# Mars (Lowell)/Chapter 5

V
OASES
I. SPOTS IN THE LIGHT REGIONS
Suggestive of irrigation as the strange network of lines that covers the surface of Mars appears to be, the suggestion takes on more definite shape yet with the last addition to our knowledge of the planet's surface detail,—the recognition of a singularly correlated system of spots.
The canals, as we have seen, are very remarkably attached to one another. Indeed, the manner with which they manage to combine undeviating direction with meetings by the way grows more and more marvelous, the more one studies it. The meeting-places, or junctions, are evidently for something in the constitution of the canals. The crossings, in fact, seem to be the end and aim of the whole system; the canals, but means to that end. So much is at once inferable from the great intrinsic improbability that such crossings can be due to chance.
This inference receives, apparently, striking corroboration when the planet is more minutely ​scanned. For there turns out to be something at these junctions. This something shows itself as a round or oval spot. To such spot, planted there in the midst of the desert at the junction, do the neighboring canals converge.
Dotted all over the reddish-ochre ground of the desert stretches of the planet, the so-called continents of Mars, are an innumerable number of dark circular or oval spots. They appear, furthermore, always in intimate association with the canals. They constitute so many hubs to which the canals make spokes. These spots, together with the canals that lead to them, are the only markings to be seen anywhere on the continental regions. Otherwise the great reddish-ochre areas are absolutely bare; of that pale fire-opal hue which marks our own deserts seen from far.
That these two things,—straight lines and roundish spots,—should, with our present telescopic means, be the sole markings to appear on the vast desert regions of the planet is suggestive in itself.
Another significant fact as to the character of either marking is the manifest association of the two. In spite of the great number of the spots, not one of them stands isolate. There is not a single instance of a spot that is not connected by a canal to the rest of the dark areas. This remarkable inability to stand alone shows ​that the spots and the canals are not unrelated phenomena, for were there no tie between them they must occasionally exist apart.
Nor is this all. There is, apparently, no spot that is not joined to the rest of the system, not only by a canal, but by more than one; for though some spots, such as the Fountain of Youth, have appeared at first to be provided with but a single canal connection, later observation has revealed concurrence in the case. The spots are, therefore, not only part and parcel of the canal system, but terminal phenomena of the same.
In the first place, as I have said, there appears to be no spot that has not two or more canals running to it; in the second place, I find, reversely, that apparently no canal junction is without its spot. Such association is a most tell-tale circumstance. I believe the rule to have no exception. The more prominent junctions all show spots; and with regard to the less conspicuous ones, it is to be remembered that, as the canals are more easy to make out than the spots, the relative invisibility of the latter is to be expected. From which it would seem that the spots are fundamental features of the junctions, and that for a junction to be spotless is, from its very nature, an impossibility.
Next to their regularity of position is to be remarked their regularity of form. Their ​typical shape seems to be circular; for the better the atmosphere, the rounder they look. Under poor seeing they show as irregular patches smooching the disk, much as the canals themselves show as streaks; the spots differing from the canals in being thicker and not so long. As the seeing improves, the patches differentiate themselves into round dots and connecting lines. Such is the shape of the spots associated with single canals; that is, canals not double. In the case of the double canals, the spots look like rectangles with the corners rounded off. One of the most striking of all of them is the Trivium Charontis, which is nearly square.
Now it will be noticed that these shapes are as unnatural as they are definite, and that they all agree in one peculiarity: they are all convex, not concave, to the entering canals. They are not, therefore, mere enlargements of the canals, due to natural causes; for, were the spots enlargements of the canals, at their crossing-points they should be more or less star-shaped, or concave to the canals, whereas they are round, or roundish rectangles,—that is, convex to the same. Such convexity negatives, at the outset, their being purely natural outgrowths of the canals.
The majority of the spots are from 120 to 150 miles in diameter; thus presenting a certain uniformity in size as well as in shape. ​There are also smaller ones, not more than 75 miles across, or less.
