being less widely diffused. Thus the

evolution in perception which may take place in the

course of an hour for a particular observer represents

exactly what has occurred in the person of the race by

the improvement in observational methods and sites.

That the spots, although wider than the canals, re

mained longer hidden from human sight, is due to the

optico-physic fact that a tenuous line may be perceived

owing to its length when a dot of the same diameter

would be invisible. Summation of impressions is un

doubtedly the cause of this. The mere fact that a row

of retinal cones is struck, although each be but feebly

affected, is sufficient to raise the sum total into the

sphere of consciousness.

In the second stage of their visibility, the spots are in

danger of mistake with the smaller true patches of som

bre hue which fleck the northern hemisphere of the

planet and from which they differ totally in kind, totally

so far as our present perception goes. Such true

patches consist of a groundwork of shading, upon which,
252 MARS AND ITS CANALS chap, xx

indeed, are superposed the usual network of lines and

spots. Prominent as instances of them are the Trivium

Charontis, the Wedge of Casius, and the Mare Acidalium.

With patches of the sort the spots proper must not be

confounded.

Close treading on the heels of the detection of lines

athwart the seas came the recognition of spots there

likewise. At the opposition of 1896-1897 the num

ber was added to; and so the tale has been steadily

increased. Their number as found at Flagstaff up to

the present time, that is, to the close of the opposition

of 1905, is 186; of which 121 lie in the light regions,

42 in the dark areas of the southern hemisphere, and

23 in the smaller sombre patches of the northern zones.

From their relationships and behavior it became

apparent that the spots were not lakes but something

which answered much more nearly to oases.

Of the spots three kinds may be distinguished : the

large, the little, and the less, if by the latter term it may

be permitted to denote what has but collateral claim

to be included and yet demands a certain recognition.

For though not spots like the others, the members of

the third class have certain traits in common with them

while differing radically in others.

To the kind called large belong the greater number

of spots so far found upon the disk. They are large

only by comparison with the little. For they measure
CHAP. XX OASES 253

according to my latest determinations but seventyfive or one hundred miles in diameter ; on the planet

some two degrees across. Sizable black pin-heads,

it is their tone that chiefly catches the eye, for they

are commonly the darkest markings on the disk.

Against the ochre stretches they appear black, and

even in the midst of the dark areas they stand out

almost as much contrasted with their surroundings

as these do with the light regions themselves. About

a hundred and forty are now known. Those in the

light areas were discovered first; those in the dark

regions being harder to see.

Of this first kind are such spots as the Pseboas Lucus,

the Aquae Calidae,the Lacus Phoenicis, and the Novem

Viae; or, in English, the Grove of Pseboas, the Hot

Springs, the Phoenix Lake, and the Nine Ways, to men

tion no more. That they bear dissimilar names implies

no dissimilarity in structure. The phenomena are all

remarkably alike, and clearly betoken one and the

same class of objects; differing between themselves

at most in size and importance.

In form they all seem to be round. They certainly

appear so, and were it not that retinal images of small

areas tend to assume this shape might implicitly be

credited with being what they seem. The reason for

optical circularity probably resides in the shape of the

retinal cones and in their patterning into a mosaic
254 MARS AND ITS CANALS chap, xx

floor. So that unless a sufficient number of cones be

struck the image takes on to consciousness a roughly

circular figure — whether it be so in fact or not. In

the present case, however, they seem to be too well

seen for self-deception of the sort.

The little are distinguished from the large by being

pin-points instead of pin-heads. They are most mi

nute; from fifteen to twenty-five miles in diameter

only. That anything except size distinguishes the

two apart is from their look improbable. In color or

rather tone, — for distinctive color is of such minute

talis in Elysium in 1905, and the Gygaea Palus, besides

many more. These are all pin-points, just upon the

limit of vision, and noteworthy chiefly for being visible

at all. All those detected so far lie not very distant

from the equator, which may or may not be a matter of

accident. It is not one of perception, since this part

of the planet was not the best place for observation at

 objects unpredicable, —they

would seem to be alike.

Such is also the case with

association. their distribution and detail

 

To the second class be

long the Fons Juventae, —

Schiaparelli's Fountain of

Youth, — the Fons Immor
CHAP. XX OASES 255

the time they were discovered. To make out one of

these little dots is a peculiarly pleasing bit of observa

tion, as it requires particularly good definition. One

might almost take them for fly-specks upon the image

did they not move with the disk. They have no per

ceptible size and yet are clearly larger in diameter than

the canals which run into them; which proves how

very slender the latter must be.

Very early in the detection of the spots it became

evident that they were not scattered haphazard over

the surface, but that on the contrary they were never

found except at the meeting-points of the lines. From

this it must not be supposed, as has been done, that the

spots are merely optical reinforcements of the lines at

their crossings due to the more crowded character

there of the lines themselves. That they are not such

is demonstrated by the existence of crossings where,

either temporarily or permanently, none appear;

which shows that they are far too well seen for any

such illusion about them to be possible. At these cross

ings the lines traverse one another without thickening,

whether they be single or double lines. The spots,

on the other hand, are much wider than the lines,

giving a beaded look to the threads. In short, they

are the knots to the canal network. All the more im

portant junctions are characterized by their presence.

Such starred junctions are not confined to the ochre
256 MARS AND ITS CANALS CHAP. XX

regions; they dot the light and the dark areas with

equal impartiality, thus showing themselves to be in

dependent of the nature of the ground where large

stretches of country are concerned. On the other hand,

they appear to be unusually numerous in the smaller,

isolated, dark areas of the northern hemisphere, such

as the Trivium, the Mare Acidalium, the Propontis,

and the Wedge of Casius. Here they crowd ; and one

cannot avoid the inference that their plentifulness in

these regions is not due to chance.

To the large spots, those of the first class, fall the

places of intersection of the largest and most numer

ous canals, while the little spots make termini to

fainter lines, ones that bear to them a like ratio of un

importance. Spots and lines are thus connected not

simply in position but in size. The one is clearly

dependent on the other, the importance of the centre

being gauged by the magnitude of its communications.

 
CHAP. XX OASES 257

From the fact of association we now pass to the man

ner of it, which is quite as remarkable. The position

of the spot relative to its tributary canals depends upon

the character of the connecting lines. If the canal be

single it runs, so far as may be judged, straight into

the middle of the oasis, or, in other words, the oasis

is symmetrically disposed about its end. This is true

of the greater number of the large spots and of all the

little ones, since the latter have as connections only

single canals.

In the case of a double canal arriving at a spot, a differ

ent and most curious dependence is observable. This

fact I first noticed in a general way at the opposition of

1896-1897, the initial appearance of it being presented

on September 30, 1896, by the Coloe Palus and the

Phison. It was again visible in the case of the spots

in the Trivium at the time the canals leading to that

place doubled in March, 1897. But the exact nature

of the phenomenon was not fully appreciated till

1903, when the thing was seen so well as to appear

cut on copper plate. It was this: the spot is exactly

embraced between the two arms of the double canal.

It is, moreover, seemingly perfectly round and just

fits in between the parallel lines. The Ascraeus Lucus

was the first spot that showed thus in association with

the double Gigas. Others followed suit in so showing,

several specimens presenting themselves so well as to

s
MARS AND ITS CANALS CHAP. XX

leave no doubt of the precise connection. The sight

presented by such a spot and its incasing double is a

beautiful bit of detail, perhaps the most beautiful so

far to be seen upon the Martian disk. The distinct

ness with which it stands out on aoccasion steel engraving, suggests

/and shows how

clear-cut the Mar-

/ ^ tian features really

//-/sit**, *lucf are when our own

*a~v air ceases from

_? ,f,j. troubling and al

lows them to be

at rest. Incidentally, we may note that this phe

nomenon alone serves to disprove the diplopic theory

of the product ion of the double canals. For if a double

were a single line seen out of focus, any spot upon it

should be doubled too.

It may seem to the reader as if what was seen

in 1903 was but an unimportant advance over the

observed phenomena of 1890-1897. Not so, however.

For with the earlier instances it was not possible

to be sure of the precise limits of the spot with regard

to the double. The Coloe Palus, on the one hand, did

not fill all the space apparently between the double

Phison; while the Lucus Ismenius more than did so

with the double Euphrates. To have set down the
CHAP. XX OASES 259

different appearances to insufficient definition would

have been a great mistake, as subsequent observation

has served to show. The Lucus Ismenius instances

this. In 1896-1897 it was seen terminating the Eu

phrates, blocking all the space between the two lines

and extending a little upon either side of them. Now,

from its appearance in 1901 it was evident that the

effect had been produced by twin spots lying along

the Deuteronilus, the axis joining them being perpen

dicular to the Euphrates. In 1903 the relation was

still better explained by what appeared then, when not

only did the two spots stand out, but the Euphrates

showed with a line running centrally into each.

Although originally seen by Schiaparelli as a single

spot and so at first seen by me, better acquaintance

with the disk disclosed to both observers its really dual

character. As this pair has persisted through all three

of the most recent oppositions, it seems fairly certain

that it is always of this character, and more fitting,

therefore, to give it the plural appellative. This

is the single instance of a double oasis. There are

many that lie close together and might be taken as

such ; but this is the only one where the connection is

intrinsic. According to measures of the drawings of

1905 extending through six presentations, the distance

between the twin oases is 4°.2.

Their relation to the canals which run into them is of
260 MARS AND ITS CANALS chap, xx

the most complicated description and of the most sug

gestive character. For to the twin spots converge

no less than seven double canals, one wedge-shaped

pair and three single canals, a most goodly number of

communication lines. Four of the double canals run

into the oases with one line to each ; these canals are

the Astaboras, the Naarmalcha, the Euphrates, and the

Hiddekel. Three doubles, the Protonilus, the Djihoun,

and the Deuteronilus, embrace the oases between their

two lines, while, in the singles, the canal connects with

one or other of the twins, as the case may be.

Now, there is method as to which of the doubles

shall straddle, which embrace, the two Ismenii. Those

which leave the place parallel

or nearly so to the direction

joining the Luci, inclose

\ them both; those of which

the setting forth is at an

angle to this direction depart,

each line of the pair, from

the eastern and the western

Peculiar association of the Luci gpot respectively. Ismenii with double canals. Consider, now, the dispo

sition of these seven pairs of lines. All of them lie in

one semicircle about the Luci, beginning with the

Protonilus on the east and ending with the Deuter

onilus on the west. Furthermore, all follow approxi

 
CHAP. XX OASES 261

mately arcs of great circles, except the Djihoun, and

all send one of their twin lines to one Lucus, one to

the other. The data are enough to make this state

ment possible. Although the west line of the Naarmalcha has not been caught entering its oasis, the east

one has been seen to enter the other, and the width of

the double shows that the west one must enter the

corresponding spot. In the case of the Astaboras the

double has only been observed as far as the Vexillum, but the south line has continued on to the west

Ismenius, and here again the width makes it certain

that were the canal double throughout, the other line

must enter the east Ismenius. From the base line of

the Proto-Deuteronilus the inclinations of the seven

pairs are as follows : —

Protonilus

Astaboras

Naarmalcha

Euphrates

Hiddekel .

Djihoun .

Deutcrouilus

0° Due East

40° North of East

70° North of East

80° North of West

55° North of West

0° North of West

0° Due West

Now, the width between ,the t wo lines of the four canals

to the east increases regularly from the Protonilus

round ; the Protonilus being the narrowest double, the

Astaboras the next, the Naarmalcha the next, and the

Euphrates the widest. And from the width between

the twin oases, it would seem that they severally enter
262 MARS AND. ITS CANALS CHAP. XX

the centres of them. What takes place in the case of

the Hiddekel, which is wider than its tilt would imply,

common termini for all the canals of a given neigh

borhood. In other words, canals converge to the

places occupied by the spots and do not cross hap

hazard according to the laws of chance. Only one

instance exists where a spot fails to gather to itself

the whole sheaf of canals and even there it collects

all but two. This anomaly is the Pseboas Lucus.

The peculiarity of this oasis is that it lies not on,

but just off, the Protonilus. That it does .so is ex

ceeding curious, considering that it is the sole example

of such extra-canaline position. Strictly speaking, it is

not the Protonilus but the point where the Protonilus

turns into the Nilosyrtis to which it stands thus neighboringly aloof. And this may explain the anomaly.

For the Nilosyrtis has not the full geometric regu

larity of the normal canal, and seems to have been

a more or less fundamental feature of the region.

 

 

 

and in the Djihoun, which is

narrower, is not

so clear. But

that they enter

the oases in some

place is certain.

The spots make
CHAP. XX OASES 263

For the rest, the Lucus has the form and possesses

the canal connections appropriate to its state. It is

apparently round, and lies between the twin lines of the

Phison and also between those of the Vexillum.

Not far from the Pseboas Lucus are to be found all

the examples of the third class of spots ; for so far they

have not been observed outside of Aeria, a region pe

culiarly peopled by double canals. With double canals

they are necessarily associated, inasmuch as they con

sist of shading in the form of a square or parallelogram,

filling the deltas between two pairs that cross. Thus

have shown the Coloe Palus at the crossing of the double

Phison with the double Astaboras, and the Juturna

Fons where the double Sitacus traverses the double

Euphrates.

At these same places a fourth kind is sometimes no

ticeable : a four-square set of pin-points or a two-square

set of the same at the corners of the line -made parallelo

gram. This kind may well be synchronous with the

third, though it has only been noticed at consecutive

presentations. The third, however, has no observed

dependence upon the first or second classes. And this

serves to make more probable the true objectivity

of the circular and the square figures respectively

shown by each.

The spots apparent in the dark regions do not appre

ciably differ in either size or shape from the bulk of
264 MARS AND ITS CANALS CHAP. XX

those visible in the light. Equally with them they

seem to be round, small, and nearly black. They

would seem, too, in the great diaphragm — or larger

contiguous sombre region — to be equally plentifully

distributed.
CHAPTER XXI

CARETS ON THE BORDERS OF THE GREAT DIAPHRAGM

IUNCTIONALLY related to the canal system,

anil yet in look and location contrasted with its

other details, is a further set of markings, detected by

me in 1894, and reseen at subsequent oppositions

since, along the north border of the southern seas.

They lie upon what used to be thought the con

tinental coastline, the fringing edge of that almost

continuous band of shading that belts the Martian

globe throughout the southern subtropic zone and

called by Schiaparelli the great diaphragm. The terrane lends itself to the appellative, forming, as it does,

a dark dividing strip of country between the brilliant

reddish-ochre hemisphere on the north and the halftoned islands to the south of it. By Schiaparelli it

was thought to be one long Mediterranean, and though

its marine character is now disproved, that it lies

lower than the bright ochre regions is likely. To this

difference of level is probably due the peculiar phe

nomenon which there manifested itself to careful scru

tiny in 1894. For it was there only that it occurred.

The phenomenon in question consisted of nicks in

 

200
260 MARS AND ITS CANALS chap, xxi

the coastline, of triangular shape and filled with shad

ing. They occurred at intervals along it and were of

the general form of carets, such marks as one makes

in checking items down a list. Their position was al

ways where a canal debouched from the diaphragm

upon its career across the open continent. The canal

itself was by no means necessarily visible. On the

contrary, at first it was usually absent. Such was the

case with those marking the departure-points of the

Phison and Euphrates and of the Amenthes and

Lethes, which appeared, without being well defined,

from the moment the planet came to be scanned.

One by one these carets stood out to view, punctuating

the points where canals later were to show or termi

nating those that already existed. Strung thus with

them at intervals was the whole coastline of the dia

phragm, beginning with the Mare Icarium and stretch

ing round through the Mare Tyrrhenum, Mare Cimmerium, Mare Sirenum, and Mare Erythraeum to the

Mare Icarium again. As the planet got nearer to the

earth their peculiar shape began to define itself, and it

was again in the case of those giving origin to the Phison

and Euphrates that the recognition came first. What

had appeared earlier simply as a spot now stood out

as two triangular notches, indenting the coast and giving

exit at their apices, the eastern one to the Phison, the

western to the Euphrates. These were the things,
chap, xxi CARETS ON THE DIAPHRAGM 267

then, that had constituted the Portus Sigaeus of Schiaparelli.

Commonly the carets lie at the bottom of well-marked

bays, as, for example, those terminating the Syrtis

Minor and the Sinus Titanum. But frequently they

are placed in the very midst of a long and otherwise

unaccented coast, as is the case in mid-course of the

Mare Cimmerium and the Mare Sirenum. Yet in no

instance is the thing unassociated with a canal. In

every case one or more canals leave the caret for their

long traverse down the disk.

This is not their only canal connection. When the

canals in the dark regions came to be discovered, each

of them was found by me, as nearly as difficult obser

vations would permit, to be associated with the caret

upon its other side. Thus the lacing of the Mare Cim

merium and Sirenum used them as its reeving-points.

Similarly those at the mouths of the Phison and Eu

phrates did duty likewise to the Maesolus and the Ion.

In such manner the carets stood in dual relation to

canals ; subserving a purpose to the light-region canals

on the one hand and to the dark-region ones on the

other. In a way the caret, then, holds the same position

toward the canals that do the spots in the light or dark

regions. Like them it is a canal-distribution point.

Unlike them, however, in shape it is triangular instead

of round, and we are piqued to inquire to what cause
268 MARS AND ITS CANALS chap, xxi

it can owe its different contour. The answer seems to

lie in the character of the locality, not simply in its

complexion. For the spots in both the northern and

the southern dark patches are as circular as those stand

ing in the light, whether they lie in the centre or upon

the edges of them. The edges of the northern patches,

however, and the other sides of the southern ones do

not present the clear-cut character of the northern coast

of the diaphragm. Where they seem to be definitely

bounded they are so by darker canals. This hints

that their contours are not defined by antithesis of

level, while that of the northern coast of the great dia

phragm is. Difference of altitude is then concerned in

their constitution; the canal system here falls to a

lower level, and these triangular spots instead of round

ones are the result. Topographic only, such explana

tion leads the way to a more teleologic one, and serves

even on first acquaintance to stir curiosity to some

satisfying cause.

Suggestive in several ways for its resemblance to the

carets is another detail not far distant from the Portus

Sigaei, the twin-forked Sabaeus Sinus. Curiously

enough, this feature of Mars, which has been well

known and recognized ever since the eagle-eyed Dawes

detected it more than forty years ago, proves to be a

sort of connecting link between the main markings and

the details of more modern detection. The twin
chap, xxi CARETS ON THE DIAPHRAGM 269

forked Sabaeus Sinus, as its name implies, is of the

form of a double bay ; was considered to be one in fact

so long as the nutria were held to be seas. It straddles

the point of land which, called the Fastigium Aryn,

has been taken for the Greenwich of Martian longitudes.

Each 'bay' — not in truth a bay at all — indents

the ochre in an acute triangle, from the tip of which

many canals proceed like the rays of a fan from a hold

ing hand. Both tips are darker than the main body

of the dark mare from which they proceed. They thus

recall in general character the carets. They further

reproduce specifically the Portus Sigaei, for they give

origin to two doubles, the Gihon and the Hiddekel,

in exactly the same manner that the two nicks of the

Portus Sigaei do to the Phison and Euphrates. Nor

are their tips much farther apart than those of the

Portus, five degrees measuring the spread of the one

and four degrees that of the other respectively; the

reason for their earlier discovery lying in their greater

size. They thus perform the same office as the Portus

Sigaeus, are quite comparable to it in width, and differ

in shape only as a larger and more acute triangle differs

from a smaller and blunter one. Undreamt of by

Dawes and unheeded since, they were the first hint to

the world of the duality which forms so strangely per

vasive a feature of the canal system of the planet.