To the spot category belong, apparently, all the markings other than canals to be seen anywhere on the continental deserts of the planet, from the great Lake of the Sun, which is 540 miles long by 300 miles broad, to the tiny Fountain of Youth, which is barely distinguishable as a dot. That all are fundamentally of a kind is hinted at by their shape and emphasized by their character, a point to which we shall now come.
To this end, we will start with an account of where and how they begin to show; for, like the canals, they are not permanent markings, but temporary phenomena. It is in the region about the Solis Lacus that they appear first. The Solis Lacus, or Lake of the Sun, is perhaps the most striking marking on Mars. It is an oval spot in lat. 28° S., with its greater diameter nearly perpendicular to the meridians, and encircled by an elliptical ring of reddish-ochre land, which in turn is bordered on the south by the blue-green regions of the south temperate zone. The whole configuration is such as to simulate a gigantic eye which uncannily turns round upon one as the planet slowly revolves. It is so conspicuous a feature of the disk that it has been recognized for a great many years. The resemblance to an eye is further borne out ​by a cordon of canals that surround it on the north. Upon this cordon, composed of the Araxes, the Daemon, and the Agathodaemon, are beaded a number of spots, two of them, the Phoenix and the Tithonius lakes, being conspicuously prominent. Closer scrutiny reveals several more of the same sort, only smaller. These are all interconnected by a network of canals. Now just as it is in this region that the canals first show, so likewise is it here that the spots first make their appearance.
Although it was here that at this last opposition the spots were first seen, it was not here that their character and purpose became apparent. It was not until later in the season, when the Eumenides-Orcus began to give evidence of being yet more peculiarly beaded, that the true nature of the spots suggested itself to me.
The Eumenides-Orcus is a very long and important canal, connecting the Phoenix Lake with the Trivium Charontis. It is so long—3,540 miles from one end of it to the other—that, although it starts in lat. 16° N. and ends in lat. 12° S., it belts the disk not many degrees inclined to the equator. For a great distance it runs parallel to the northern coast of the Sea of the Sirens. From this coast several canals strike down to it; some stopping at it, others continuing on down the disk. Especially is the western end of the sea, called the Gulf of the ​Titans, a point of departure for canals; no less than six of them, and doubtless more, leaving the gulf in variously radiating directions. At the place where these canals severally cross the Eumenides-Orcus, I began in November to see spots. I also saw others along the Pyriphlegethon, an important canal leading in a more northerly direction from the Phoenix Lake; along the Gigas, a great canal running from the Gulf of the Titans all the way to the Lake of the Moon; and along other canals in the same region. I then noticed that the spots to the north of the Solis Lacus region had darkened, since August, relatively to the more southern ones. In short, I became aware both of a great increase in the number of spots, and of an increase in tint in the spots previously seen.
It was apparent that the spots were part and parcel of the canal system, and that in the matter of varying visibility they took after the canals,—chronologically, very closely after them; for a comparison of the two leads me to believe that the spots make their appearance subsequent, although but little subsequent, to the canals which conduct to them.
Furthermore, the spots, like the canals, grow in conspicuousness with time. Now, when we consider that nothing, practically, has changed between us and them in the interval; that ​there has been no symptom of cloud or other obscuration, before or after, over the place where they eventually appear,—we are led to the conclusion that, like the canals, they grow.
Indeed, in the history of their development the two features seem quite similar. Both grow, and both follow the same order and method in their growth. Both are affected by one progressive change that sweeps over the face of the planet from the pole to the equator, and then from the equator toward the other pole. In the case of the southern hemisphere, it is, as we have just seen, the most southern spots, like the most southern canals, that appear first after the melting of the polar snows. Then gradually others begin to show farther and farther north. The quickening of the spots, like the quickening of the canals, is a seasonal affair. But there is more in it than this. It takes place in a manner to imply that something more immediate than the change in the seasons is concerned in it; immediate not in time, but in relation to the result. A comparison of the behavior of three spots—the Phoenix Lake, Ceraunius, the spot at the junction of the Iris and the Gigas, and the Cyane Fons, a spot where the Steropes, a newly found canal, and the Nilus meet—will serve to point out what this something is. The Phoenix Lake lies in lat. 17° S., Ceraunius in lat 12° N., and ​the Cyane Fons in lat. 28° N. In August of last year, the first of these markings was very conspicuous, the second but moderately so, while the third was barely discernible. By November, the Phoenix Lake had become less salient, Ceraunius relatively more so, and the Cyane Fons nearly as evident as Ceraunius had formerly been. In the Martian calendar, the August observation corresponded to our 20th of June, the November one to our 1st of August. All three spots were practically within the equatorial regions. Now, on the Earth, no such marked progression in seasonal change occurs within the tropics. With us, it is to all intents and purposes equally green there the year through. On Mars it is not. Clearly, some more definite factor than the seasons enters into the matter upon our neighbor world.