Thus the carets stand connected with the canals
270 MARS AND ITS CANALS chap, xxi

quite as intimately as the oases but in a significantly

different manner. For, in addition to their intermedi

ary standing between the light regions and the dark,

their relation to the doubles is peculiar. An instance is

offered by the double Euphrates and another by the

Ganges. The Euphrates, as we saw in Chapter XVIII,

leaves the Portus Sigaei at the south, one line leaving

each caret centrally, so that each caret is concerned only

with its own line and has no connection with its fellow.

At their northern ends both lines have similarly each

its own Lucus Ismenius. The like seems to be true of

the Ganges. Similarly the twin Titan, have each its

own. Such twin duty in the matter of doubles seems

to be the rule with the carets, even more so than with

the oases; and this is probably from the fact that the

coastline is of more limited extent than the interior.

Altogether the carets offer to our inspection glosses

in finer print upon the general text of the canals.

Thought upon what they show takes us a step farther

toward the solution of the strange riddle of this other

world, a riddle which he who runs may not read, still

less scout, and which only reasoning, without prejudice

or partiality, can unravel.
CHAPTER XXII

THE CANALS PHOTOGRAPHED

pHOTOGRAPHY holds to-day a place of publicity

in the exposition of the stars. Directed by Draper

to the heavens thirty-four years ago, the camera re

corded then the first picture ever taken of the moon.

From this initial peering into celestial matters, practice

has progressed until now the dry plate constitutes one

of the most formidable engines in astronomic research.

Not most effectively, however, in the field which might

have been predicted. Beautiful as the lunar present

ment was, as a presentiment of what was coming, it

pointed astray. For it is not in lunar portrayal, su

perbly as its crater walls in crescent chiaroscuro or its

crags that cast their tapering shadows athwart the dial

of its plains stand out in the latest photographs of our

satellite, that the camera's greatest service has since

been done. Impressive as they are, these pictorial

triumphs are chiefly popular, and appeal on their face

to layman and scientist alike. Not in the nearest to

us of the orbs of heaven, but in the most remote has

celestial photography's most prolific field been found

to lie. Its province has proved preeminently the stars,

271
272 MARS AND ITS CANALS CHAP. XXII

especially the farthest off, and that star-dust, the

nebula3, from out of which the stars are made. Reason

for this explains at once its efficiency and its limitations.

Its rival, of course, is the eye. It is as regards the

eye that its comparative merits or demerits stand to

be judged. Now, thus viewed, its superiority in one

respect is unquestionable; it simply states facts.

But though it cannot misinform, it can color its facts

by giving undue prominence to the effect of some rays

and suppressing the evidence of others, so that its

testimony is not, it must be remembered, always in

accord with that of human vision. Speaking broadly,

however, it is so little complicated a machine as to

register its results with more precision than the retina.

The evidence of the camera has thus one important

advantage over other astronomic documents : it is im

personally trustworthy in what it states. Bias it has

none, and its mistakes are few. Imperfections, indeed,

affect it, but they are of purely physical occasion and

may be eliminated or accounted for as well by another

as by the photographer himself.

In trustworthiness, then, so far as it goes, it stands

commended; not so much may be said of its ability.

This depends upon the work to which it is put. In cer

tain lines it asserts preeminence ; in certain others it is

so far behind as to be out of the race. The reason for

both is one and the same, for, as the French would
chap, xx,. THE CANALS PHOTOGRAPHED 273

say : It has the faults of its quality. The very trait

that fits it for one function, bars it from the other.

This excellence is that by which the tortoise outstripped

the hare, —a plodding perseverance. Far less sensitive

than the retina the dry plate has one advantage over its

rival, —its action is cumulative. The eye sees all it can

in the twentieth of a second ; after that its perception,

instead of increasing, is dulled, and no amount of

application will result in adding more. With the dry

plate it is the reverse. Time works for, not against it.

Within limits, themselves long, light affects it through

out the period it stands exposed and, roughly speaking,

in direct ratio to the time elapsed. Thus the camera

is able to record stars no human eye has ever caught

and to register the structure of nebulae the eye tries to

resolve in vain.

Where illumination alone is concerned the camera

reigns supreme; not so when it comes to a question

of definition. Then by its speed and agility the eye

steps into its place, for the atmosphere is not the

void it could be wished, through which the light-waves

shoot at will. Pulsing athwart it are air-waves of

condensation and rarefaction that now obstruct, now

further, the passage of the ray. By the nimbleness of its

action the eye cunningly contrives to catch the good

moments among the poor and carry their message to the

brain. The dry plate by its slowness is impotent to

T
274 MARS AND ITS CANALS chap, mi

follow. To register anything, it must take the bad with

the better to a complete confusion of detail. For the

air-waves throw the image first to one place and then

to another, to a blotting of both.

All of which renders the stars, where lighting counts

for so much and form for so little, the peculiar province

of celestial photography. With the study of the sur

faces of the planets the exact contrary is the case. With

most of them illumination is already to be had in

abundance ; definition it is that is desired. What suc

ceeds so excellently with the stars is here put to it to

do anything at all. At its best, the camera is hopelessly

behind the eye when it comes to the decipherment of

planetary detail. To say that the eye is ten times the

more perceptive is not to overstep the mark. To try,

therefore, here to supplant the eye by the camera

is time thrown away.

Of scant importance to the expert in such matters as

Mars, there is a side of the subject in which service

might be hoped of it : that of elementary exposition.

Congenitally incapable of competing with the eye in

discovery, the most that, by any possibility, could be

looked for would be a recording of the coarser details

after the fact. For this reason it had long been a

purpose at Flagstaff to photograph some at least of

the canals. But the project seemed chimerical. To

get an image suitable at all some seconds of exposure
chap, xxh THE CANALS PHOTOGRAPHED 275

would be required, and during such time the shifting

air-waves would blur the very detail desired to be got.

It was a problem of essential premises mutually annihilative. The more the would-be photographer should

avoid Nevertheless the one, the the more thing hewaswould triedfallin 1901. into theInother. 1903

the subject was taken up by Mr. Lampland, then new

at the observatory. The results were better than

those of two years before, the images more clear-cut

but still incommunicable of canals. Still they were

satisfactory enough to spur to increased endeavor, and

during the following interopposition preparations were

made to grapple with the planet as successfully as could

be devised at its next return. This happened in

May, 1905. It then showed a disk only 17" in diam

eter, or of that of the moon, — and this disk Mr.

Lampland attacked with the 24-inch and a nega

tive amplificator that increased the focal length of the

former to 143 feet. At such focus the planet's image

was received upon the plate. Everything that could

conduce to success had been put in requisition. To

this end of better definition the color curve of the ob

jective was first got, and for it a special color screen

constructed by Wallace. In spite of its name no achro

matic is so in fact, but brings rays of different tint to

different focus. The color curve shows where these

severally lie, and the color screen, a chemically tinted
276 MARS AND ITS CANALS CHAP. XXII

piece of glass, is to absorb all those which would blur

the image by having a different focus from the ones re

tained. Xext, all manner of plates were tried. For

in these again it was necessary to reconcile two con

tradictory characters, a rapid plate and a welldefining one. For the coarser the grain the speedier

the plate; and coarse grain disfigures the detail.

Both qualities on so small an image were obligatory

and yet both could not be got. Then the clock

had to be as smooth-running as possible. So by a sug

gestion of Mr. Cogshall's one was obtained that filled

this requisite, a new form of conical pendulum. Upon

this a further refinement was practiced. Ordinarily

clockwork is timed to follow the stars ; this was altered

to follow the planet, and so keep it more nearly mo

tionless while its picture was being taken. Then the

device of capping down the telescope to suit the air

waves, which had been found so effective to the bringing

out of fine detail, was put in practice. Lastly, all de

velopers were tried, and those found suited to the

finest work were used.

Many pictures were taken on each plate one after

the other, both to vary the exposure and to catch such

good moments as might chance. Seven hundred images

were thus got in all ; the days of best definition alone

being utilized. The eagerness with which the first

plate was scanned as it emerged from its last bath may
chap, xxn THE CANALS PHOTOGRAPHED 277

be imagined, and the joy when on it some of the canals

could certainly be seen. There were the old configura

tions of patches, the light areas and the dark, just

as they looked through the telescope, and never till

then otherwise seen of human eye, and there more mar

velous yet were the grosser of those lines that had so

piqued human curiosity, the canals of Mars. He who

ran might now read, so that he had some acquaintance

with photography. By Mr. Lampland's thought, as

siduity, and skill, the seemingly impossible had been

done.

After the initial success was thus assured, plates were

taken at other points around the planet and other wellknown features came out; "continents" and "seas,"

"canals" and "oases," the curious geography of the

planet printed for the first time by itself in black and

white. By chance on one of the plates a temporal

event was found registered too, the first snowfall of the

season, the beginning of the new polar cap, seen visually

just before the plate happened to be put in and repro

duced by it unmistakably. Upon the many images

thirty-eight canals were counted in all, and one of them,

the Nilokeras, double. Thus did the canals at last

speak for their own reality themselves.

THE CANALS PART INIIIACTION

CHAPTER XXIII

canals: kinematic

GO far in our account of the phenomena we have

regarded the lines, the spots, and everything that

is theirs solely from the point of view of their appearance

at any one time. In other words, we have viewed

them only from a static standpoint. In this we have

followed the course of the facts, since in this way were

the canals first observed. We now come to a different

phase of the matter, —the important disclosure, with

continued looking, that these strange things show them

selves to be subject to change. That is, they take

on a kinematic character. This at once opens a fresh

field of inquiry concerning them and widens the horizon

of research. It increases the complexity of the prob

lem, but at the same time makes it more determinate.

For while it greatly augments the number of facts

which must be collected toward an explanation of

what the things are, these once acquired, it narrows

the solution which can apply to them.

The fact of change in the Martian markings forces

itself upon any one who will diligently study the planet.

He will be inclined at first to attribute it to observa281
282 MARS AND ITS CANALS chap, xxm

tional mistakes of his own or his predecessor's making,

preferably the latter. But eventually his own delinea

tions will prove irreconcilable with one another, and

he will then realize the injustice of his inference and

will put the cause, where indeed it rightly belongs, on

the things themselves. Confronted by this fact he will

the more fully appreciate how long and systematic

must be the study of him who would penetrate the

planet's peculiarity. Just as the recognition of some

thing akin to seasonal change came to Schiaparelli, be

cause of his attending to the planet with an assiduity

unknown to his predecessors; so it became evident

that to learn the laws of these changes and from

them the meaning of the markings, there was necessary

as full and as continuous a record of them as it was pos

sible to obtain. For this end it was not enough to get

observations from time to time, however good these

might be, but to secure as nearly as might be a complete

succession of such, day after day, month after month,

and opposition after opposition. The outcome justified

the deduction. And it is specially gratifying to realize

that to no one have the method and the results thus

obtained appealed with more force than to Schiaparelli

himself.

Perseverance in scanning the disk long after the

casual observer had considered it too far away for

observational purposes, resulted in Schiaparelli's detec
chap, xxiii CANALS: KINEMATIC 283

tion of the canals, and this through a characteristic

of theirs destined to play a great part in their history,

their susceptibility to change. He tells us in his Memoria I how Aeria and the adjoining regions showed

blank of any markings while the planet was near in 1877

and the disk large and well shown, and then how, to his

surprise, as the planet got farther away and the disk

shrank, lines began to come out in the region with un

mistakable certainty. Thus to the very variability

which had hidden them to others was due in Schiaparelli's hands their initial recognition.

Flux affecting the canals was apparent from the

outset of my own observations. No less the subject

of transformation than the large dark regions was the

network of tenuous lines that overspread them. At

times they were very hard to make out, and then again

they were comparatively easy. Distance, instead

of rendering them more difficult, frequently did the

reverse. Nor was the matter one of veiling. Neither

our own atmosphere nor that of Mars showed itself

in any way responsible for their temporary disappear

ance. It was not always when our atmospheric con

ditions were best that the lines stood out most clearly,

and as to Martian meteorology there was no sign that

it had anything whatever to do with the obliteration.

Long before the canals were dreamt of, veiling by

Martian clouds or mist had been considered the cause
284 MARS AND ITS CANALS chap, xxm

of those changes in the planet's general features, which

are too extensive and deep-toned wholly to escape ob

servation even though none too clearly seen. It was

early evident to me that they were not the cause of

general topographic change, and equally clearly as

inoperative in those that affected the canals. In short,

nothing extrinsic to the canal caused its disappearance ;

whatever the change was, its action lay intrinsic to the

canal itself.

On occasion canals in whole regions appeared to be

blotted out. The most careful scrutiny would fail

to disclose them, where some time before they had been

perfectly clear. And this though distance was at its

minimum and definition at its best. Even the strongest

marked of the strange pencil lines would show at times

only as ghosts of their former selves, while for their more

delicate companions it taxed one's faith to believe that

they could ever really have existed. Illumination

was invoked to account for this, and plays a part in the

effect undoubtedly. For at plumb opposition the cen

tre of the disk for two or three years has shown less

detail than before and after that event. This is prob

ably due not, as with the moon, to the withdrawal of

shadows, but to the greater glare to which the disk

is then subjected. But this is not the chief cause of

the change.

Still more striking and unaccountable was the fact
chap, xxiii CANALS: KINEMATIC 285

that each canal had its own times and seasons for show

ing or remaining hid. Each had its entrances upon the

scene and its exits from it.

What dated the one left

another unaffected. The

Nilokeras was to be seen

when the Chrysorrhoas was

invisible, and the Jamuna

perfectly evident when the

made Indus OUtcould scarcely be Showing seasonal change.

I. So much shows in the two

Ganges drawingsandherethereproduced. advent of The the Chrysorrhoas increase of the ar

noticeable in the second

overSeasonal the first. changes seemed

the only thing to account

for the phenomena. And in

a general sense this was

undoubtedly the explana

tion. To learn more about

Showing seasonal change. tne matter, to verify it if it II. '

it if possible, I determinedexisted, to undertake and to anparticularize investiga

tion permitting of quantitative precision in the case.

A method of doing this occurred to me which would

 

 
286 MARS AND ITS CANALS chap, xxiii

yield results deserving of consideration from the amount

of data upon which each was based and capable

of being compared with one another upon an equal

footing from which relative information could be de

rived. It seemed wise to determine from the draw

ings the degree of visibility of a given canal at

different seasons of the Martian year, and then to do

this for every important canal during the same period

of time. The great number of the drawings suggested

this use to which they might be put. For from a great

accumulation of data a set of statistics on the subject

could be secured in which accident or bias would be

largely eliminated and the telling effect of averages

make itself felt.

To render this possible it was necessary that the

drawings should be alike numerous, consecutive, and

extended in time. These conditions were fulfilled by

the drawings made by me at the opposition of 1903.

Three hundred and seventy-two drawings had then

been secured, and they covered between them a period

of six months and a half. They were also as consecu

tive as it was possible to secure. During a part of the

period the planet was seen and drawn at every twentyfour hours, from April 5, namely, to May 26, or for fortysix consecutive days. Though the rest of the time did

not equal this perfection, no great gap occurred, and

one hundred and forty-three nights were utilized in all.
chap, xxm CANALS: KINEMATIC 287

Furthermore, as these drawings were all made by one

man, the personal equation of the observer —a very

important source of deviation where drawings are to

be compared — was eliminated.

But even this does not give an idea of the mass of

the data. For by the method employed about

100 drawings were used in the case of each canal,

and as 109 canals were examined this gave 10,900

separate determinations upon which the ultimate

result depended. That each of these determinations

was independent of the others will appear from a

description of the method itself on which the investiga

tion was conducted. To understand that method one

must begin a little way back.

As the two planets, Mars and the Earth, turn on their

axes the parts of their surfaces they present to each

other are constantly changing. For a feature on Mars

to be visible from a given post on earth, observer and

observed must confront each other, and, furthermore,

it must be day there when it is night here. But, as

Mars takes about forty minutes longer to turn than the

Earth, such confronting occurs later and later each

night by about forty minutes, until finally it does not

occur at all while Mars is suitably above the horizon;

then the feature passes from sight to remain hidden

till the difference of the rotations brings it round into

view again. There are thus times when a given region
288 MARS AND ITS CANALS chap, xxiii

is visible, times when it is not, and these succeed each

other in from five to six weeks, and are called presenta

tions. For about a fortnight at each presentation a

region is centrally enough placed to be well seen; for

the rest of the period either ill-placed or on the other

side of the planet.

If a marking were always salient enough it would

appear in every drawing made of the disk during the

recurrent fortnights of its display. If it were weaker

than this, it might appear on some drawings and not on

others, dependent upon its own strength and upon the

definition at the moment, and we should have a certain

percentage of visibility for it at that presentation.

While if it changed in strength between one presentation

and the next, the percentage of its recording would

change likewise. Definition of course is always vary

ing, but if its value be noted at the time of each draw

ing this factor may be allowed for more or less success

fully. Making such allowance, together with other

corrections to produce extrinsic equality, such as the

planet's distance, which we need not enter upon here,

we are left with only the marking's intrinsic visibility

to affect the percentages ; that is, the percentages tell

of the changes it has successively undergone and give

us a history of its wax and wane.

From drawings accurately made it is possible to add

to the accuracy of the percentage by noting in each,
chap, xxiii CANALS : KINEMATIC 289

not only the presence or absence of the marking, but

the degree of strength with which it is represented.

This was done on the final investigation in the present

case, and it was interesting to note how little difference

it made in the result.

The longitude of each canal was known, and the

longitude of the central meridian of each drawing was

always calculated and tabulated with the drawing, so

that it was possible to tell which drawings might have

shown the canal. Only when the position of the canal

was within a certain number of degrees of the centre

of the drawing (60°) was the drawing used in the

result, allowance being duly made for the loss upon the

phase side. Each drawing, it should be remembered,

was as nearly an instantaneous picture of the disk as

possible. It covered only a few minutes of observa

tion, and was made practically as if the observer had

never seen the planet before. In other words, the

man was sunk in the manner. Such mental effacement

is as vital to good observation as mental assertion is

afterward to pregnant reasoning. For a man should

be a machine in collecting his data, a mind in coordi

nating them. To reverse the process, as is sometimes

done, is not conducive to science.

When the successive true percentages of visibility

of a given canal had thus been found, they were plotted

vertically at points along a horizontal line correspondD
290 MARS AND ITS CANALS CHAP. XXIII

ing in distance from the origin to the number of days

after (or before) the summer solstice of the Martian

northern hemisphere. The horizontal distance thus

measured the time while the vertical height gave the

relative visibility. The points so plotted were then

joined by a smooth curve. This curve reproduced the

continuous change in visibility undergone by the canal

during the period under observation. It gave a

graphic picture of the canal's change of state. It

seemed, therefore, proper to call it the canal's cartouche

or sign manual.

In this manner were obtained the cartouches of 109

canals. Now, as the presence or absence of any canal

in any drawing was entirely irrespective of the

presence or absence of another, each such datum

spoke only for itself, and was an entirely independent

observation. The whole investigation thus rested on

10,900 completely separate determinations, each as

unconditioned by the others as if it existed alone.

As every factor outside of the canal itself which could

affect the latter's visibility was taken account of, and

the correction due to it as nearly as possible applied

before the cartouches were deduced, the latter repre

sent the visibility of the canal due to intrinsic change

alone. In other words, they give not the apparent only

but the real history of the canal for the period con

cerned.
chaf.xxiii CANALS: KINEMATIC 291

Important disclosures result from inspection of the

cartouches. This we shall perceive by considering what

different curves mean in the case. If the canal were

an unchangeable phenomenon, for any reason what

ever, its cartouche would be a straight line parallel to

the horizon of the diagram. This is evident from the

fact that the visibility would then never vary. If,

on the other hand, it were waxing and waning, and the

wax or wane were uniform, the cartouche would be a

straight line inclined to the horizontal; rising if the

canal were increasing, falling when it decreased.

Lastly, if the rate of change itself varied, the cartouche

would be a curve concave or convex to the line denot

ing the time, according as the rate of change of the

growth or decay grew greater or less.

To see this the more clearly, we may set over against

the cartouche the canal character it signalizes : —

Cartouche. Character.

A curved straight straight horizontal line linestraight descending, tilted upuline.onoconcave the the right. left.from Canal Canaldecreasing, invariable. decreasing increasing but steadily. steadily. more

A above. curved line ascending, concave from Canal andincreasing, more slowly.but more

A above. curved line descending, convex from Canal anddecreasing more rapidly. more and

A above. curved line ascending, convex from Canal moreincreasing rapidly. more and ■

above. more slowly.
2i»2 MARS AND ITS CANALS CHAP. XXIII

Cartouche. Character.

A curved line first descending, then Canal decreasing more and

A curved line first descending, then Canal increasing more and

If the cartouche first falls and then rises, this shows

the canal to have passed through a minimum state at

the time denoted by the point of inflection; if it rises

first and falls afterward, this betokens in the same way

a maximum. Thus the cartouches reveal to us the

complete history of the canals, — what changes they

underwent and the times at which these occurred.

The cartouche, then, is the graphic portrayal of the

canal's behavior. It not only distinguishes at once

between the dead and the living, as we may call the

effect of intrinsic change, but it tells the exact character

of this change, —the way it varied from time to time,

the e{x,ch at which the development was at its minimum

or its maximum for any given canal, and lastly, its

actual strength at any time, thus giving its relative

importance in the canal system. For the height of the

curve alx,ve the diagrammatic horizon marks the abso

lute as well as the relative visibility and enables us to

rank the canals between themselves.

Now. the first point it furnishes a criterion for is the

ascending, concave from above

throughout.

more slowly to a mini

mum, thence increasing

more and more rapidly.

ascending, convex from above

throughout.

more slowly to a maxi

mum, thence decreasing

more and more rapidly.
CHAP. XXIII CANALS : KINEMATIC 293

real or illusory character of the canals. If a line be due

to illusion, whether optical or physical, it can vary only

from extrinsic cause, since it has no intrinsic existence.

If, therefore, all extrinsic cause be allowed for, the car

touche of this ghost must needs be a horizontal straight

line. Even if the extrinsic factors to its production

be imperfectly accounted for, their retention could only

cause systematic variations from the straight line in all

the lines, which would themselves vary systematically,

and these factors could therefore be detected.

This criterion is absolute. Unless all the cartouches

were approximately straight lines, no illusion theory

of any kind whatever could explain the facts. Even

then the lines might all be real ; for unchangeable reality

would produce the same effect on the cartouches as illu

sion. In the case therefore of horizontal straight line

cartouches, we should have no guarantee on that score

of reality or illusion ; but, on the other hand, curves or

inclined straight lines in them would be instantly fatal

to all illusion theories.

Turning now to the 109 cartouches obtained in 1903,

the first point to strike one's notice is that all but three

accepted of them are withcurves a caveat.nd that Here,even then,these the cartouches three mustdisbe i

pose once and for all of any and every illusion-theory. '

They show conclusively that the canals are real objects

which wax and wane from some intrinsic cause.
294 MAES AND ITS CANALS chap, xxiii

The second result afforded by the cartouches is not of

a destructive, negative character, — however valuable

the destruction of bars to knowledge may be, — but of

a constructive, positive one. It does not, like the first,

follow from mere inspection, but is brought to light only

by comparison of all the cartouches. In a positive way,

therefore, its testimony is as conclusive as it was in a neg

ative direction. For that 10,900 separate and independ

ent data should result in a general law of development

through either conscious or unconscious bias, when those

data would have to be combined in so complicated a

manner for the result to emerge as is here the case, is

impossible. Chance could not do it and consciousness

would require a coordinate memory, to which Murphy's

nine games of chess at once would be child's play.

Of the 109 canals examined 106 showed by their car

touches that they had been during the whole or a part

of the period in a state of change. But the change

was not the same for all. In some the minimum came

early ; in others, late. Some decreased to nothing and

stayed there; others increased from zero and were

increasing still at the time observations closed.

Latitude proved the means of bringing comparative

order out of the chaos. When the canals were ranged

according to their latitude on the planet, a law in their

development came to light. To understand it, the

circumstances under which the canals were presented
CHAP. XXIII CANALS: KINEMATIC 295

must be considered as regards the then season of

the planet's year. In 1903 the planet passed on

February 28 through the point of its orbit where the

summer solstice of the northern hemisphere occurs.

One hundred and twenty-six days later took place the

first snowfall in the arctic and subarctic regions, an

event that denoted the beginning of the new polar cap ;

from which date the snow there gradually increased.

Its autumnal equinox the planet did not reach till

August 29. Now, the canals were observed from thirtysix days before the summer solstice of the northern

hemisphere to one hundred and forty-seven days after

that event. We may tabulate the dates as follows : —

Day from Summer Solstice Vehxai. Longitude Corresponding Date on Earth

-30 77° June 9

0 90° June 22

+ 30 103° July 6

+ 60 117° July 20

+ 90 131° August 4

+ 120 146° August 20

+ 150 162° September 5

The vernal longitude is the longitude of the planet

in its orbit reckoned from the vernal equinox. From

the table it appears that the cartouches cover the de

velopment of the canals from about June 6 to September

1 of the Martian northern hemisphere for the current

but to us undated year, ab Marie condita.
296 MARS AND ITS CANALS chap,xxiii

The 109 canals included all the more conspicuous

canals on the planet at that opposition, all those

that lent themselves by the sufficient frequency

with which they were seen to a statistical result.

They lay spread all the way between the edge of

the polar cap in latitude 87° north to the extreme

limit south, at which the then tilt of the north pole

toward the earth permitted of canal recognition.

This southern limit was in about latitude 35° south.

Farther south than this vision became too oblique,

amounting as it did, with an adverse tilt of twentyfive degrees to start with, to something over sixty

degrees, for detection of such fine markings to be

possible. Between the two limits thus imposed, by

the perpetual snow on the one side and the ob

servational tilt on the other, the 109 canals were

distributed by zones as follows : —

Zone Latitude Number of Canals

North Polar 87° N.-78° N. 1

Arctic 78° X.-660 N. 9

Sub-Arctic 66° N.-51° N. 9

North Temperate 51° N.-37° N. 11

North Sub-Tropic 37° N.-24° X. 18

North Tropic 24° N.-120 N. 21

North Equatorial 12° N.- 0° N. 14

South Equatorial 0° N.-12° S. 17

South Tropic 12° S.-24°S. 7

South Sub-Tropic 24° S.-37JS. 2
chap, xxiii CANALS: KINEMATIC 297

As the latitude of a canal in the investigation was

taken as that of its mid-point, such being the mean

value of its successive parts, the latitudes about which

information was obtained lay within the limits given

above, the most northern canal, the Jaxartes N having

for its mid-latitude 78° north, and the most southern,

the Nectar, that of 27° south.

The zones comprised each a belt of territory about

thirteen degrees wide, the first being less solely because

in part occupied by the permanent polar cap.

The curves of all the canals in a given zone have been

combined into a mean curve or cartouche for that

zone; and then the cartouches for the several zones

have been represented and ranged according to lati

tude on the accompanying plate. Consideration of

these mean canal cartouches is very instructive. In

the first place not one of them is a straight line, either

horizontal or inclined. All are curves and, with the

exception of the top one, all show a minimum or lowest

point during the period under observation. From this

point they rise with the time, or to the right on the

plate. A black star marks this minimum, and is found

farther and farther to the right as one goes down the

plate ; that is, as one travels from the neighborhood of

the arctic regions down to the equator and then over

into the planet's southern hemisphere. Drawing now

a line approximately through the stars and remembering
298 MAES AND ITS CANALS chap, xim

 
chap, xxiii CANALS : KINEMATIC 299

that the minimum means the date at which the canal

started to develop, we see that the canal development

began at the border of the north polar cap and thence

continued down the disk over the planet's surface, as

far as observation permitted the surface to be seen,

which was some thirty-five degrees into the other hemi

sphere. This is the first broad fact disclosed by the

cartouches.

Furthermore, the development took place at an

approximately uniform rate. This is shown by the

fact that the line passing through the black stars is

approximately straight; for such straightness means

that progression down the disk as measured by the

latitude bore throughout the same ratio to the time

elapsed.

Looking at them again we notice that the three top

most cartouches, those of the north polar, arctic, and

sub-arctic canals respectively, dip at the right before

the end of the observations, while the other seven were

still rising when those observations were brought to a

close. A reason for this, or at least a significant coin

cidence, is to be found in the dotted line pendent from

the top of the table and labelled "First Frosts." This

dotted line denotes the date at which the first extensive

frost occurred in the polar regions; for even before

this time patches of white had appeared north of the

Mare Acidalium, denoting the on-coming of the cold.
300 MARS AND ITS CANALS chap, xxiii

The frost did not last but came and went and came

again just as it does on earth, growing more insistent

and long-lived at each fresh fall. Its sphere of opera

tion was confined to the three zones in question.

Even these zones it by no means covered, merely

blotching them in places with fungi-like patches of frost.

Beyond them south it never extended during the period

of the observations ; indeed, it hardly entered the sub

arctic zone at all at this very beginning of the polar

winter. For it was only August 20 then. The coin

cidence of the isotherm as betrayed by the deposition

of frost with the dividing line between the canaldevelopment curves that dip down at this season and

those that still continue to rise is suggestive.

It becomes all the more so when the three cartouches

are considered seriatim. The most polewards, the

north polar one, had sunk to zero sometime before the

first extensive frost occurred; the second, the arctic,

did so later than its northern neighbor, probably just

before the epoch in question; while the third, prac

tically outside the zone of deposition, was behind both

the others in its descent. Inspection of the drawings

upon which the cartouches are based confirms an infer

ence deduced from this : that it was cold that killed,

not frost that covered, them, which was responsible

for their obliteration. The drawings show that the

canals ceased to be seen before the white patches were
chap, xxiii CANALS: KINEMATIC 301

evident. Now this would be the exact behavior of

vegetation. It would be killed, turned brown by

freezing, and so rendered invisible to us against its

ochre desert background, before the cold had grown

intense enough to cover that ground with a solid white

carpet of frost. At the opposition of 1905, however,

the extreme northern canals were visible after the snow

had covered all the country about them, being evident

as lines threading the new cap.

These three cartouches furthermore show each a

maximum, and what is significant the maximum occurs

later in time for each, according as the zone lies remote

from the pole. A red star marks this maximum and

shows that the time of greatest development for the

three zones was respectively : —

41695 days after the t summer solstice solstice solstice for the Sub-Arctic. North Arctic.Polar.

We now pass to the other curves, those that were

unaffected by cold. Though in these the minima them

selves show the law of latitudinal progression, the wave

like character of the advance is even better disclosed

by the curves. As the eye follows them down the

page, the advance of the wave to the right is plainly

apparent. The slope of the wave is much the same for

all, implying that a like force was at work successively

down the latitudes.
302 MARS AND ITS CANALS CHAP. XXIII

It will be noticed next that in all the mean car

touches the gradient is greater after the minimum

than before it. The curves fall gently to their lowest

points and rise more steeply from them. Such profile

indicates that the effects of a previous force were slowly

dying out down to the minimum and that then an im

pulse started in to act afresh. This explains the atti

tude of the canals that died out. In them the effect

of the old force shows as in the others, but no impulse

came in their case to resuscitation.

It seems possible to trace this force to an origin at

the south. For beginning with the north sub-tropic

zone the gradient on the left shows less and less steep

southward to the south sub-tropic zone. Such a

dying-down swell is what should be looked for in an

impulse which had travelled from the south northward,

since the wave would affect the more northern zones

last, and less of a calm period would intervene between

the two impulses from opposite poles.

The cartouches, then, state that the canals began to

develop after the greatest melting of the polar cap

had occurred; that this development proceeded down

the latitudes to the equator, and then not stopping

there advanced up the latitudes of the other hemi

sphere. In the next place they show that in the

arctic region the development was arrested and devo

lution or decay set in as it began to get cold there,
chap, xxin CANALS : KINEMATIC 303

the most northern canals being affected first. Finally,

that a similar wave of evolution had occurred from

the opposite pole some time before and had then

passed away. And this evidence of the cartouches

is direct, and independent of any theory.
CHAPTER XXIV

CANAL DEVELOPMENT

Individually Instanced

A S an interesting instance of the law of development we may take the career of the Brontes

during this same Martian year; the Brontes witness

ing individually to the same evolutionary process that

the canals collectively exhibit.

The Brontes is one of the most imposing canals upon

the planet. It is not so much its length which renders

it a striking object, though this length is enough to

entitle it to consideration, being no less than 2440 miles.

Its direction is what singles it out to notice, for it runs

almost north and south. For this reason it swings into

a position to hold the centre of the stage for a time with

the precision of a meridian, as the planet's rotation

turns its longitude into view. The points which it

connects help also to add to its distinction. For the

Sinus Titanum at its southern end and the Propontis

at its northern are both among the conspicuous points

of the disk. The latter is but twelve degrees farther

east than the former, while it is sixty-six degrees farther

north. This long distance, —from nearly the line of the

tropics in the southern hemisphere to mid-temperate

304
chap, xxiv CANAL DEVELOPMENT 305

regions of the northern, — the canal runs in an

absolutely straight course.

Its north and south character commends it for any

investigation of canal development, since it runs in the

general direction that development takes. Its great

latitudinal stretch further fits it for a recorder of

changes sweeping down the disk ; so that both in di

rection and length it stands well circumstanced for a

measure of latitudinal variations. The fact that it is

usually a fairly conspicuous canal does not detract from

its virtue in this respect. It was first recognized at

Flagstaff in 1894. But once realized, so to speak, it was

possible to identify it with a canal seen by Schiaparelli

and supposed by him to be the Titan; indeed, it played

hide and seek with that canal throughout his drawings.

In 1894 both it and the Titan were so well seen that its

separate existence was unmistakable, causing it to be

both recognized and named. It is, like the Titan, one

of the sheaf of canals descending the disk from the

Sinus Titanum, and lies just to the east of the Titan in

the bunch. In 1896 it was also prominent; and at

both these oppositions most so from its southern end,

its northern one being more or less indefinite, especially

in 1894.

In 1901 it was not the same. Instead of being the

conspicuous canal it had been in earlier years, it was

now so faint as with difficulty to be made out. It

X
306 MARS AND ITS CANALS CHAP. XXIV

remained so to the close of observations. It was now

under suspicion. Its behavior in 1896-1897 had led

to the supposition that not only were seasonal changes

taking place in it, but that those changes were such as

to point to a law in the case with which its conduct in

1901 fayed in. The suspicion did not, however, be

come a certainty till the opposition of 1903. The length

of time during which the disk was then kept under scru

tiny resulted in the method of its metamorphosis being

discovered.

At the very start of observations its longitude chanced

to be nearly central and it was made out ; but so far off

next presentation the planet was nearer, and details

previously hidden for the distance now came out.

Among them was the Brontes, which, showing better

than in January, could be traced all the way to the

Sinus Titanum. A drawing (I) made on February 25

 

I. February 26.

was the planet that only its

northern part could be de

tected, because, as after

ward appeared, this part

was the stronger, the canal

being decidedly inconspicu

ous, whereas other canals,

the northern and even the

Pallene and the Dis, were

strongly marked. At the
chap, xxiv CANAL DEVELOPMENT 307

 

II. March

and reproduced in the text shows its appearance at

the time. Its emergence under neared conditions

only served to accentuate

its relative inconspicuousness, for it showed now

notably inferior to the

northern canals, and this

not only in the matter of

general visibility, but in

the character it displayed.

It was a line of hazy defi

nition, contrasting thus

with the sharp dark forms of its northern neighbors.

As the planet steadily approached the earth, and the

canals to the north became

better and better seen, the

Brontes instead of sharing

in the general improve

ment did exactly the op

posite. It grew less visible

when it should have grown

more so, if distance had

been the cause of its ap

pearance. It was now

only to be seen at the north, even when it was seen

at all ; a state of things exemplified in Drawings II

and III.

 

III. April 3.
308 MARS AND ITS CANALS chap, xxiv

 

IV. May 4.

As the planet now went away and detail should have

dimmed, the Brontes proceeded to do the opposite. One

had almost said it was actuated by a spirit of con

trariety. For now when it

had reason to grow faint

it grew in conspicuousness; just as, before, when

it should have become evi

dent, it had declined. Dis

tinctly farther off and

smaller as the planet was

at the next presentation,

the Brontes had clearly

developed both in tone and in the amount of it visible.

This was in May (Drawings IV and V). In June bad

seeing prevented good ob

servations, but in July,

Drawing VI, when the re

gion again came round, the

Brontes, in spite of the then

greatly increased distance,

asserted itself so strongly

that even in not very good

seeing its presence could

not be passed by.

This contrariety of behavior had about it one very

telling feature. That the canal waxed or waned in exact

 

V. May 7.
CHAP. XXIV CANAL DEVELOPMENT 309

opposition to distance and even toward the last to see

ing too, showed conclusively that neither distance nor

definition could in any way be held responsible for its

metamorphoses. A very fortunate circumstance, this of

the observations, for it directly eliminated size of disk,

phase, and seeing, for which correction are none too easy

to make, and which in the minds of the sceptical could

always remain as unex

plained The possibilities mean-canalof error. car

touches show synthetically,

and all the more conclu

sively for being composite,

the laws of the flux of the

canals. Something more of

vividness, however, is im- VI. July 18. one partedof bythetheconstituents actual lookduring of the process. It is the

difference between seeing a composite picture made

from a given group of men and the gazing on the actual

features of any one of them. So much is gained by the

drawings across the page of the Brontes at different

stages of its evolution during the period here concerned.

But in another way, too, the one canal may be made to

yield a more lifelike representation of the process than

a number taken together are capable of affording. In

the mean-canal cartouches each canal is treated as an

 
310 MAES AND ITS CANALS chap, xxiv

entity ; but it is possible to consider a canal by parts,

and by so doing to see it in action, as it were. It

occurred to me to treat the Brontes in this way. For

this purpose I divided the canal into sections, five of

them in all, between the point where it left the Propontis, at a spot called the Propropontis, to where it

ended in the Sinus Titanum. The first, the most

northern, extended as far as Semnon Lucus, the south

ernmost outpost of the Propontis congeries of spots.

The second continued on from these to Eleon, the

junction where the Erebus crossed. The third thence

to Utopia, where the canal met the Orcus; the fourth

to an arbitrary point in latitude 8° south, and the fifth

and last to the Sinus Titanum. The lengths of these

sections were respectively: 12°, 16°, 15°, 12°, and 13°.

Each of the sections was then treated as if it were a

separate canal and its cartouche found. To the car

touches' determination there were available drawings:

January March February April June 3-16 26-May 28-21-25 23-March April8 5 2 .... . . . 2712546 drawings. drawings. drawings.