That this factor is water seems, from the behavior of the blue-green areas generally, to be pretty certain. But just as the so-called seas are undoubtedly not seas, nor the canals water-ways, so the spots are not lakes. Their mode of growth, so far as it may be discerned, confirms this conclusion. Apparently, it is not so much by an increase in size as by a deepening in tint that they gradually become recognizable. They start, it would seem, as big as they are to be, but faint in tone, premonitory shades of their future selves. They then proceed to ​substantialize by darkening in tint throughout. Now, to deepen thus in color with one consent all over would be a peculiar thing for a lake to do. For had the lake appreciable depth to start with, it should always be visible; and had it not, its bed would have to be phenomenally level to permit of its being all flooded at once. If, however, the spots be not bodies of water, but areas of verdure, their deepening in tint throughout is perfectly explicable, since the darkening would be the natural result of a simultaneous growth of vegetation. This inference is further borne out by the fact that to the spot class belong unquestionably those larger oval markings of which the Lake of the Sun is the most conspicuous example. For both are associated in precisely the same manner with the canal system. Each spot is a centre of canal connections in exactly the way in which the Solis Lacus or the Phoenix Lake itself is. But the light coming from the Solis Lacus and the Phoenix Lake showed, in Professor W. H. Pickering's observations, no sign of polarization such as a sheet of water should show, and such as the polar sea actually did show.
When we put all these phenomena together,—the presence of the spots at the junctions of the canals, their strangely systematic shapes, their seasonal darkening, and, last but not least, ​the resemblance of the great continental regions of Mars to the deserts of the earth,—a solution of their character suggests itself at once; to wit, that they are oases in the midst of that desert, and oases not wholly innocent of design, for, in number, position, shape, and behavior, the oases turn out as typical and peculiar a feature of Mars as the canals themselves.
Each phenomenon is highly suggestive considered alone, but each acquires still greater significance from its association with the other; for here in the oases we have an end and object for the existence of canals, and the most natural one in the world, namely, that the canals are constructed for the express purpose of fertilizing the oases. Thus the mysterious rendezvousing of the canals at these special points is at once explicable. The canals rendezvous so entirely in defiance of the doctrine of chances because they were constructed to that end. They are not purely natural developments, but cases of assisted nature, just as they look to be at first sight. This, at least, is the only explanation that fully accounts for the facts. Of course all such evidence of design may be purely fortuitous, with about as much probability, as it has happily been put, as that a chance collection of numbers should take the form of the multiplication table.
In addition to this general dovetailing of ​detail to one conclusion is to be noticed the strangely economic character of both the canals and the oases in the matter of form. That the lines should follow arcs of great circles, whatever their direction, is as unnatural from a natural standpoint as it would be natural from an artificial one; for the arc of a great circle is the shortest distance from one point upon the surface of a sphere to another. It would, therefore, if topographically possible, be the course to take to conduct water, with the least expenditure of time or trouble, from the one to the other.
The circular shape of the oases is as directly economic as is the straightness of the canals; for the circle is the figure which incloses the maximum area for the minimum average distance from its centre to any point situated within it. In consequence, if a certain amount of country were to be irrigated, intelligence would suggest the circular form in preference to all others, in order thus to cover the greatest space with the least labor.