July 11-21 16 drawings.

90 drawings in all.

The cartouches are given in the plate opposite,

which is constructed precisely like the one for the mean
chap, xxiv CANAL DEVELOPMENT 311

canal cartouches presented on page 298. The mid-lati

tude of the section and its mid-longitude are given in

the margin with its description.

Examining them now we note a family resemblance

between the successive cartouches. All sink slowly

Daylbt/or, Daysafter 

. m i.nniW/xx^, MKONTES © nunfM - - showing Successive Development South January to JuZytrgcy

on the left to rise sharply from their lowest point to the

right. Such resemblance betokens the action of one

and the same cause.

Next, although the curves are resemblant, each has

been, as it were, sheered to the right as one reads down ;

that is, the action took place later and later as the

latitude was north.

Lastly, the dying out of a previous impulse can be
312 MARS AND ITS CANALS chap, xxiv

traced in the cartouches, which shows that the canals

were quickened six months previously from the south

polar cap, as they were now being quickened from the

north polar one.
CHAPTER XXV

HIBERNATION OF THE CANALS

QONNECTED with the conduct of the canals is a

phenomenon, examples of which were early noted

in a general way by Schiaparelli and later, but of

which the full import and exhibition only came to light

during the opposition of 1903 by a very striking meta

morphosis: what may be called the hibernation of a

canal for a longer or shorter term of years. What

observation discloses is certainly curious. For several

successive oppositions a canal will be seen in a definite

locality, as regular in seasonal recurrence as it is per

manent in place, a well-recognized feature of the disk.

Then to one's surprise, with the next return of the

planet, it will fail to appear, and will proceed to remain

obliterate without assignable cause for many Martian

years, until as unexpectedly it will be found what and

where it was before. Neither to deposition of hoar

frost, such as frequently whitens whole regions of Mars,

nor to other circumstances can be attributed its dis

appearance. Without apparent reason it simply ceases

to be and then as simply comes back again.

313
314 MARS AND ITS CANALS chap, xxv

Such bopeep behavior is quite beyond and apart

from the seasonal change in visibility, to which all the

canals are by their nature subject. For being creatures

of the semi-annual unlocking of the water congealed

about the polar caps, they quicken into growth and

visibility, each in its season, and as regularly die out

again. Different, however, is the phenomenon to

which I now refer. In it not a seasonal but a secular

change is concerned. The season proper to the canal's

increase will recur in due course, and the canals round

about it will start to life, yet the canal remains unquickened. Nothing responds where in years the response

was immediate and invariable. The canal lies dormant

spite of seasonal solicitation to stir.

Such curious hibernation was early hinted to the

keenness of Schiaparelli, and most incomprehensible as

well as difficult of verification at that stage the phe

nomenon was. That the absence was a fact, however,

he assured himself, although he was not able to prove

an alibi. But at the last opposition an event of the

sort occurred which, from the length of time the planet

was kept under observation, combined with continued

suitableness of the seeing, unmasked the process. In

the light of what then happened, taken in connection

with the side-lights thrown upon it by the canal's past

and by the knowledge we have meanwhile gained of the

planet's physical condition, the riddle of the phenome
chap, xxv HIBERNATION OF THE CANALS 315

non may in part at least be read, and most interesting

and instructive the reading proves to be.

Among the initial canals detected by Schiaparelli,

in 1877, was a tricrural set of lines recalling the heraldic

design of three flexed legs joined equiangularly above

the knees. It lay to the east of the Syrtis Major, and

he called its three members the Thoth, the Triton, and

the Nepenthes. Starting from the head of his gulf

of Alcyonius, at a point now known to be occupied by

the oasis called Aquae Calidae, the Thoth started

south inclining westward as it went, till in longitude

267° and latitude 15° north, it met the Triton, which

had come from the Syrtis Minor with similar westward

inclination. To the same point in the same manner

came the Nepenthes. Part way along the course of the

latter was to be seen a small dark spot, the Lucus

Moeris, which he estimated at four degrees in diameter.

Some of the markings were easier than others, the

easiest of all being the Lucus Tritonis, a largish dark

spot at the common intersection of all three canals;

but that none of the markings were remarkably diffi

cult is sufficiently shown by their detection at this early

stage of Schiaparelli's observations. It is worth noting

also that he discovered the southern ones first; the

Thoth not being seen till March, 1878. As his then

recognition of these canals witnesses, they must have

been among the most evident on the disk. And the
316 MARS AND ITS CANALS chap, xxv

point is emphasized by the fact that he failed at this

opposition to detect the Phison and the Euphrates

as separate markings.

Much the same the three canals appeared to him at

the next opposition of 1879, the Thoth being seen at its

several presentations from October 5, 1879, to January

11, 1880.

At the next opposition a noteworthy alteration

occurred, the full significance of which escaped recog

nition. Schiaparelli saw, at the place where the Thoth

had been, two lines which he took for a gemination of

that canal, one of which followed the course of the old

Thoth, while the other went straight from the Sinus

Alcyonius to the Little Syrtis, or, more precisely, to the

junction of the Triton and the Lethes. It was not the

Thoth, however, but something unsuspected, of more

importance.

In 1884 the Thoth showed really double, the western

line being much the stronger, "una delle piu grosse

linee que si vedessero sul disco." That neither branch

went farther than the meeting-place with the Nepen

thes argues that it was indeed the Thoth that was seen.

Schiaparelli himself had no doubt on the subject, al

though he drew the double canal he saw due north and

south from the tip of the Sinus Alcyonius to the junc

tion, but nevertheless along the 263° meridian.

In 1886 and 1888 the system was in all essentials,
chap, xxv HIBERNATION OF THE CANALS 317

what it had been in 1877 and 1879, except that the

Thoth and Nepenthes were double and were more

minutely seen.

Here, then, was a system of canals and spots which

for six Martian years had been a persistent and sub

stantially invariable feature of the Martian surface.

Any changes in it had been of a secondary order of im

portance, while its general visibility was of the first.

It is possible, then, to judge of my perplexity when in

beginning my observations in 1894 no sign of the system

could I detect. Of neither the Thoth, the Triton, the

Nepenthes, nor the Lucus Moeris was there trace. And

yet, from the other canals visible, it was evident that

the disk was quite as well seen as it had been by Schiaparelli. Not only were practically all his canals there,

but many much smaller ones were to be made out.

And the same was true of the spots, a host of such not

figured by him appearing here and there over the

planet's surface.

Nor was this all. Instead of the Thoth, another canal

showed straight down the disk from the Syrtis Minor

to the Aquae Calidae. This canal was as unmistakable

as the Thoth had been before to Schiaparelli. It was

among the first to be detected, and continued no less

conspicuous to the end, the dates at which it was seen

being July 10, August 14, and October 21. I called it

the Amenthes, identifying it with the canal so named
318 MARS AND ITS CANALS chap, xxv

in Schiaparelli's chart published in Himmel und

Erde, of the ensemble of his observations from 1877 to

1888. But in his Memoirs he never called it so, seeing

it, indeed, only in 1881-1882, and deeming it then the

Thoth. Nevertheless, in 1894, it was the conspicuous

canal of the region, and, what is more, had come, as

it proved, to stay.

The invisibility of the Thoth continued for me the

same during the succeeding oppositions of 1896-1897

and 1901. At the former opposition I drew it in 1896

on July 28, August 26, September 2, October 5-9,

seeing it single; and in 1897 on January 12-19, Febru

ary 21, and March 1. It was single but with suspicions

of doubling in January, and was indubitably double in

February. As for the Thoth, I had come to consider

it and the Amenthes one, attributing their diversity

of depiction to errors in drawing. For while the Thoth

remained obstinately invisible, the Amenthes presented

itself as substitute so insistently as to make one of the

most obvious canals upon the disk.

One exception only was there to this state of things.

On June 16, 1901, my notes contain this adumbration

of a something else: "Amenthes sometimes appeared

with a turn to it two-thirds way up; two canals con

cave to the Syrtis Major."

So matters opened at the opposition of 1903. With

the advent of the planet and the presentation in due
chap, xxv HIBERNATION OF THE CANALS 319

 

Amenthes alone in February.

course of Libya in February, the Amenthes duly ap

peared, much as it had showed at the opposition before,

only less salient. It was a

confused and seemingly nar

rower double. Suspected

on the 16th of that month,

it was definitely seen from

the 18th to the 23d. Of

the Thoth no mention is

made either in the notes or

in the drawings. When the

region came round again, in

March, the Amenthes was still there, showing more

feebly, however, than it had in February, in spite of

better seeing and the fact

that the planet had consid

erably neared. Clearly the

canal was fading out ; a fact

further witnessed to by the

following note made on

March 25: "Throughout

this opposition thus far the

dark triangle tipped by

Aquae Calidae has been

sharply divided in intensity from the Amenthes, which

is very narrow and exceedingly faint." Still was

there no trace of the Thoth.

 

Amenthes feebler and still alone in March.
320 MARS AND ITS CANALS CHAP. XXV

With the April presentation entered a new order of

things. When the region first became visible, on the

16th, the Amenthes could still be seen and alone;

but on the 19th, as the relative falling back of the MarAppearance of Thoth with Tri- the Triton and the curved

ton and curved Nepenthes. Nepenthes. The thing was

had seen only in the spirit of another's drawings stood

there patent to me in the body of my own ; while the

Amenthes, to which I had so long been accustomed,

had vanished into thin air. Only a trace of it was

now and then to be made out. So startlingly strange

was the metamorphosis that I could not at first trust

my eyes, and questioned the broken line, which had

replaced the straight, for some ocular deception. But

nothing I could do would rectify it. The Amenthes

was gone and the Thoth stood in its stead.

At the next presentation, May 26 to June 8, the

phenomena were repeated, and with increasing clarity.

 tian longitudes swung the

region nearer the centre of

the disk, the Thoth appeared

alongside of it. On the

20th the Thoth showed

alone. Unmistakable it was

and just as Schiaparelli had

drawn it, accompanied by

 

a revelation. What before I
chap, xxv HIBERNATION OF THE CANALS 321

And then of a sudden, on May 29, I saw the longgiven-up Lucus Moeris. There it was indubitably.

And its definiteness was the most astonishing part of

the affair. It was no question of difficult detection.

Indeed, I had not been on the lookout for it, having

searched the region too often

fruitlessly before to have

left incentive to search again.

And so, when I was not

searching, the thing of its

own accord stepped forth

to sight. It was a small

round dot, like to any other

Oasis, and Showed, as it Were, Advent of the Lueus Moeris. May 29. atheblack Nepenthes pearl from pendent the Syrtis's by ear. For the Libyan

bay made a dark projection of the sort high up on the

Syrtis's eastern side, from which the Nepenthes, pre

cisely as Schiaparelli had drawn it, curved down to the

point where the Thoth and Triton met. All three

canals were geminated, the gemination being about

three degrees wide.

And now occurred the last act in the drama. In

July the Amenthes reappeared, showing alongside of

the Thoth-Nepenthes, and thus removing any possible

doubt as to their separate identity. It had, indeed,

become the stronger of the two, having gained in

 
322 MARS AND ITS CANALS CHAP. XXV

strength in the interval between June and July and

the Thoth-Nepenthes having lost. The lines were in

process of relapsing into the status quo ante. Had

these three presentations not been watched, the brief

apparition of the Thoth-Nepenthes had been missed

and with it the revealing of

its curious character, and

of certain deductions there

upon.

First among these is a

truth of which I have long

been convinced ; to wit, that

when a seeming discordance

Amenthes with Thoth,Nepenthes. arises of a canal, betweenit the is commonly portrayals

not a case of mistake nor of change, but one of separate

identity. The canal has not shifted its place, nor has

an error been committed; the fact is that one canal

has been observed at one time, another at another.

So it was here, and thus were the old and the new

observations reconciled. There had been no mistake

in either. Two separate canals accounted for the dis

crepancy, and only an unfounded distrust of the accu

racy possible in such observations was to blame for

any failure to recognize the fact.

Now, scrutiny of the notes upon the appearance of the

two canals, together with their labeling by the seasonal

 
chap, xxv HIBERNATION OF THE CANALS 323

longitudes of the planet at the dates they were made,

discloses a curious relation between the two. The

seasonal longitudes are important, as they date the

phenomena according to the Martian calendar. Or

dered thus, the successive aspects reveal first a seasonal

change in each canal and then over and above this a

 

Cahtouches

Cviycs cf Visibility OF

AntHTHCS , ThoTH jnj Th£.IR ComBIHATIOH

secular one. And this secular change was such as to

cause the two canals to alternate in visibility. When

the one was present the other was not, and vice

versa.

We shall see this more clearly and at the same time

bring out a curious relation between the two systems,

the broken bow of the Thoth-Nepenthes-Triton and the

straight arrow of the Amenthes, while looking at the
324 MARS AND ITS CANALS chap, xxv

cartouches of the Thoth, the Amenthes, and a combi

nation of both given in the plate on previous page.

The antithetical character of the two canals is appar

ent. But what is further interesting, the combination

cartouche of both bears a singular resemblance to that

of the mean canal of the north tropic zone, the zone

to which both canals belong. Here, then, is a combi

nation which is perfectly regular while each of its con

stituents is anomalous.

And now we come to something as important: at

the opposition of 1905 the curious alternation meta

morphosis was enacted anew. The Amenthes appeared,

disappeared to be replaced by the Thoth, and then re

appeared again beside the other. This corroboration

of behavior showed the previous observations to have

been due to no mistake, and only served to deepen the

interest in this last and more singular phase of canal

conduct.
CHAPTER XXVI

ARCTIC CANALS AND POLAR RIFTS

J^AST in time but not least in importance of the

details of canal development to be detected is one

that connects these strange features directly with the

melting of the polar caps. The cartouches showed

that such connection was to be inferred ; the facts now

to be recorded depict it by an identity of place between

certain phenomena of the two subjects following one

another in order of time.

On January 8, 1897, while scanning the planet, I

was suddenly ware of a rift in the north polar cap. It

ran a little to the west of south from where it started

in at the cap's edge and went clean through to the limb,

the pole being then slightly tilted away from us. At the

time it seemed to be the first rift ever seen in that

cap ; but on opening a little later Schiaparelli's Memoria

Quarto, which had just arrived, the first thing my eye

fell on was a drawing of a rift in the north polar cap

observed by him when the planet had held the like

attitude toward the Earth thirteen years before. Ref

erence to its longitude showed it to be the identical

825
326 MARS AND ITS CANALS chap, xxvi

rift, seen again after all these years and the only one

so far seen in the northern cap.

At the next opposition more rifts were detected, one

in especial on December 27, running from Arethusa

Lucus, then upon the edge of the cap, athwart the

snow in a northwesterly direction.

In the forepart of the opposition of 1901, which in its

Martian season corresponded to that in 1897, when the

rift had been observed, many rifts were detected in the

cap, and among them one traversing the cap northnortheasterly in longitude 136°.

So far the season when the cap had been observed

was that when the rifts were in process of forming.

The ground they and the snow-cap covered had not yet

at any opposition been uncovered.

It was only when my observations began in the

latter half of the opposition of 1901 that, the season on

Mars having so far advanced, all snow in those latitudes

had melted. Then appeared, however, the canal

Hippalus, an arctic canal of some importance, lying

on that part of the planet previously occupied by the

polar cap. When later studying the observations

on the rifts I remembered this canal, and turning

to the drawing made some months before to compare

the two critically, discovered that the canal occupied

the precise position held earlier by the rift. One had

said the rift had never vanished, but that the white
ciiap, xxvi CANALS AND RIFTS 327

surrounding it had simply turned to ochre. Here,

then, was a striking coincidence of place, too exact to

be the result of chance.

Impressed by the identity, I examined all the other

rifts seen early in 1901, comparing them with the arctic

canals seen later, to the finding of no less than five cases

of the same coinciding positions.

The importance of the identification here made of an

arctic canal with a previous rift in the polar cap has

led me to make a list of the canals thus identified at

this opposition.

Visible as a Rift Visirle as a Canal

Hypanis January 1 and February 4 April 27, June 18 (?), 4, 5,May6, 7,20,22, 8,5

Hippalus January 19 and February 4 April 18, May 27

Rhombites February 4 May 27

Python February 20 March 31

Zygatis January 18, 19 May 7, June 3 to 8

If it be asked why these canals do not appear recorded

at the March presentation as either the one phenomenon

or the other, the answer is twofold. First, because they

showed as shadings lost amidst a shaded mass; and,

secondly, the observations at several oppositions indi

cate a great amount of haze over the region at that

season of the Martian year.

We may now go back to the very first rift, that of

1897. The Martian season grew later with each sue
328 MARS AND ITS CANALS chap, xxvi

ceeding opposition, and it so chanced, abetted by this

fact, that the delaying snow was never seen covering

that part of the planet again and so, of course, not

the rift. The Martian summer in those high lati

tudes came on, and with it brought the great arctic

canal, the Jaxartes, into conspicuousness. The canal

in consequence had been observed for some time

before it proclaimed itself the apotheosis of a rift

and that of the first and most important rift of all.

Comparison of position, however, entirely confirmed

the conjecture and added another and the most

striking of all to the list.

These six canals, on the whole the largest which run

into the northern cap, have thus a dual character.

Starting originally as rifts, they later come out un

mistakably as canals. So that we may say in general

that the two phenomena are different seasonal states

of the same thing. This instantly explains the rifts,

the origin of which we found of so difficult, not to say

impossible, interpretation before in these pages, and

incidentally it confirms what we deduced on other

grounds as the character of the canals; to wit, strips

of vegetation. For if the cap covered desert and

fertility alike, it is precisely over the latter that it

would first melt.

Vegetation has the property of melting snow. The

metabolism of the plant , like that of the animal, though
chap, xxvi CANALS AND EIFTS 329

in a less degree, generates caloric. A living animal is

warm, even the so-called cold-blooded ones, in some

sort, and a growing plant is too. The chemic processes

concerned give off heat, though in such small quantities

that we are often not aware of it. While the plant lies

dormant it stays cold, but the moment its sap begins

to run under the rays of the spring sun it rises in

temperature above its winter surroundings. All it

needs to this awakening is sun and water, and both it

gets in its place in the polar cap after the passing of the

vernal equinox. The time, therefore, is suitable, for

it is not till after that equinox is passed that any of the

above phenomena occur. In consequence the snow

about it melts and the plants themselves show as

dark rifts splitting the cap.

This quite unexpected identity of two seemingly

diverse phenomena, and the unsolicited support its

only explanation lends to the general theory, is an

instance of what is constantly occurring as observa

tion of the planet is pushed farther and farther. Facts

every little while arise which prove to fit into place in

the scheme when neither the facts nor their fitness

could have been foreseen.
CHAPTER XXVII

oases; kinematic

QUBJECT to change also are the oases ; and in the

same manner apparently as the canals. They

grow less evident at a like season of the Martian year.

They do this seemingly by decreasing in size. Whereas

in the full expanse of their maturity they show as

round spots of appreciable diameter, as the season

wanes they contract to the smallest discernible of dots.

All but the kernel, as it were, fades out, and even this

may disappear from sight. The Phoenix Lake in

its summer time is a very dark circular spot, small

indeed yet of definite extension ; in its winter it shrinks

to a pin point, and is often not visible at all. Some

times the husk apparently persists, a ghostlike remi

niscence of what it was, with the kernel showing darkpointed in its centre. Thus the Lucus Lunae appeared

at the opposition of 1905. A faint wash betokened the

presence of the Lucus, through which now and again

a black pin-point pierced.

In this visible decrease of size we get a revelation as

to what takes place impossible in the case of the canals,

330
CHAP. XXVII OASES; KINEMATIC 331

the tenuous character of which precludes more than

inference as to the process.

Like the canals, latitude, together with the suitable

season of the planet's year, are the determining factors

in their development. In what corresponded to our

July of the northern hemisphere the oases in the

sub-arctic and north temperate zones were conspicu

ous; black spots that showed in profusion along the

parallels of 40°, 50°, and 60° north. At the same

time the equatorial ones, those along the EumenidesOrcus, which had been most evident in 1894, hardly

came out. It had been their time then as it was that

of the others now. The law of development is not so

simple as on the earth, depending, like that of the

canals, not only upon the return of the sun, but upon

the advent of the water let loose from about the

polar caps. Thus the equatorial oases are subject to

two seasonal quickenings, one from the north, the

other from the south.

In regard to their method of evolution or devolution

a most curious observation happened to me in 1903.

Usually the oases are of solid tone throughout ; equally

sombre from centre to circumference. But in this

case such uniform complexion found exception. On

March 1, 1903, the Ascraeus Lucus came out strangely

differentiated, a dark rim inclosing a less dark kernel.

The sight was odd enough to command comment in the
332 MARS AND ITS CANALS chap, hvm

shape of a sketch which accompanied the note, and the

further remark that other spots had similarly that year

affected the like look. That the effect was optical did

not seem to me the case. Other spots at other times

showed nothing of the sort. If it was due to objective

cause it gathers circumstance from what was then the

Martian time of year. For the season was such that

the spot should then have been in process of waning;

and the effect would indicate that in so doing the tone

of the centre went first, that of the circumference fading

last. This would be in accordance with a growth

proceeding outward and a decay that followed in its

steps.

When to this we add the look of the oases at the

antithetic season, — often a faint shading only, with or

without a darker pin-point at its core, — we are led

to the belief that the area of the oasis is unchangeable

and that its growth means a deepening of tint.

So far, then, as it is possible to particularize them,

the oases develop from a small nucleus, perhaps twenty

miles in diameter, perhaps less, and from this spread

radially till they attain a width of seventy-five or one

hundred miles. If the oasis be associated with a double

canal, this maximum width exactly fits the space be

tween the twin lines. Even when no double enters

the oasis, the size is about the same. This size attained,

they hold it for some months. Then they proceed to
CHAP. XXVII OASES; KINEMATIC 333

fade out to their initial nucleus, and after a sufficient

rest the process starts over again.

With the carets something of the same sort seems to

take place — if we may consider as betokening a gen

eral law the fact that in 1894 the carets at the mouths

of the Phison and Euphrates developed before their

affiliated canals. But about them much less is yet

known, and we must be content to say that the obser

vations of 1905 made at the opposite season of the

canal's year seem to bear this out.
I

i
PART IV

EXPLANATION
i
CHAPTER XXVIII

CONSTITUTION OF THE CANALS AND OASES

S results, rational itscience now does becomes not rest obligatory, content with by marraw

shaling the facts to suitable discussion, to seek to find

out what they mean. Now, so soon as we scan these

phenomena for some self-interpretation, we perceive

one characteristic of the lines which at once appears

to direct us to their nature and justifies itself as a sign

post with increasing certainty as we read on. This

trait is the very simple yet most significant one of

showing intrinsic change : the lines alter in visibility

with time. This primary proclivity we do not even need

the cartouches to establish. That the lines change is

palpable to any one who will watch them long enough.

Schiaparelli was struck by the fact early in his study of

the planet, and it forces itself on the notice of any care

ful observer who compares his own observations with

one another at intervals. But though the cartouches are

not needed to a first revelation of mutability, they serve

to certify and precise it to much further information on

the subject. For, that these changes are not extrinsic,

that is, are not caused by varying definition, distance,

 

z :r,~
338 MARS AND ITS CANALS chap, xxvm

or illumination, they make patent even to those who

have never seen the things themselves by disclosing

respective differences of behavior in lines similarly

circumstanced optically. The change is therefore

intrinsic, and the question arises to what can such in

trinsic change be due.

In searching for cause, attention is at once attracted

by another series of transmutations that manifests

itself upon the disk, in the orderly melting of the polar

caps. For the existence of the two sets of metamor

phoses suggests the possibility of a connection between

them. The inference is strengthened when we note

that not only are both periodic, but that furthermore

the period of the two is the same. Each polar cap

runs through its gamut of change in a Martian year;

the canals also complete their cycle of growth and decay

in a Martian twelvemonth. The only difference be

tween the two is that each polar cap has but one maxi

mum and one minimum in the course of this time,

while most of the canals have two of each, though the

maxima are not alike nor the minima either.

Not only is the period of the two series of changes the

same, but the one follows the other. For the develop

ment of the canals does not begin till the melting of the

polar cap is well under way. Now, as the polar cap

disintegrates it gives rise, as we have seen, to a dark belt

of blue-green which fringes its outer edge and retreats
chap, xxviii CONSTITUTION OF CANALS 339

with it as it shrinks. This tells, directly or indirectly,

of a product let loose. After this belt has been formed

the canals nearest to it proceed to darken, then those a

little farther off follow suit, and so the wave of visibility

rolls in regular routine down the disk. Here, then, at

the outset we have a chronic connection between the

two phenomena, the disintegration of the cap and the

integration of the canals.

Of water we saw that the caps were undoubtedly

composed, and to water, then, let loose by the melting

of the cap, we may inferably ascribe the thaumaturgy

in the development of the canals. But it is not neces

sary to suppose that this is done directly. That the

increased visibility of the canals can be due to a bodily

transference of water seems doubtful, if for no other

reason than the delay in the action. Considerable

time intervenes between the disappearance of the

cap and the appearance of the canals, except in the

case of such as have been covered by it. Transforma

tion consequent upon transference, however, would

account for hesitancy. A quickening to vegetal

growth would produce the counterpart of what we

see. If, set free from the winter locking up, the water

accumulated in the cap then percolated equatorward,

starting vegetation in its course, this would cause

the increased visibility of the canals and at the same

time explain the seeming delay, by allowing for the
340 MARS AND ITS CANALS chap, xxvni

time necessary for this vegetation to sprout. This

is certainly the most satisfactory explanation of the

phenomena.

Thus started, the vegetal quickening would pass

down the planet's surface and give rise to what we mark

as seasonal change. But, though in one sense of sea

sonal character, a little consideration will show that

it would be quite unlike the seasonal change which we

know on earth.

Could we see our earth from some standpoint in

space, we should mark, with the advent of spring, a

wave of verdure sweep over its face. If freedom from

cloud permitted of an unimpeded view, this flush of

waking from winter's sleep would be quite evident and

could be seen to spread. Starting from the equator so

soon as the sun turned north, it, too, would travel north

ward, and, distancing the sun, arrive by midsummer

well into the arctic zone. Here, then, we should note,

much as we note it on Mars, a tint of blue-green super

pose itself successively upon the ochre ground; but

the mundane and the Martian vegetal awakening

would differ in one fundamental respect; the earthly

wave would be seen to travel from equator to pole,

while the Arian travels from pole to equator. Though

clearly seasonal in character, both of them, the trans

formations would be opposite in action. Some other

cause, then, must be at work from what we are familiar
chap, xxviii CONSTITUTION OF CANALS 341

with on earth. This other cause is the presence or

absence of moisture.

Two factors are necessary to the begetting of vegetal

life, the raw material and the reacting agent. Oxygen,

nitrogen, water, and a few salts make up the first de

sideratum, the sun supplies the second. Unless both

be present, the quickening to life never comes. Now,

the one may be there and the other not, or the other

there and the one not. On earth the material includ

ing water is, except in certain destitute localities,

always present ; the sun it is that periodically with

draws. Observant upon the return of the sun is there

fore the annual recurrence of vegetal growth.

On Mars, on the contrary, water is lacking. This

we now know conclusively from other phenomena the

disk presents which have no connection with the present

investigation and are, therefore, unprejudiced witnesses

to the fact. No permanent bodies of water stud its sur

face. That the so-called seas are traversed by dark

lines permanent in place is one of several proofs of this.

The only surface water the planet knows comes from

the melting of its polar caps. Vegetation cannot start

until this water reaches it. Consequently, though the

sun be ready, vegetation must wait upon the coming

of the water, and starting from near the pole follow

the frugal flood equatorward.

Now, such contrariety of progression to what we
342 MARS AND ITS CANALS chap, xxviii

should observe in the case of the earth could we view

it from afar is exactly what the curves of visibility of

 JJayt tx/ter

PHENOLOWCl'RVES-EARTH. A - Dud Point of Vffttjtion.

(From paper in Proc. Amer. Phil. Soc, by Pereival Lowell.)

the canals exhibit. Timed primarily, not to the re

turn of the sun but to the advent of the water, vegetal

quickening there follows, not the former up the lati

tudes but the latter down the disk. For better under
chap, xxvin CONSTITUTION OF CANALS 343

standing, the two curves of phenological quickening,

the mundane and the Martian, are shown in the dia-

 

«* Jtf 40' Off Aj' xv* JJV' tfo* lOtf lt<f JOtf J4C J4V JOtt S04' JOO* ffO' JIO' ftO* PHr.KOlOGYCl ,RVES-MAI,iS ik *, OmiJ Point ot Vfflttjt.on

(From paper in Proc. Amer. Phil. Soc, by Percival Lowell.)

grams. The plates represent the surfaces of the two

planets, that of the earth being shown upside down with

south at the top so as to agree with the telescopic de

piction of the topography of Mars. The stars mark the
344 MARS AND ITS CANALS . hap. ktiii

epoch of the dead-point of vegetation at successive

latitudes ; the time increasing toward the right. The

curves, it will be noticed, are bowed in opposite ways.

The bowed effect is due in part to Mercator's projec

tion ; in part it may represent a real decrease in speed

with time. But what is strikingly noticeable is the

opposite character of the advance to the right, the one

curve running up the disk, the other down it. This

shows that the development of vegetation proceeded in

opposite directions over the surface.

Thus is the opposed action upon the two planets

accounted for, and we are led to the conclusion that

the canals are strips of vegetation fed by water from

the polar caps, and that the floral seasons there as

affecting the canals are conditioned, not as they would

be with us, directly upon the return of the sun, but in

directly so through its direct effect upon the polar snows.

Once adventured on the idea of vegetation, we find

that it explains much more than the time taken

by the wave of canal-development down the disk. It

accounts at once for the behavior of the canals in the

three northern zones : the polar, arctic, and sub-arctic.

The mean cartouches of these three zones dip down

at their latter end instead of rising there, as is the case

with the cartouches of the mean canals farther south.

This dip denotes that the most northern canals were

waning already by the middle of their August, though

i

i
chap, xxviii CONSTITUTION OF CANALS 345

the others showed no such tendency ; while the date of

the deposition of the frost in these northern latitudes

shows that they were started upon their course toward

extinction before the snow itself had covered them. In

other words, they were not obliterated but snuffed out.

That their decline was thus preparatory to the coming

of the first snowfall or frost-fall, sufficiently severe to

'whiten the ground so that it did not melt the next

day, is suggestive of their ' constitution. It is clear

that they were not abruptly cut off by the frost, but

were timed by nature to such extinction. Vegetation

would behave in just this way, since evolution would

, accommodate the career of a plant to its environment.

The first question to present itself chronologically in

the canals' annual history is connected with the size

of the cap. Unfortunately for the simplicity of the

phenomena, the cap is not an extensionless source of

flow, but an extended surface melting from the outer

edge in. It would seem, therefore, that water liberated

from the outer parts should have an effect before the

main body of it were ready to begin its general march

down the disk. There should be, one would think,

at least a partial action, locally, before the main action

got under way. Now, there are certain canals that

show cartouches increasing apparently from the time

observations began, and the most pronounced is the

Jaxartes, which lies of all the canals observed the farthest
346 MARS AND ITS CANALS chap, xxvm

north. Now, the cartouches were founded on canals

quickened from the north polar cap. The farther north

the canal, therefore, the greater the likelihood of its

showing the phenomena.

That we note such canals is therefore not only not

subversive, but actually corroboratory, of the law it

seems at first to shake. That all the canals of these

zones do not show a like cartouche-profile is not neces

sary, a part of them being dependent, not upon the

earlier, but upon the later liberated flow, and thus par

taking in the general law, which grows uniform lower

down the latitudes.

As the action from one polar cap proceeds, not only

down to the equator, but across it into the planet's

other hemisphere, it appears that much, at least, of the

surface of Mars has two seasons of vegetal growth, the

one quickened of the north polar cap, the other of

the southern. How far the polar spheres of action

overlap it is not possible at present to affirm, as the

canals at this opposition were only visible to 35° south

latitude. That the north polar quickening goes down

so far is vouched for, and it is probable from other

observed phenomena that it goes farther.

The alternate semi-annual quickening also discloses

itself directly in the cartouches ; the previous semestral

growth from the south polar cap actually showing in

them before the impulse from the north began. The
chak xxviii CONSTITUTION OF CANALS 347

slow falling of their curves to the minimum preceding

their later rise is nothing less than the dying out of the

effect started six months before from the south. The

gentler gradient of their fall proclaims a gradual lapse,

just as the subsequent sharper rise points to the advent

of a fresh impulse. And this deduction seems to be

borne out by another circumstance. There is some

evidence of decrease in the pre-minimal gradient south

ward. This is telling testimony to the source whence

the impulse came. For if it originated at the south and

traveled northward, the southern canals would be the

first to be affected and the first to die out, and thus

show a longer dead season, exhibited in the cartouches

as a more level stretch.

Lastly, the explanation of the canals as threads of

vegetation fays in with the one which has been found to

meet the requirements of the blue-green areas; while

the fact that they prove to develop as they do, re

versely to what would take place on earth, is exactly

what all we have latterly learnt about the surface con

ditions of the planet would lead us to expect.

From what has just been said we see that the latest

observations at Flagstaff confirm the earlier ones, and,

what is especially corroborative, they do so along another

line. The former were chiefly static, the latter kine

matic. In other words, the behavior of the canals in ac

tion bears out the testimony of their appearance at rest.
CHAPTER XXIX

LIFE

(^TUDY of the fundamental features of Martian

topography has disclosed, as we have seen, the

existence of vegetation on the planet as the only ra

tional explanation of the dark markings there, con

sidered not simply on the score of their appearance

momentarily, but judged by the changes that appear

ance undergoes at successive seasons of the Martian

year. Thus we arc assured that plant life exists on the

planet. We are made aware of the fact in more ways

than one, but most unanswerably for that trait to which

vegetation owes its very name, — its periodic quicken

ing to life. Thus the characteristic which has seemed

here most distinctive of this phase of the organic, so

that man even christened it in accordance, has proved

equally telltale there.

Important as a conclusion this is no less pregnant as

a premise. For the assurance that plant life exists on

Mars leads to a further step in extramundane acquaint

ance of far-reaching import. It introduces us at once

to the probability of life there of a higher and more

immediately appealing kind, not with the vagueness of

348
CHAP. XXIX LIFE 349

general analogy, but with the definiteness of specific

deduction. For the presence of a flora is itself ground

for suspecting a fauna.

Of a bond connecting the two we get our first hint

the moment we look inquiringly into the world about

us, that of our own earth. Common experience wit

nesses to a coexistence which grows curious and com

pelling as we consider it. For it is not confined to life

of any special order, but extends through the whole

range of organisms of both kinds from the lowest to the

highest. Alga? and monera, orchid and mammal, occur

side by side and with a certain considerate poverty

or richness, as the case may be. Luxuriance in the one

is matched by abundance in the other ; while a scanty

flora means a poor fauna. This of which we have been

aware in regions round about us from childhood grows

in universality as we explore. Wherever man pene

trates out of his proper sphere he finds the same dual

possession of the land or the sea, and a similar curtail

ing or expanding of both tenantries together. No

mountain top so cold but that if it grow plants, it sup

ports insects and animals, too, after its kind ; no desert

so arid but that creeping things find it as possible a

habitat as life that does not stir. Even in almost

boiling geysers animalcula and conferva? share and

share alike. Only where extreme conditions preclude

the one do they equally debar the other.
350 MAES AND ITS CANALS chap, xm

Proceeding now from the fact to its factors we per

ceive reasons for this tenure in common of the land by

the vegetal and animal kingdoms. Examination proves

the two great divisions of the organic to be inextricably

connected. It strikes our notice first in the relation

of plants to animals. It is of everyday notoriety that

animals eat plants, though it is less universally under

stood that in the ultimate they exist on nothing else.

Plants furnish the food of animals ; not as a matter of

partial preference but of fundamental necessity. For

the plant is the indispensable intermediary in the pro

cess of metabolism. Without plants animals would

soon cease to exist, since they are unable to manufacture

their own plasm out of the raw material offered by in

organic nature. They must make it out of the already

prepared plasm of plants or out of other animals who

have made it from plants. So that in the end it all

comes back to plant production. The plant is able to

build its plasm out of chemical substances ; the animal

cannot, except in the case of the nitro-bacteria, begin

thusButat the the converse lowest rungof ofthisthedependence alimentary isladder. also largely

true. Plants are beholden to animals for processes

that in return make their own life possible. The latter

minister to the former with unconscious service all the

tune, and with no more arrogant independence than do

our domestics generally nowadays. The inconspicuous
CHAP. XXIX LIFE 351

earthworm is the fieldhand of nature's crops, who gets

his own living by making theirs. Without this day

and night laborer the soil for want of stirring had

remained less capable of grass. Above ground it is the

same story. Deprived of the ministrations of insects

many kinds of plants would incontinently perish. By

the solicited visits of bees and other hymenoptera —

what generically may be classed by the layman as

flutter-bys — is the plant's propagation made possible.

Peculiarly well named, indeed, are the hymenoptera,

seeing that they are the great matrimonial go-betweens,

carrying pollen from one individual to another and thus

uniting what otherwise could not meet. Spectacular

as this widespread commerce is, it forms but portion of

the daily drama in which animals and plants alike take

part. From forthright bargainings of honey for help,

we pass to less direct but no less effective alliance where

plants are beholden to animals for life by the killing

of their enemies or the weeding-out of their competitors,

and from this to generic furtherance where the inter

dependence becomes broadcast. In the matter of

metabolism the advantage is not all upon one side.

In the katabolic process of that which each discards

are the two classes of life mutually complimentary, —

the waste of the one being the want of the other, —

carbonic acid gas being given off by the animal, oxygen

by the plant. In biologic economy it is daily more
352 MARS AND ITS CANALS CHAP. XXIX

demonstrable that both are necessary constituents to

an advancing whole, and that each pays for what it gets

by what it gives in return.

That they are thus ancillary as well as coexistent to

day leads us to confront for them a community of origin

in the past ; and further study confirms the inference.

Both paleontology and entomology, or the science of

the aged and the science of the young, prove such an

cestry to be a fact. By going back from the present

into the past, or, what amounts to substantially the

same thing, by descending in the scale of life to the

lowest known forms of organism, we find proof of con

comitance, cogent because congenital. At the time

when inorganic chemical compounds first passed by

evolution into organic ones, the change was of so general

a character that even such tardy representatives of it

as survive today tax erudition to tell to which of the

two great kingdoms they belong, the vegetal or the

animal. Simplest and most primitive of known organ

isms are the chromacea, unnucleated single cells as

Haeckel has shown, and next to them in order come

many of the bacteria, also of simple unnucleated plasm.