Following is the list of the oases so far discovered:—
* Acherusia Palus
* Aganippe Fons
* Alcyonia
* Ammonium
* Aponi Fons
* Aquae Apollinares
* Aquae Calidae
* Arachoti Fons
* Arduenna
* Arethusa Fons
* Arsia Silva
* Arsine
* Augila
* Bandusiae Fons
* Biblis Fons
* Castalia Fons
* Ceraunius
* Clepsydra Fons
* Cyane Fons
* Ferentinae Lucus
* Fons Juventae
* Gallinaria Silva
* Hercynia Silva
* Hibe
* Hippocrene Fons
* Hipponitis Palus
* Hypelaeus
* Labeatis Lacus
* Lacus Ismenius
* Lacus Lunae
* Lacus Phoenicis
* Lerne
* Lucrinus Lacus
* Lucus Angitiae
* Lucus Feronia
* Lucus Maricae
* Maeisia Silva
* Mapharitis
* Mariotis
* Meroe
* Messeis Fons
* Nitriae
* Nodus Gordii
* Pallas Lacus
* Propontis
* Serapium
* Sirbonis Lacus
* Solis Fons
* Solis Lacus
* Tithonius Lacus
* Trinythios
* Trivium Charontis
* Utopia
II. DOUBLE CANALS
Even more markedly unnatural is another phenomenon of this most phenomenal system, of which almost every one has heard, and which almost nobody has seen,—the double canals.
To see them, however, all that is needed is a sufficiently steady air, a sufficiently attentive observer, and the suitable season of the Martian year. When these conditions are observed, the sight may be seen without difficulty, and is every whit as strange as Schiaparelli, who first saw it, has described it.
​So far as the observer is concerned, what occurs is this: Upon a part of the disk where up to that time a single canal has been visible, of a sudden, some night, in place of the single canals he perceives twin canals,—as like, indeed, as twins, if not more so, similar both in character and in inclination, running side by side the whole length of the original canal, usually for upwards of a thousand miles, of the same size throughout, and absolutely parallel to each other. The pair may best be likened to the twin rails of a railroad track. The regularity of the thing is startling.
In good air the phenomenon is quite unmistakable. The two lines are as distinct and as distinctly parallel as possible. No draughtsman could draw them better. They are thoroughly Martian in their mathematical precision. At the very first glance, they convey, like all the other details of the canal system, the appearance of artificiality. It may be well to state this here definitely, for the benefit of such as, without having seen the canals, indulge in criticism about them. No one who has seen the canals well—and the well is all-important for bringing out the characteristics that give the stamp of artificiality, the straightness and fineness of the lines—would ever have any doubt as to their seeming artificial, however he might choose to blind himself to ​the consequences. An element akin to the comic enters criticism based, not upon what the critics have seen, but upon what they have not. Books are reviewed without being read, to prevent prejudice; but it is rash to carry the same admirable broad-mindedness into scientific subjects.
In detail the doubles vary, chiefly, it would seem, in the distance the twin lines lie apart. In the widest I have seen, the Ganges, six degrees separate the two; in the narrowest, the Phison, four degrees and a quarter,—not a very great difference between the extremes. Four degrees and a quarter on Mars amount to 156 miles; six degrees, to 220. These, then, are the distances between the centres of the twin canals. Each canal seems a little less than a degree wide, or about 30 miles in the narrower instances; in the broader, a little more than a degree, or about 45 miles. Between the two lines, in the cases where the gemination, as it is called, is complete, lies reddish-ochre ground similar to the rest of the surface of the bright regions. Deducting the two half-widths of the bordering canals, we have, therefore, from 120 to 175 miles of clear country between the paralleling lines.
This gemination of a canal is certainly a passing strange phenomenon. Although, in steady air, the observation is not a difficult one, to see ​the region where it occurs minutely enough for a sufficient length of time to mark the details of the process is another matter. I shall here give what I have been able to gather at the last opposition, and shall hope to add to it at the next. One element of mystery may be eliminated at the outset. The process is not so sudden as it seems. It is perceived of a sudden by the observer because of some specially favorable night. But it has been for some time developing. So much is apparent from my observations. Suggestions of duality occurred weeks before the thing stood definitely revealed. Furthermore, the gemination may lie concealed from the observer some time after it is quite complete, owing to lack of favorable atmospheric conditions. For it takes emphatically steady air to see it unmistakably.