So little do the majority of the bacteria differ mor

phologically from the chromacea, that on the score of

structure the two are not to be catalogued apart. Both

are as elemental as anything well can be, which only

their diet serves to divide. Each is an organism with
CHAP. XXIX LIFE 353

out organs, thus belying the dictionary definition of

both animals and plants. Etyinologically they are not

organic yet manifestly are alive, and only in their action

are unlike. The chromacea are plasm-forming beings,

and therefore they are plants ; the bacteria are plasmeating beings, and so are animals. Even this distinc

tion is not always preserved. As Haeckel tells us:

"the nitro-bacteria which dwell in the earth having the

vegetal property of converting ammonia by oxidation

into nitrous acid and this into nitric acid, using as their

source of carbon the carbonic acid gas of the atmos

phere. They feed, like the chromacea, on simple in

organic compounds." Here, then, we have, close to

the threshold of organic life, unorganized organisms,

roughly speaking coeval and differing in a sense but

little, either of them, from inorganic crystals; and yet

the one is an animal, the other a plant. Progenitors

of the two great divisions of life, they were themselves

concomitantly evolved, either side by side or as offshoots

both of a common stock. Now, if the ancestors of the

two great organic kingdoms were thus simultaneously

produced here, we are warranted in believing that they

would similarly be produced elsewhere, given conditions

suitably alike. In consequence, if we detect the pres

ence of the one, we already have an argument for infer

ring the other. Not to complete our syllogism Would

be to flaunt a lack of logic in nature's face.

2 A
354 MARS AND ITS CANALS chap, xxix

Rationally viewed, then, the general problem of life

in other worlds reduces itself to a question of condi

tions. Since certain physical results follow inevitably

upon certain physical premises, if we can assure our

selves of the proper premises we may look to nature for

their conclusion. A priori, then, the possibility of life

becomes one of habitat. If the environment be

suitable life will ensue. What makes for such a

mediary milieu is, like most cosmic processes, in its

fundamentals of interesting simplicity ; for the produc

tion of a proper nidus depends primarily upon the mere

size of the body parentally concerned. If a planet be

big enough it will inevitably bring forth life, because of

conditions suitable to its generating; if too small it

will remain sterile to the end of time.

That size should be the determining factor whether

a planet shall be fecund or barren may seem at first

thought strange. Yet that it is so admits of no rational

doubt. All that we see of bodies about us shows its

truth, and what we have learnt of cosmic process enables

us in some sort to discern why. In order for evolution,

such as we mark it upon the earth, to be possible, the

parent body must have been at one time at a high tem

perature, since only under great heat can the primal

processes occur. But for this generation of caloric

the aggregate mass of the particles, the falling together

of which makes the planet, and their stoppage its inter
CHAP. XXIX LIFE 355

nal heat, must be large. The sun's rays alone are insuf

ficient to cause the necessary temperature; the heat

must come from within, though it be helped from with

out. Even here the action is abetted by a large body.

For a planet to entrap the sun's rays or even to preserve

its own internal warmth, an atmosphere is needed, and

it takes a large body to retain an atmospheric covering

sufficiently long. Yet without it not only would there

be no suitable state, but no medium in which organic

or even inorganic reactions could go on. Lastly,

water, the essential nidus for the organism's early

stages, has its presence similarly conditioned. For this,

like the atmosphere, would from a small body speedily

vanish away. Thus the planet itself is the life-pro

ducing body, although the sun furthers the process

when once begun.

That the needed substances are planetarily present,

what we know of the distribution of matter astronomi

cally sufficiently attests. What we find in meteorites

shows that the catastrophe which preceded our present

solar system's birth scattered its elemental constitu

ents throughout its domain, and thus when they came to

be gathered up again into planets that these must have

been materially the same. The manner, not the matter,

then, is alone that about which we are concerned.

Now, if the mass of matter gravitating together to

form a planet be sufficient to produce the proper inor
356 MARS AND ITS CANALS chai-. xx.x

ganic conditions, the organic must follow as a matter of

course. That the organic springs from the inorganic

is not only shown by what has taken place on earth,

but is the necessary logical deduction from its decay

back into the inorganic again. As Nageli admirably

observers: "The origin of the organic from the inor

ganic is, in the first place, not a question of experience

and experiment, but a fact deduced from the law of

the constancy of matter and force. If all things in the

material world are causally related, if all phenomena

proceed on natural principles, organisms which are

formed of and decay into the same matter must have

been derived originally from inorganic compounds."

The original oneness of the two, the fact that the

organic sprang from the inorganic, is shown by the

cousinly closeness of the lowest organic with the high

est inorganic substances. The monera are suggestive

of crystals in their uniformity of structure. Both

are homogeneous or approximately so. Again, both

grow by taking from what they come in contact with

that which they find suitable and so add to their body

by homogeneous accretion. Finally, when grown too

large for single life, they part into similar crystals or

split into identical cells. The difference between the

division of the crystal and the fission of the cell is

small in kind ; much less than that later differentiation

in genesis into parthenogenesis and sexual reproduc
CHAP. XXIX LIFE 357

tion. Yet here we unhesitatingly trace an assured re

lationship. It were straining at a gnat to swallow a

camel to doubt it in the other.

Just as the two behave analogically alike in their

own action, so do they observe a like attitude toward

nature. They thus point to their common origin.

The monera are resemblant of chemical compounds in

their superiority to external influences. To outward

conditions of temperature and humidity the chromacea

are much as sticks and stones. Some species may re

main for long frozen in ice, Haeckel observes, and yet

wake to activity so soon as it thaws. Others may be

completely desiccated, and then resume their life when

put in water after a lapse of several years. Thus both

in their deathlike lives and in their living immortality

the chromacea are close to inorganic things.

From preference, however, these lowest forms of life

affect what to us would be unbearable temperatures.

Many of the chromacea live in hot springs at tempera

tures of 123° to 176° Fahrenheit, in which no other,

that is, no higher, organism can dwell. This choice of

habitat is in line with the" other details of their evolu

tionary career. For it, too, is in keeping with the con

ditions of crystalline growth, halfway as it were on the

road to them; the forming of crystals beginning at a

temperature higher still. And we perceive from it

that the passing of the inorganic into the organic is
358 MARS AND ITS CANALS CHAP. XXIX

brought about by a lowering of the temperature of the

parent planet. This again, is in line with the evolu

tion of chemical complexity. Let the heat become less,

and higher and higher chemical compounds, finally

the organic ones, become possible. That evolution is

nothing else than such a gradually increasing chemical

synthesis is forced on one by study of the facts. Once

started, life, as paleontology shows, develops along

both the floral and the faunal lines side by side, taking

on complexity with time. It begins so soon as secular

cooling has condensed water vapor to its liquid state;

chromacea and conferva? coming into being high up

toward the boiling-point. Then, with lowering tem

perature come the seaweeds and the rhizopods, then

the land plants and the lunged vertebrates. Hand in

hand the fauna and flora climb to more intricate per

fecting, life rising as temperature lowers.

We perceive then that, considered a priori, the possi

bility of life on a planet is merely a question of the

planet's size; and then pursuantly that the character

of that life is a matter of the planet's age. But age

again is a question of size. For the smaller its mass the

quicker the body cools, and with a planet, growing cold

means growing old. ^'ithin the bounds that make life

possible, the smaller the body the quicker it ages and

the more advanced its denizens must be. Just how far

the advance goes we may not assert dogmatically in
CHAP. XXIX LIFE 359

a given case, since not relative age alone but absolute

time as well is concerned in it. It may be that nature's

processes cannot be hurried, and that for want of time

development may in part be missed. But from general

considerations the limit of the time needed seems well

within most planetary careers.

Now, the aspect of the surface of Mars shows that

both these conditions have been fulfilled. Mars is

large enough to have begotten vegetation and small

enough to be already old. All that we know of the

physical state of the planet points to the possibility

of both vegetal and animal life existing there, and fur

thermore, that this life should be of a relatively high

order is possible. Nothing contradicts this, and the

observations of the last ten years have rendered the

conclusion then advanced only the more conclusive.

Even the evidence of the past state of the planet con

firms that given by its present one. That with us life

came out of the seas finds its possible parallel in the

fact that seas seem once to have existed there, leaving

their mark discernible to-day. Life, then, had there as

here the wherewith to begin. That we find air and

water in both shows that it had the means to continue

once begun. That it then ran a like course is further

witnessed by what we now detect. The necessary

premises, then, are there. More than this. One half

of the conclusion, vegetal life, gives evidence of itself.
CHAPTER XXX

EVIDENCE

F the existence of animal life upon a far planet

any evidence must, of necessity, assume a differ

ent guise from what its flora would present. Plant life

should be, as on Mars we perceive it is, recognizable

as part and parcel of the main features of the planet's

face. In no such forthright manner could we expect

an animal revelation. The sort of testimony which

would render the one patent would leave the other

obstinately hid.

So long as animate life was in the lowest sense ani

mal, it would not be seen at all, though it were as wide

spread as the vegetal life all about it. Reason for this

lies in their receptive character. Plants are fixtures;

where they start they stay; while from the nature of

their food, derived directly from the soil and from the

air, and conditioned chiefly by warmth and moisture,

like forms inhabit large areas and by their massed effect

make far impression. With animals it is otherwise.

They feed by forage, from beetle to buffalo, roaming the

land for sustenance. Thus, both for paucity of number

and from not abiding in one stay they must escape notice

;st30
CHAP. XXX EVIDENCE 361

at a distance such that as individuals they fail to show ;

to say nothing of the fact that the flora usually overtop

the fauna, and so help to hide the latter while appear

ing itself distinct. Any far view of our earth gives in

stance of this. Seen from some panoramic height,

forest and moorland lie patently outspread to view, yet

imagination is taxed to believe them tenanted at all.

Unless man have marred the landscape not a sign

appears of any living thing. One must be near indeed

to note even such unusual sights as a herd of buffalo

in the plains or those immense flights of pigeons, that

in former years occurred like clouds darkening the air.

From the standpointof another planet, through any such

direct showing animal existence would still remain un

known.

Not until the creatures had reached a certain phase

in evolution would their presence become perceptible;

and not then directly, but by the results such presence

brought to pass. Occupancy would be first evidenced

by its imprint on the land ; discernible thus initially

not so much by the bodily as by the mind's eye. For

not till the animal had learnt to dominate nature and

fashion it to his needs and ends would his existence

betray itself. By the transformation he wrought in

the landscape would he be known. It is thus we

should make our own far acquaintance; and by the

disarrangement of nature first have inkling of man.
362 MARS AND ITS CANALS chap, xxx

That it is thus we should betray ourselves, a consider

ation of man's history will show. While he still re

mained of savage simplicity, a mere child of nature, he

might come and go unmarked by an outsider, but so

soon as he started in to possess the earth his handicraft

would reveal him. From the moment he bethought

him to till the ground, he entered upon a course of

world-subjugation of which we cannot foresee the end;

but he has already advanced far enough to give us an

idea of the process. It began with agriculture. De

forestation with its subsequent quartering of crops

signalized his acquisition of real estate. His impress

at first was sporadic and irregular, and in so far fol

lowed that of nature itself ; but as it advanced it took

on a methodism of plan. Husbandry begot thrift,

and augmented wants demanded an increasing return

for toil ; and to this desirable end systematization be

came a necessity. At the same time gregariousness

grew and still further emphasized the need for economy

of space and time. In part unconsciously, man learnt

the laws that govern the expenditure of force and more

and more consciously applied them. Geometry, un

loosed of Euclid, became a part of everyday life as in

sidiously as M. Jourdain found that he had been talking

prose. Regularity rules to-day, to the lament of art.

The railroad is straighter than the turnpike, as that is

straighter than the trail. Communication is now too
CHAP. XXX EVIDENCE 363

urgent in its demands to know anything but law and

take other than the shortest path to its destination.

Tillage has undergone a like rectification. To one used

to the patchwork quilting of the crops in older lands

the methodical rectangles of the farms of the Great

West are painfully exact. Yet it is more than probable

that these material manifestations would be the first

signs of intelligence to one considering the earth from

far. Our towns would in all likelihood constitute the

next ; and, lastly, the great arteries of travel that min

ister to their wants. Their scale, too, would render

them the first objects to be observed. Farming as now

practiced in Kansas or Dakota gives it a certain cosmical concern ; fields for miles turning in hue with the

rhythm of the drilled should impress an eye, if armed

withEvenournow appliances, we should manyknowmillions ourelves of miles cosmically away. by

our geometrical designs. To interplanetary under

standing it is this quality that would speak. Still more

so will it tell as time goes on. As yet we are but at the

beginning of our subjugation of the globe. We have

hardly explored it all, still less occupied it. When we

do so, and space shall have become enhancedly precious,

directness of purpose with economy of result will have

partitioned so regularly the surface of the earth as to

impart to it an artificiality of appearance, and it becomes

one vast coordinated expanse subservient entirely to
364 MARS AND ITS CANALS CHAP. XXX

the wants of its possessors. Centres of population

and lines of communication, with tillage carried on in

the most economic way ; to this it must come in the

end.

Nor is this outcome in any sense a circumstance acci

dental to the earth ; it is an inevitable phase in the evo

lution of organisms. As the organism develops brain

it is able to circumvent the adversities of condition;

and by overcoming more pronounced inhospitality of

environment not only to survive but spread. Evi

dence of this thought will be stamped more and more

visibly upon the face of its habitat. On earth, for

all our pride of intellect, we have not yet progressed

very far from the lowly animal state that leaves no rec

ords of itself. It is only in the last two centuries that

our self-registration upon our surroundings has' been

marked. With another planet the like course must in

all probability be pursued, and the older the life rela

tively to its habitat the more its signs of occupation

should show. Intelligence on other worlds could then

only make its presence known by such material revela

tion, and the sign-manuals of itself would appear more

artificial in look as that life was high in rank. Given

the certainty of plant-life, such markings are what one

would look to find. Criticism which refuses to credit

detail of the sort because too bizarre to be true writes

itself down as unacquainted with the character of the
CHAP. XXX EVIDENCE 365

problem. For it is precisely such detail which should

show if any evidence at all were forthcoming.

If, now, we turn our inquiry to Mars, we shall be

fairly startled at what its disk discloses. For we find

ourselves confronted in the canals and oases by pre

cisely the appearances a priori reasoning proves should

show were the planet inhabited. Our abstract prog

nostications have taken concrete form. Here in these

rectilineal lines and roundish spots we have spread out

our centres of effort and our lines of communication.

For the oases are clearly ganglia to which the canals

play the part of nerves. The strange geometricism

which proves inexplicable on any other hypothesis now

shows itself of the essence of the solution. The ap

pearance of artificiality cast up at the phenomena in

disproof vindicates itself as the vital point in the whole

matter. Like the cachet of an architect, it is the thing

about the building that established the authorship.

Though the Earth and Mars agree in being planets,

they differ constitutionally in several important re

spects. Even to us the curious network that en

shrouds the Martian disk suggests handicraft ; it

implies it much more when considered from a Martian

standpoint.
CHAPTER XXXI

THE HUSBANDING OF WATER

^T^HAT the canals and oases are of artificial origin

is thus suggested by their very look; when we

conic to go further and inquire into what may be their

office in the planet's economy, we find that the idea in

addition to its general probability now acquires par

ticular support. For this we are indebted in part to

study of their static aspect, but chiefly to what has

been learnt of their kinematic action.

Dearth of water is the key to their character. Water

is very scarce on the planet. We know this by the

absence of any bodies of it of any size upon the surface.

So far as we can see the only available water is what

comes from the semi-annual melting at one or the other

cap of the snow accumulated there during the previous

winter. Beyond this there is none except for what

may be present in the air. Now, water is absolutely

essential to all forms of life; no organisms can exist

without it.

But as a planet ages, it loses its oceans as has before

been explained, and gradually its whole water supply.

Life upon its surface is confronted by a growing scarcity

WW!
chap, xxxi THE HUSBANDING OF WATER 367

of this essential to existence. For its fauna to survive

it must utilize all it can get. To this end it would be

obliged to put forth its chief endeavors, and the out

come of such work would result in a deformation of the

disk indicative of its presence. Lines of communica

tion for water purposes, between the polar caps, on the

one hand, and the centres of population, on the other,

would be the artificial markings we should expect to

perceive.

Now, it is not a little startling that the semblance of

just such signs of intelligent interference with nature is

what we discern on the face of Mars, — in the canals

and oases. So dominant in its mien is the pencil-like

directness of the canals as to be the trait that primarily

strikes an unprejudiced observer who beholds this as

tounding system of lines under favorable definition

for the first time, and its impressiveness only grows

on him with study of the phenomena. That they

suggested rule and compass, Schiaparelli said of them

long ago, without committing himself as to what they

were. In perception the great observer was, as usual,

quite right ; and the better they are seen the more they

justify the statement. Punctilious in their precision,

they outdo in method all attempts of freehand drawing

to copy them. Often has the writer tried to represent

the regularity he saw, only to draw and redraw his lines

in vain. Nothing short of ruling them could have
308 MARS AND ITS CANALS CHAP. XXXI

reproduced what the telescope revealed. Strange

as their depiction may look in the drawings, the

originals look stranger still. Indeed, that they should

look unnatural when properly depicted is not unnatural

if they are so in fact. For it is the geodetic precision

which the lines exhibit that instantly stamps them

to consciousness as artificial. The inference is so

forthright as to be shared by those who have not

seen them to the extent of instant denial of their

objectivity. Drawings of them look too strange to be

true. So scepticism imputes to the draughtsman

their artificial fashioning, not realizing that by so doing

it bears unconscious witness to their character. For

in order to disprove the deduction it is driven to deny

the fact. Now the fact can look after itself and will

be recognized in time. For that the lines are as I have

stated is beyond doubt. Each return of the planet

shows them more and more geometric as sites are

bettered and training improves.

Suggestive of design as their initial appearance is,

the idea of artificiality receives further sanction from

more careful consideration, even from a static point

of view, on at least eight counts : —

1. Their straightness ;

3.2 Their individually extreme tenuity; uniform size ;

I. The dual character of some of them ;
chap, xxxi THE HUSBANDING OF WATER 369

5. Their position with regard to the planet's funda

mental 6. Their features; relation to the oases ;

7. The character of these spots; and, finally,

8. The systematic networking by both canals and

spots of the whole surface of the planet.

Now, no natural phenomena within our knowledge

show such regularity on such a scale upon any one of

these eight counts, a fortiori upon all. When one con

siders that these lines run for thousands of miles in an

unswerving direction, as far relatively as from London

to Bombay, and as far actually as from Boston to San

Francisco, the inadequacy of natural explanation

becomes glaring.

These several counts become more expressive of de

sign the farther one looks into them. Straightness

upon a sphere means the following of an arc of a great

circle. The lines, then, are arcs of great circles. Now,

the great circle course is the shortest distance connect

ing two given points. The canals of Mars, then, prac

tice this economy; they connect their terminals by

the shortest, that is, other things equal, by the quick

est and least wasteful path. Their preserving a uni

form width throughout this distance is an equally un

natural feature for any natural action to exhibit, but

a perfectly natural one for an unnatural agent. For

means of communication for whatever cause would

2b
370 MARS AND ITS CANALS chap, xxxi

probably be fashioned of like countenance throughout.

Their extreme tenuity is a third trait pointing to ar

tificiality; inasmuch as the narrower they are, the

more probable is their construction by local intelli

gence. Even more inexplicable, except from intent,

is their dual character. For them to parallel one

another like the twin rails of a railway track, seems

quite beyond the powers of natural causation. Enig

matic, indeed, from a natural standpoint, they cease

to be so enigmatic viewed from an artificial one; and

this the more by reason of what has lately been learnt

of the character of their distribution. That they are

found most plentifully near the equator, where the lati

tudinal girth is greatest, and thence diminish in num

bers to about latitude 60°, where they disappear, —

and this not relatively to the amount of surface but

actually, — is very significant. It is quite incapable of

natural explanation, and can only be accounted for

on some theory of design such as lines of communica

tion, or canals conducting water down the latitudes for

distribution. So that this distribution of the doubles

is in keeping with the law of development disclosed

by the canals en masse. Channels and return-channels

the two lines of the pair may be, but about this we can

at present posit nothing. The relation may be of

still greater complexity, and we must carefully dis

tinguish between surmise and deduction.
chap, xxxi THE HUSBANDING OF WATER 371

The position of the canals, with regard to the main

features of the disk, has a cogency of its own, an argu

ment from time. The places from which the lines start

and to which they go are such as to imply a dependence

of the latter upon the former chronologically. The

lines are logically superposed upon the natural features;

not as if they had grown there, but as if they had been

placed there for topographic cause. Those termini

are used which we should ourselves select for stations

of intercommunication. For the lines not only leave

important geodetic points, but they travel directly

to equally salient ones.

The connection of the canals with the oases is no less

telltale of intent. The spots are found only at junc

tions, clearly the seal and sanction of such rendezvous.

Their relation to the canals that enter them bespeaks

method and design. Centring single lines, they are

inclosed by doubles, a disposition such as would be

true did they hold a pivotal position in the planet's

economy.

The shape of the oases also suggests significance.

Their form is round, a solid circle of shading of so deep

a tone as to seem black, although undoubtedly in truth

blue-green. Now, a circular area has this peculiar

property, that it incloses for a given length of perimeter

the maximum of space. Any other area has a longer

inclosing boundary for the surface inclosed. Con
372 MARS AND ITS CANALS CHAP. XXXI

sidering each area to be made up of onion-like envelops

to an original core, each similar in shape to the kernel,

we see that the property in question means that the

average distance for points of the circular area from

the centre is less than the same distance for those of

any other figure. This has immediate bearing on the

possible fashioning of such areas. For sufficient intelli

gence in the fashioners would certainly lead to a con

struction, where the greatest area could be attended to

at the least expenditure of force. This would be where

the distance to be traveled from the centre to all the

desired points was on the average least ; that is, the

area would be round.

But last and all-embracing in its import is the system

which the canals form. Instead of running at hap

hazard, the canals are interconnected in a most remark

able manner. They seek centres instead of avoiding

them. The centres are linked thus perfectly one with

another, an arrangement which could not result from

centres, whether of explosion or otherwise, which were

themselves discrete. Furthermore, the system covers

the whole surface of the planet, dark areas and light

ones alike, a world-wide distribution which exceeds

the bounds of natural possibility. Any force which

could act longitudinally on such a scale must be limited

latitudinally in its action, as witness the belts of Jupiter

or the spots upon the sun. Rotational, climatic, or
chap, xxxi THE HUSBANDING OF WATER 373

other physical cause could not fail of zonal expression.

Yet these lines are grandly indifferent to such compel

ling influences. Finally, the system after meshing the

surface in its entirety runs straight into the polar caps.

It is, then, a system whose end and aim is the tap

ping of the snow-cap for the water there semiannually

let loose; then to distribute it over the planet's face.

Function of this very sort is evidenced by the look

of the canals. Further study during the last eleven

years as to their behavior leads to a like conclusion,

while at the same time it goes much farther by reveal

ing the action in the case. This action proves to be

not only in accord with the theory, but interestingly

explanatory of the process.

In the first place, the canals have shown themselves,

as they showed to Schiaparelli, to be seasonal phe

nomena. This negatives afresh the possibility of their

being cracks. But furthermore, their seasonal be

havior turns out to follow a law quite different from

what we know on earth and betokens that they are in

debted to the melting of the polar cap for their annual

growth, even more directly than to the sun, and that

vegetation is the only thing that satisfactorily accounts

for their conduct. But again this is not alL__TJo@ir

time-^jmjckenir^ down the disk, not jmjy_jto^but3^zx!5*^£ singular uniformity equator.

Now, this last fact has^pgculi^r significance.
374 MARS AND ITS CANALS chap, xxxi

So large are the planetary masses that no substance

can resist the strains due to the cosmic forces acting

on them to change their shape till it becomes one of

stable equilibrium. Thus a body of planetary size,

if unrotating, becomes a sphere except for solar tidal

deformation ; if rotating, it takes on a spheroidal form

exactly expressive, as far as observation goes, of the socalled centrifugal force at work. Mars presents such

a figure, being flattened out to correspond to its axial

rotation. Its surface, therefore, is in fluid equilib

rium, or, in other words, a particle of liquid at any

point of its surface at the present time would stay

where it was, devoid of inclination to move elsewhere.

Now, the water which quickens the verdure of the

canals moves from the neighborhood of the pole down

to the equator as the season advances. This it does,

then, irrespective of gravity. No natural force propels

it, and the inference is forthright and inevitable that it

is artificially helped to its end. There seems to be no

escape from this deduction. Water flows only down

hill, and there is no such thing as downhill on a surface

already in fluid equilibrium. A few canals might pre

sumably be so situated that their flow could, by ine

quality of terrane, lie equatorward, but not all. As we

see on the earth, rivers flow impartially to all points of

the compass, dependent only upon unevenness of the

local surface conditions. Now, it is not in particular
chap, xxxi THE HUSBANDING OF WATER 375

but by general consent that the canal system of Mars

develops from pole to equator.

From the respective times at which the minima take

place, it appears that the canal-quickening occupies

fifty-two days, as evidenced by the successive vegetal

darkenings to descend from latitude 72° north to lati

tude 0°, a journey of 2650 miles. This gives for the

water a speed of fifty-one miles a day, or 2.1 miles an

hour. The rate of progression is remarkably uniform ;

and this abets the deduction as to assisted transference.

The simple fact that it is carried from near the pole to

the equator is sufficiently telltale of extrinsic aid, but

the uniformity of the action increases its significance.

But the fact is more unnatural yet. The growth

pays no regard to the equator, but proceeds across it

as if it did not exist into the planet's other hemisphere.

Here is something still more telling than its travel to

this point. For even if we suppose, for the sake of ar

gument, that natural forces took the water down to the

equator, their action must there be certainly reversed

and the equator prove a dead-line to pass which were

impossible.
CHAPTER XXXII

CONCLUSION

r I THAT Mars is inhabited by beings of some sort

or other we may consider as certain as it is

uncertain what those beings may be. The theory of the

existence of intelligent life on Mars may be likened to

the atomic theory in chemistry in that in both we are

led to the belief in units which we are alike unable to

define Both theories explain the facts in their re

spective fields and are the only theories that do, while

as to what an atom may resemble we know as little as

what a Martian may be like. But the behavior of

chemic compounds points to the existence of atoms too

small for us to see, and in the same way the aspect and

behavior of the Martian markings implies the action

of agents too far away to be made out.

But though in neither case can we tell anything of the

bodily form of its unit, we can in both predicate a good

deal about their workings. Apart from the general

fact of intelligence implied by the geometric character

of their constructions, is the evidence as to its degree

afforded by the cosmopolitan extent of the action.

Girdling their globe and stretching from pole to pole,

the Martian canal system not only embraces their

376
CHAP. XXXII CONCLUSION 377

whole world, but is an organized entity. Each canal

joins another, which in turn connects with a third, and

so on over the entire surface of the planet. This con

tinuity of construction posits a community of interest.

Now, when we consider that though not so large as the

Earth the world of Mars is one of 4200 miles diameter

and therefore containing something like 212,000,000

of square miles, the unity of the process acquires

considerable significance. The supposed vast enter

prises of the earth look small beside it. None of them

but become local in comparison, gigantic as they seem

to us to be.

The first thing that is forced on us in conclusion is the

necessarily intelligent and non-bellicose character of

the community which could thus act as a unit through

out its globe. War is a survival among us from savage

times and affects now chiefly the boyish and unthinking

element of the nation. The wisest realize that there

are better ways for practicing heroism and other and

more certain ends of insuring the survival of the fittest.

It is something a people outgrow. But whether they

consciously practice peace or not, nature in its evolu

tion eventually practices it for them, and after enough

of the inhabitants of a globe have killed each other off,

the remainder must find it more advantageous to work

together for the common good. Whether increasing

common sense or increasing necessity was the spur
378 MARS AND ITS CANALS chap. xxxi.

that drove the Martians to this eminently sagacious

state we cannot say, but it is certain that reached it they

have, and equally certain that if they had not they

must all die. When a planet has attained to the age of

advancing decrepitude, and the remnant of its water

supply resides simply in its polar caps, these can only

be effectively tapped for the benefit of the inhabitants

when arctic and equatorial peoples are at one. Differ

ence of policy on the question of the all-important

water supply means nothing short of death. Isolated

communities cannot there be sufficient unto themselves;

they must combine to solidarity or perish.

From the fact, therefore, that the reticulated canal

system is an elaborate entity embracing the whole planet

from one pole to the other, we have not only proof of

the world-wide sagacity of its builders, but a very sug

gestive side-light, to the fact that only a universal ne

cessity such as water could well be its underlying cause.

Possessed of important bearing upon the possibility

of life on Mars is the rather recent appreciation that the

habitat of both plants and animals is conditioned not

by the minimum, nor by the mean temperature of the

locality, but by the maximum heat attained in the re

gion. Not only is the minimum thermometric point

no determinator of a dead-line, but even a mean tem

perature does not measure organic capability. The

reason for this is that the continuance of the species
CHAP. XXXII CONCLUSION 379

seems to depend solely upon the possibility of repro

duction, and this in turn upon a suitable temperature

at the critical period of the plant's or animal's career.

Contrary to previous ideas on the subject, Merriam

found this to be the case with the fauna of the San

Francisco Peak region in northern Arizona. The

region was peculiarly fitted for a test, because

of rising a boreal island of life out of a subtropic sea of desert. It thus reproduced along its

flanks the conditions of climates farther north, altitude

taking the part of latitude, one succeeding another

until at the top stood the arctic zone. Merriam

showed that the existence of life there was dependent

solely upon a sufficiency of warmth at the breeding sea

son. If that were enough the animal or plant propa

gated its kind, and held its foothold against adverse

conditions during the rest of the year. This it did

by living during its brief summer and then going into

hibernation the balance of the time. Nature in short

suspended its functions to a large extent for months

together, enabling it to resurrect when the conditions

turned.

Hibernation proves thus to be a trait acquired by the

organism in consequence of climatic conditions. Like

all such it can only be developed in time, since nature

is incapable of abrupt transition. An animal suddenly

transported from the tropic to a sub-arctic zone will
380 MARS AND ITS CANALS chap, xxxn

perish, because it has not yet learnt the trick of winter

sleeping. While still characterized by seasonal in

somnia it is incapable of storing its energies and biding

its time. But given time enough to acquire the art,

its existence is determined solely by the enjoyment of

heat enough at some season to permit of the vital pos

sibility of reproducing its kind.

Diurnal shutting off of the heat affects the process

but little, provided the fall be not below freezing at the

hottest season. So much is shown by the fauna of our

arctic and sub-arctic zones, but still more pertinently to

Mars by the zones of the San Francisco Peak region,

since the thinner air of altitude, through which a greater

amount of heat can radiate off, is there substituted

for the thicker one of latitudinally equal isotherms.

Here again with the diurnal as before with the seasonal

it is the maximum, not the mean, or, till low, even the

minimum temperature, that tells.

Now, with Mars the state of things is completely in

accord with what is thus demanded for the existence of

life. The Martian climate is one of extremes, where

considerable heat treads on the heels of great cold.

And the one of these two conditions is as certain as the

other, as the condition of the planet's surface shows

conclusively. In summer and during the day it must

be decidedly hot, certainly well above any possible

freezing, a thinner air blanket actually increasing the
CHAP. XXXII CONCLUSION 381

amount of heat that reaches the surface, though affect

ing the length of time of its retention unfavorably.

The maximum temperature, therefore, cannot be low.

The minimum of course is; but as we have just seen,

it is the maximum that regulates the possibility of life.

In spite, therefore, of a winter probably longer and

colder than our own, organic life is not in the least de

barred from finding itself there.

Indeed, the conditions appear to be such as to put a

premium upon life of a high order. The Martian year

being twice as long as our own, the summer is there pro

portionately extended. Even in the southern hemi

sphere, the one where the summer is the shortest, it

lasts for 158 days, while at the same latitudes our

own is but 90 days. This lengthening of the period of

reproduction cannot but have an elevating effect upon

the organism akin to the prolongation of childhood

pointed out by John Fiske as playing so important a

part in the evolution of the highest animals. Day and

night, on the other hand, alternate there with approxi

mately the same speed as here, and except for what is

due to a thinner air covering reproduce our own ter

restrial diurnal conditions, which as we saw are not

inimical to life.

In this respect, then, Mars proves to be by no means

so bad a habitat. It offers another example of how

increasing knowledge widens the domain that life may
382 MARS AND ITS CANALS chap, uxii

occupy. Just as we have now found organic existence

in abyssal depths of sea and in excessive degrees of both

heat and cold, so do we find from exploration of our

island mountains, which more than any other locality

on earth facsimile the Martian surface, its possession

there as well.

Another point, too, is worth consideration. In an

aging world where the conditions of life have grown

more difficult, mentality must characterize more and

more its beings in order for them to survive, and would

in consequence tend to be evolved. To find, therefore,

upon Mars highly intelligent life is what the planet's

state would lead one to expect.

To some people it may seem that the very strange

ness of Martian life precludes for it an appeal to human

interest. To me this is but a near-sighted view. The

less the life there proves a counterpart of our earthly

state of things, the more it fires fancy and piques in

quiry as to what it be. We all have felt this impulse

in our childhood as our ancestors did before us, when

they conjured goblins and spirits from the vasty void,

and if our energy continue we never cease to feel its

force through life. We but exchange, as our years in

crease, the romance of fiction for the more thrilling

romance of fact. As we grow older we demand reality,

but so this requisite be fulfilled the stranger the realiza

tion the better we are pleased. Perhaps it is the more
CHAP. XXXII CONCLUSION 383

vivid imagination of youth that enables us all then to

dispense with the hall-mark of actuality upon our cher

ished visions ; perhaps a deeper sense of our own one

ness with nature as we get on makes us insist upon get

ting the real thing. Whatever the reason be, certain

it is that with the years a narration, no matter how

enthralling, takes added hold of us for being true.

But though we crave this solid foothold for our concep

tions, we yield on that account no jot or tittle of our

interest for the unexpected.

Good reason we have for the allurement we feel

toward what is least like us. For the wider the separa

tion from the familiar, the greater the parallax the new

affords for cosmic comprehension. That which differs

little yields little to the knowledge already possessed.

Just as a longer base line gives us a better measure

of the distance of the sun, so here the more diverse the

aspects, the farther back they push the common start

ing-point and furnish proportionately comprehensive

insight into the course by which each came to be what

it is. By studying others we learn about ourselves,

and though from the remote we learn less easily, we

eventually learn the more. Even on the side, then,

that touches most men, the personal, the strangeness

of the subject should to the far-seeing prove all the

greater magnet.

One of the things that makes Mars of such transcen
384 MARS AND ITS CANALS chap, xxxii

dent interest to man is the foresight it affords of the

course earthly evolution is to pursue. On our own

world we are able only to study our present and our

past ; in Mars we are able to glimpse, in some sort, our

future. Different as the course of life on the two

planets undoubtedly has been, the one helps, however

imperfectly, to better understanding of the other.

Another, more abstract but no less alluring, appeals

to that desire innate in man to know about the cosmos

of which he forms a part and which we call by the name

of science. Study of Mars responds to this craving

both directly by revelation of the secrets of another

world and indirectly by the bearing of what we thus

learn upon our understanding of the laws of the uni

verse. For the facts thus acquired broaden our con

ceptions in every branch of science. Some day our

own geology, meteorology, and the rest will stand in

debted to study of the planet Mars for advance along

their respective lines. Already the most alert of those

professing them are lending ear to information from

this source, and such cosmopolitanism can but increase

as the years roll on. Today what we already know is

helping to comprehension of another world; in a not

distant future we shall be repaid with interest, and

what that other world shall have taught us will re

dound to a better knowledge of our own, and of that

cosmos of which the two form part.

 
 
];
INDEX

Adamas, unmistakable double in 1903, 214. Aeria, white in, 76; ruddy color of, 148. Air (see Atmosphere), 86; necessity of, to life, 166, 167; as important to astronomical calculations, 7. Air-waves, 250, 251, 273. Albedo, low, 162, 167. Alga;, 349. Amenthes, hibernation of, 317-324. Animalcula, in almost boiling geysers, 349. Aonium Sinus, two doubles suspected in, 242. Aquae Calidae, 208, 253, 315. Archaean age of the earth, 132,

133, 138. Areography, 20-31 ;

beginning and progress of, 109; three periods in, 24. Arizona, 16; in desert belt, 13; plateau of, 18. Arnon, convergent double, 240. Artificiality, of canal system, 366, 368, 369, 370, 374; of oases, 366, 371. Ascraeus Lucus, 331; embraced by the double Gigas, 257. Astaboras, connection with Lucus Ismenius, 260-263.

Atmosphere, of Mars, 62, 63, 71, 78, 79, 87; shown to exist, 80, 82, 83, 84, 163, 167; rare, 85, 86, 162, 167; effect on temperature, 80; constituents of, 162, 164, 166, 168. Autumn, length of Martian, in northern hemisphere, 35, 48; in southern, 35, 48. Axial tilt, 34, 36, 55, 155, 161 ;

determinations of, 34, 36, 155; determines character of seasons, 34, 36; effect of, on presentation of arctic and antarctic regions, 70; effect of, on temperature of arctic and temperate regions, 88.