The next point is, that the phenomenon is individual to the particular canal. Each canal differs from its neighbor not only in the distance the lines lie apart, but in the time at which duplication occurs. The event seems to depend both upon general seasonal laws governing all the duplications, and upon causes intrinsic to the canal itself. Within limits, each canal doubles at its own good time and after its own fashion. For example, although it seems to be a rule that north and south canals double before east and west ones, nevertheless, of two north ​and south lines, one will double, the other will not, synchronously with a doubling running east and west; the same is true of those running at any other inclination.
Now this shows that the duplication is not an optical illusion at this end of the line; for, by any double refraction here, all the lines running in the same direction over the disk should be similarly affected, which they are not. On the contrary, there will be, say, two cases of doubling in quite different directions coexistent with several single canals that run the same way.
Nor is there any probability of its being a case of double refraction at the other end of the line,—that is, in the atmosphere of Mars; for in that case it is hard to see why all the lines should not be affected, to say nothing of the fact that, to render such double refraction possible, we must call upon a noumenon to help us out, as we know of no substance capable of the quality upon so huge a scale. Furthermore, what is cogent to the observer, though of no particular weight with his hearers, the phenomenon has no look of double refraction. It looks to be, what it undoubtedly is, a double existence.
Strengthening this conclusion is the mode of development of the doubling. This appears to take place in two ways, although it is possible ​that the two are but different instances of one and the same process. Of the first kind, during this last opposition, the Ganges was an example.
The Ganges was in an interesting proto-plasmic condition during the whole of last summer. About to multiply by fission, it was not at first evident how this would take place. Hints of gemination were visible when I first looked at it in August. It showed then as a very broad but not dark swath of dusky color, of nearly uniform width from one extremity to the other, with sides suggestively even throughout. It is probable that they were then, as afterward, parallel, and that the slight convergence apparent at the bottom was due simply to foreshortening. The swath ran thus north-northwest all the way from the Gulf of the Dawn to the Lacus Labeatis. By moments of better seeing, its two sides showed darker than its middle; that is, it was already double in embryo, with a dusky middle-ground between the twin lines.
In October the doubling had sensibly progressed. The double visions were more frequent, and the ground between the twin lines had grown lighter. By November the doubling was unmistakable, and the mid-clarification had become nearly complete. It is to be remarked that the doubling did not involve the Fons Juventae and the canal leading to it, both of ​which lay well to the right of the Ganges. The space included between the East and West Ganges was very wide, some six degrees. The canals themselves were, so far as could be seen, quite similar, and about a degree, or 37 miles, wide. Both started in the Gulf of the Dawn, and ran down to the lower Lake of the Moon, one entering each side of the lake or oasis. Two thirds of the way down, both similarly touched the sides of another oasis, an upper Lacus Lunae; the other I have called the Lacus Labeatis. The length of each canal was 1200 miles.
Except for fleeting suspicions of gemination, and for possible doublings like the parallelism of the two Hades, the next canal to show double was the Nectar, which was so seen by Mr. Douglass on October 4, and under still better seeing, a few minutes later, the doubling was detected by him extending straight across the Solis Lacus. In the Solis Lacus this was evidently a case of mid-clarification. What occurred in the Nectar seems more allied to the second class of manifestations, such as happened later with the Euphrates and the Phison.
Plate XXIII
PHISON AND EUPHRATES (Both double) November 18, 1894
After that evening, whenever the seeing was good enough, they continued to present the same appearance. Now, with them no process of midway clarification, such as had taken place in the Ganges, had previously made itself manifest. They had, indeed, not been very well defined before duplication occurred, but apparently sufficiently so not to hide such broadening had it taken place; for, though the twin canals were not as far apart as the two Ganges, they were quite comparably distant, being, instead of six, about four and a quarter degrees from each other. Evidently, the process was, in the case of the Euphrates at least, under way in October, and even earlier, but was not well seen because the twin canals were not yet dark enough.