Bacteria, plasm-eating beings, 353. Barometric pressure, 63, 85. Beer, 23, 26, 109. Bilateralism, inherent attribute 208; of canals,

209. Blue band, surrounding polar caps, 39, 40, 42,43,56,61,63,71, 161, 162, 168, 338, 339. Blue-green areas (see Dark Re gions), 32, 67, 163; taken for seas, 110. British Nautical Almanac, 35. Brontes, development of, 304-312. 2 c :iH5
38(3 INDEX

Cambrian era of Earth, 139. Camera, the, 272 ;

advantage of, 273; slower than the eye, 273; stars the peculiar province of, 273, 274. Canals, 11, 32, 163; discovery of, 24, 26; considered straits, 27; regularity of, 28, 29; unnatural in look, 173; manner of introduction of, 174; conditions necessary to seeing of, 174-177, 282, 283; pencil-like lines, 177, 179, 367; definite in direction, 178; name, 180; width of, 179, 180, 182; length of, 183; visible by virtue of length, 181 ;

oddities of, 183; number of, 184 ;

systematic 185, 187-191, arrangement 248; of, 184,

connect with polar caps, 325, 339 , 373; import 373 ; of system of, 338, 372,

intrinsic change in, 283, 284, 337, 338; what they are not, 185-187, 373; zonal distribution of, 188, 189; departure-points, 190 ;

dependent on general topog raphy, 191 ;

of later origin than main fea tures, 191, 247; kinematic character of, 281- 303; effect on, of illumination, 284; drawings coordination consecutive, of,of286numerous data, ; 288, 289 and;

curves Cartouches), of visibility 289, 290;of (see

geometricism polar, 367, 327. 368 ; of, 175, 206, 365,

Canals in the dark regions, 30, 31, 243-248; of the southern hemisphere,

of 245; the northern hemisphere,

detection deprived 246, 247;seas of, 243, of marine 245; charac

partter,of243; canal system, 244, 245,

Caps247. (sec Polar Caps). Carbon dioxide, 39, 161, 164-168. Carbonic era of Earth, 134, 141,

Carets, 142. 265-270; natural formations, 231, 232; form and position of, 266,

reason 267; for shape of, 268 ;

associated with canals, 267,

help269;in solution of riddle, 270 ;

act like oases, 333. Cartouches of the canals, 289-

interpretation 303; of, 291-293, 299- 303, 344-347; arranged by latitudes, 294; showing first frosts, 299; minimum points of, 297, 344; maximum point of, 301 ;

mean canal, 297, 298. Cenozoic times, 144. Cerberus, obliterated by white spot, 75. Change, 4, 281. shown in polar caps, 37 , 338 ;

in 115, blue-green 120, 122-127, areas 113,6 164; 114,

in canals, 168, 169, 205, 283- 285, 314, 337, 338. Chromacea, in 338. oases, 250-252, 352; 330, 331, 337,

plasm-forming beings, 353 ;

close to inorganic things, 357; in hot springs, 357, 358.
INDEX 387

Chryse, 90, 102. Climate, 82-89; one of extremes, 87; temperature, theoretic and ob served, 87; non-glaciation the rule, 88. Clouds, 55, 71, 73, 89, 163, 165, 283, 284; but few exist, 83, 165; none over blue-green areas, 92; of tawny dust color, 106; probably dust storms, 165; prove existence of atmosphere,

Cold,167. 8, 167, 299. Coloe in Palus, connection with double

canals, 257, 258, 263. Color, 74, 148 ;

of Mare Erythraeum, 122. Conferva?, in almost boiling geysers, 349,

Cretaceous 358. era of the earth, 136, 143, 151, 152. Crystals, conditions of formation, 357.

Dana, 131, 139, 140. Dark Regions, 122-125; thought to be seas, 110, 111; named in accordance, 110, 113 ;

change in aspect cast doubt on marine character of, 113, 114; change in, considered seasonal, 115, 120, 127, 163, 164; marine character lost, 30, 115- 118, 163, 164; traversed by permanent lines, 30, 31, 117, 163, 169; vegetation tracts, 119-127, 163, 164, 168, 169, 170; below level of surrounding sur face, 130, 164; former ocean basins, 120, 129,

latitudinal 131; development in, 123, 124, 126, 127.

Dawes, 21, 23, 249, 250, 268. Day, Martian, length of, 34, 160,

Desert166.regions of the earth, 13,

ashelp coorompared 149-155; observatory explain of, 149,withMars, 151; sites, color16,12,of17,13;Mars, 156;

vegetation position due150,to winds, 163; of,in,153,154. 150;154;

Desertism, 16, 89, 153-158. Deserts (see Reddish-ochre re gions) .

Deuteronilus, 259-261. Development latitudinal follows melting law of canals, of,of299,polar 302,caps, 375;

across 302, equator, 338-340;373. 375. Devonian era of the earth, 141. Diaphragm, the great, 265. Diplopia, 196. Djihoun, narrowest embouchure connectiondouble, with of, 219-220; Luci 228-230; Ismenii,

260, 262. Double Canals, first seen by Schiaparelli, 28, 192; two require phenomena impression classes steady of,of,193, 224 definition, 194,; 204;205, 194; 208,

physical 212, 213; bond between the con connection optical not widths situents illusions, theories of, with of, 205,195-203, 226; of, bays, 206,196-203; 232 221-224, 209;;

length sasonal 229, of, 230,change 205; 233; in, 205:

constituents of, 204 ;
388 INDEX

Double Canals, original line of, 216, 217; number of, 205, 209; list of, 210, 211; gemination period of, 212, 213; direction of, 234-236; zonal distribution of, 236-239,

distribution 370; in longitude, 236; tropical phenomena, 239, 240, 241, 242; compared with single canals, 240; convergent, 240; avoid blue-green areas, 241 ;

connect with blue-green areas,

Dust242. storms, 90, 165.

Earth, tilt seasons of axis on,of,35;34;

polar caps of, 38, 41, 44, 45, 51, 54, 69; rainfall on, 79; viewed from space, 340; vegetal quickening opposite to that on Mars, 344. Eccentricity of orbit, effect on seasons, 46, 48, 52. Elevations on limb, 96, 97; measurement of, 98. Elysium, white in, 75, 76. Eocene era of the earth, 144. Eopaleozoic era, 140. Euphrates, 221, 231, 249, 258-261, 266, 267, 316; continuously double, 213; curious relation to the Portus Sigaeus and Phison, 218, 219. Evolution, 362, 366, 367; planetary, 363, 364 ;

advance in, dependent on en vironment, 145, 146. Exploration, polar, 54. Eye,relation to camera, 272-274.

Farms in Kansas and Dakota, 363. Fastigium Aryn, 269; origin of longitudes, 23, 74. Fauna, 361; of northern Arizona, 18; linked with flora, 349, 350, 358. Flagstaff, Arizona, 16. Flammarion, 21, 23, 202. Flora, 361; linked with fauna, 349, 350, 358; fixtures, 360. Focal length, of objective in photographing canals, 275. Franz Joseph Land, 45. Frosts, first arctic, 299, 300, 345; suggestive of, 87.

Galileo, 20, 39. Ganges, 270; peculiar development of, 226- 228; widest double, 228, 229. Gemination, 214-221. seasonal phenomenon, 212, 213. conditioned by convenience, 218-221. Geology, shows the growing of the land, 131-138. Gigas, embracing the Ascraeus Lucus, 257. Gihon, embouchure of, 232. Gravitation, law of, 160. Gravity, effect on atmosphere, 62; force of, on Mars, 63. Green, 21, 23, 24.

Habitabilitv, 159. Haeckel, 352, 353, 357. Haze, at 90,melting 93, 165; of caps, 56, 64-66,

recurrent, 94.
INDEX 389

Heat, 46, 47, 50, 146, 155. Hellas, 81, 90, 91; in winter, 58, 59; ruddy color of, 148. Herschel, Sir W., 34, 37. Hibernation of canals, 313-324, 379. Hiddekel, embouchure of, 232; connection with Luei Ismenii, 260-262. Hippalus, identical with rift, 326, 327. Hoarfrost, 78, 79, 81 ;

at equator, 79; in southern hemisphere, 80, 92. Huyghens, 23, 26, 108.

Ice sheet, effect of, 52. Illumination, oblique, 97; for measuring elevations, 98. Illusion theories of canals, disproved, 293. Image of sun, not reflected from dark areas,

Insolation, 112. 47, 79, 91. Intelligence on other worlds, method of making itself known,

Islands 364.south, 91, 244; effect of, on isothermal lines, 92.

Jamuna, original line of, 216, 217. Jaxaries, polar canal, 328. Jurassic Jupiter, era .33, of372.the earth, 136, 143,

144. Juturna Fons, a square oasis, 263.

Kaiser, 21, 23, 249. Kinetic theory of gases, 83, 146, 147, 164.

Kison, convergent double, 240.

Lacus Hyperboreus, 246. Lampland, 197, 225, 275. Lick Observatory, 100. Life, necessity 17, 166,of167,air 341; and water to,

maximum thin cold airtemperature no bar to, 18;deter

minative of, 19, 378. 380. Life on Earth, 349-353; dependent on conditions, 349- 355, 357, 379, 380. Life on Mars, 169, 376; vegetal, 348, 359; probably 359, 377,of378,high381,order, 382; 348,

evidence of, 360-365. Limb-light, evidence of atmosphere, 84, 162,

Longitudes, 167. origin of, 23, 74. Lowell Observatory, Annals, 31, 81 ;

Bulletin, 201. Lucus Ismenius, 19, 258; only double oasis, 259; association with canals, 260,

Lucus261.Lunae, 330. Lucus Moeris, 208.

Maedler, 21, 23, 26, 109. Mammal, 349. Maps, of Mars, 20-24, 26-29. Marc Acidalium, 115, 242, 246- 252; white in, 80; darker than the Mare Ery- thraeum, 127. Mare Cimmerium, 267. Mare Erythraeum, 113; irregular lines in, 30; in 1903, 122-124; in 1905, 124-126.
390 INDEX

Mare Icarium, 207. Marc Sirenum, 92, 110, 114, 267. Maria, on the moon, 109, 111; not seas, 112, 113; on Mars, 110; not seas, 1 17; •

southern hemisphere, 31. Matter, distribution of, 3.55. Mercator's projection, 22, 344. Merriam, IS, 19, 379. Mesozoic times of the earth, 135, 142, 144, 151. Meteorology of Mars, 63, 93. Moisture, 86, 154. Monera, 349, 357; suggestive of erystals, 356. Months, Martian, different from our own, 36. Mountains, not visible on Mars, 100; measurement of, 97-100; limit of height visible, 100; on Moon, 98, 99.

Naarmalcha, association with Luci Ismenii, 260, 261. Niigeli, 356. Nansen, 54. Naval Observatory at Washing Nectar, ton, 16.

Neopaleozoic shows white,times 59. of the Earth,

Neptune, 140. 33. Nicks in the coastline (see Carets) .

Nilokeras, double, 209; photographed, 225 Nilosyrtis, unlike other canals, 262 Nitio-bacteria, 350, 353. Nitrogen, 83, 164, 166, 341 Nix Olympica, 74, 78. North America, geologic history of, 133-137.

Oases, detected later than canals, 30,

three 249;stages in appearance of, 250-252; number of, 252 ;

kinds of, 252-254, 263; shape of, 253, 371 ;

position of, 254-257, 263; connected with canals, 256, 257, 262, 371; disprove diplopic theory, 258; objectivity of, 263; in dark regions, 163, 244, 263,

kinematic 264; character of, 330-

latitudinal 333; progress of change in oases, 331 ;

evolution of, 331, 332; intrinsic change in, 337, 338; at junction of canals only, 255, 371. Observations, mutual corroboration of, 165,

among 166; mountains, 7. Organic Evolution, origin of, 356. Orology, of Mars, 62. Ovid,xygen,25.83, 164, 166, 167, 341.

Paleozoic times on the Earth,

Permian 135. period, 142. Personal eliminated, equation, 287.

Phenolngical on Earth, Ms, 343. 342; quickening,

Phiton, 221, 231, 249, 258, 266,

continuously connection 267, 316;withdouble, Euphrates 213; and

Portus Sigaeus, 218, 219. Phoenix Lake, 330.
INDEX 391

Photographs of the canals, 225, 275-277. Photography, celestial, 271-277. Physiographic conditions, on Mars, 68, 128. Pickering, W. H., 330. Pwriun, 71. Polar caps, phenomena of, 37, 41, 61 ;

key to comprehension of planet, 37; compared with those of earth, 41, 46; composition of, 39, 161, 168,339; making of new, 94; position of, 68; aspect of, 56, 57; maxima and minima of, 38, 41-44, 47-53, 55-57, 66-68, 162; fission of, 61. Polar seas (see Blue band); fresh water, 162. Poles, Martian, determination of, 36. Pons Hectoris, 78. Portus Sigaeus, nicks in the coastline, 207, 266, 267; embouchure to Phison and Euphrates, 218. Precipitation, 51, 79, 154, 155; effect on glaeiation, 52. Presentation, a, defined, 287, 288. Probability, law of, 160. Projections on the terminator, 77, 81, 96, 100, 104, 165; color of, 102 ;

cause of, 104-107; great one of 1903, 101-104; of 1900, 104. Propontis, the, 242; canals in, 247; oases in, 256. Protonilus, association with Luci Ismenii, 260.

Pseboas Lucus, 207, 250, 253,

anomalous 263; position of, 262.

Quaternary epoch of the Earth, 137.

Reddish-ochre regions, 153, 155; deserts, 149, 156, 163; variations of tint in, 32, 148, 149, 151. Rifts in polar cap, 61-63, 67, 162, 325-329; permanent in place, 61, 62; not depressions, 62, 63, 162; coincide with canals, 326-328; explanation of, 328, 329. Rotation, early noted, 108, 109; how determined, 34; time of, 34, 160; disclosed by markings, 32-34, 108.

Snbaeus Sinus, 23, 207, 268, 269. San Francisco Peaks, 18, 19, 149, 379, 380. Saturn, 33. Scepticism, 27, 28, 204. Schaeberle, 30. Schiaparelli, 11, 15, 21, 23, 24, 26, 27, 29, 30, 31, 34, 68. 74, 75, 81, 114, 115, 120, 121, 173, 177, 186, 192, 212, 217, 221, 247, 249, 265, 282, 313, 314,

Seas 325, (see 337, Dark367, Regions), 373. southern, formerly on92;Mars and the Moon,

internal 129; absorption of, 147. Seasonal inmetabolic, canals, change, 168, 169; 169, 285, 373.

Seasons, like our own, 34, 35, 106; length of, 48, 79, 161; of vegetal growth, 346, 347.
392 INDEX

Secular change, in canals, 314. Silurian era of the Earth, 134, 138,

Sky, 140. blotting out of, 14; measure of extinction of, 16. Sky, Martian, 89; clear, 165. Slipher, 101, 103. Snow, 345 ;

limits of, on Earth and Mars, 108. Solus Lacus, 23, 242. Spring, Martian, 35, 48; haze in, 94. S.S. Challenger, concerning south polar cap of earth, 45. S.S. Pagoda, 45. Subsidiary snow patches, 67, 73. Summer, Martian, length of, 35, 48, 381. Surface, relatively flat, 62, 76, 97, 164; covered by canal network, 243; inclear-cut fluid equilibrium, in good air,374; 258;

indicative of thin air, 162,

Surface 167.features, reality of, proved, 26, 33. Syrtis Major, 22; first marking made out, 23.

Tempe, white in, 77, 80. Temperature, 78, 147, 165, 166; effect on life, 358. Terminator, projections on, 77, 81, 96, 100- 107, 114, 165; depressions on, 164. Terrane, 108, 265. Terraqueousness, shown by earth, 128, 131.

Terrestriality, follows terraqueousness, 129,

earth's 131, 137, oceans144-146; contracting in inevitably, as size, shown131by; 131, Mars146; and the Moon,

as 128, shown130,by131;the geologic his as tory shownof byearth, paleontology, 131-137; 138-

making 144; a better habitat, 145,

Tertiary 146. times of the Earth, 137, 151. Thoth-Nepenthes, peculiar hibernation course of, of, 315-324. 208;

Titan, 305. Triassic era, 136, 142, 152. Trivium Charontis, canals and oases in, 251, 252,

Twilight 256. arc, shows thin air, 85, 162.

Uranus, 33.

Vegetation, 79, 119-127, 163, 166, 169, 301; color of Mare Erythraeum, 122- 126; theory prof of,supported 170; by rifts in

mostpolarsatisfactory cap, 329 ; explanation

of phenomena of canals, 339,

melts two341,seasons snow, 344, 345, 328. of growth 347, 348, of, 373;46

Water, dearth of, 128, 161, 163, 166, 168, 169, 341, 366; loss of, inevitable, 131 ;

speed of flow of, 375; from polar caps, 340, 374.
INDEX 393

Water-vapor, from polar caps, 83; in atmosphere, 162, 168. Weather, 66, 89, 95. Wedge of Casius, 242; canals in, 247; oases in, 251, 252, 256. Welkin, man-manufactured, 13-15. White spots, 32, 165; similar in look to polar caps, 73; location and season of, 74, 76- 79, 80, 81;

White spots, permanency of, 73, 76; indication of temperature, 80, 165. Winds, 154. Winter, Martian, 35, 48. World, Mars another, 4, 5, 169; evolution of a, 16, 128, 131, 155- 158, 358.

Year, of Earth, 35; of Mars, 35, 161.

A COMPENDIUM OF SPHERICAL ASTRONOMY With its applications to the determination and reduction of positions of the fixed stars

By SIMON NEWCOMB

Cloth 8vo $3.00 net

CONTENTS

PART L PRELIMINARY SUBJECTS Chapter I. Introductory. Notes and References. Chapter II. Differences, Interpolation, and Development. Notes and References. Chapter III. Thk Method of Least Souares. Section I. Mean Values of Quantities. II. Determination of Probable Errors. III. Equations of Condi tion. Notes and References.

PART II. THE FUNDAMENTAL PRINCIPLES OF SPHERICAL ASTRONOMY Chapter IV. Spherical Coordinates. Section I. General Theory. II. Prob lems and Applications of the Theory of Spherical Coordinates. Chapter V. The Measure of Time and Related Problems. Section I. Solar and Sidereal Time. II. The General Measure of Time. III. Problems Involving Time. Chapter VI. Parallax and Related Subjects. Section I. Figure and Dimensions of the Earth. II. Parallax and Semi-diameter. Chapter VII. Aberration. Chapter VIII. Astronomical Refraction. Section I. The Atmosphere as a

Refracting Medium. II. Elementary Exposition of Atmospheric Refraction. III. General Investigation of Astronomical Refraction. Notes and Refer ences to Refraction. Chapter IX. Precession and Nutation. Section I. Laws of the Precessional Motion. II. Relative Positions of the Equator and Equinox at Widely Sepa rated Epochs. III. Nutation. Notes and References to Precession and, Nutation.

PART III. REDUCTION AND DETERMINATION OF POSITIONS OF THE FIXED STARS Chapter X. Reduction of Mean Places ok the Fixed Stars from one Epoch tO Another. Section I. The Proper Motions of the Stars. II. Tiig, onometric Reduction lor Precession. III. Development of the Coordinates in the Powers of the l ime. NOtes AND RefereNCes. Chapter XI. Reduction to Apparent Place. Section I. Reduction to Terms of the First Order. II. Rigorous Reduction for Close Polar Stars. III. Prac tical Methods of Reduction. IV. Construction of Tables of the Apparent Places of Fundamental Stars. NOtes AND RefereNCes. Chapter XII. Method of Determining the Positions of Stars by Merid ian Observations. Section I. Method of Determining Right Ascensions. 1 1. The Determination of Declinations. Chapter XIII. Methods of Deriving the Positions and Proper Motions of the Stars from Published Results of Observations. Section I. Historical Review. II. Reduction of Catalogue Positions of Stars to a Homo geneous System. III. Methods of Combining Star Catalogues.

NOTES AND REFERENCES List cf Independent Star Catalogues. Catalogues made at Northern Observatories. Catalogues made at Tropical and Southern Observatories.

APPENDIX Explanation of the Tables of the Appendix. — I. Constants and Formula in Frequent Use. II. Tables Relating to Time and Arguments for Star Reduc tions. III. Centennial Rates of the Processional Motions. IV. Tables and Formulae for the Trigonometric Reduction of Mean Places of Stars. - V. Reduc tion of the Struve,Peters Precessions to the Adopted Values. VI. Conversion of Longitude and Latitude into R. A. and Dec. VII. Refractions. VIII. Co efficients of Solar and Lunar Nutation. IX. Three,place Logarithms and Trigonometrical Functions.

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