There seem, I may remark parenthetically, to be two other double canals in the region between the Syrtis Major and the Sabaeus Sinus, one to the east of the Phison, and another between the Phison and the Euphrates, both debouching at the same points as the Phison and the Euphrates themselves.
​On the 19th of November I suspected duplication in the Typhon, another canal in the same region. It looked to be double, with dusky ground between.
On the 21st I similarly suspected the Jamuna and the Dardanus. Both looked broad and dusky, with very ill-defined condensation at the sides. But the seeing was not good enough. On the 22d I brought my observations to an end, in consequence of having to return East.
Exactly what takes place, therefore, in this curious process of doubling, I cannot pretend to say. It has been suggested that a progressive ripening of vegetation from the centre to the edges might cause a broad swath of green to become seemingly two. There are facts, however, that do not tally with this view. For example, the Ganges was always broad, but fainter, not narrower, earlier in the season. The Phison, on the other hand, went through no such process. Indeed, we are here very much in the dark, certainly very far off from what does take place in Martian canal gemination. Perhaps we may learn considerably more about it at the next opposition. At this the tendril end of our knowledge of our neighbor we cannot expect hard wood.
From these observations, and those of Schiaparelli, I feel, however, tolerably sure that the phenomenon is not only seasonal but vegetal. ​Why it should take this form is one of the most pregnant problems about the planet. For it is the most artificial-looking phenomenon of an artificial-looking disk.
III. SPOTS IN THE DARK REGIONS.
To return now from these outposts of investigation to our main subject-matter, and to another phenomenon of more recent discovery than the double canals, and yet more suggestive of interpretation. We have seen what shows at one end of the canals, their inner end; namely, the oasis. But it seems that there is also something exceptional at the other. At the mouth of each canal, at the edge of the so-called seas, appears a curious dark spot, of the form of a half-filled angle; the sort of a mark with which one checks items on a list. Its form is singularly appropriate, according to mundane ideas, for it appears before the canal itself is visible, as if to mark the spot where the canal will eventually be. It lies in the so-called seas, and looks to be of the same color as they, but deeper in tint.
All the canals that debouch into the dark regions are provided with these terminal triangles, except those that lead out of long estuaries, like the Nilosyrtis, the Hiddekel, the Gihon, and so forth. The double canals are provided with twin triangles. That the triangular patches are phenomena connected with ​the canals is evident from the fact that they never appear elsewhere. What exact purpose they serve is not so clear, but it would seem to be that of relay stations for the water before it enters the canals; what we see, upon this supposition, being, not the station or reservoir itself, but the specially fertile area round it.
That, in addition to being in a way oases themselves, they serve some such purpose as the above, is further hinted at by two facts: first, that whereas the oases develop, apparently, after the canals leading to them, the triangular spots develop before the canals that lead out of them; second, Mr. Douglass finds that it is in them that the canals in the dark regions terminate. They are the end of the one system at the same time that they are the beginning of the other. They would, therefore, seem to be way-stations of some sort on the road taken by the water from the polar cap to the equator.
Paralleling in appearance the oases in the bright regions are round spots that occur at the junctions of the canals in the dark ones. Speaking figuratively, these are the heads of the nails in the coffin of the idea that the seas are seas; since, if the blue-green color came from water, there could not be permanent darker dots upon it connected by equally dark streaks. Speaking unfiguratively, this shows that the whole system of canals and specially fertilized spots is not ​confined to the deserts, but extends in a modified form over the areas of more or less vegetation.
There are thus two kinds of spots in the dark regions: those on their borders, and those in their midst. The position of the former—on the edge of the great deserts—implies a difference in kind, further emphasized by their shape. Following is the list of both kinds detected at Flagstaff:—
SPOTS IN THE DARK REGIONS.
Astrae Lacus. Benacus Lacus. Cynia Lacus. Flevo Lacus. Hesperidum Lacus. Oxia Palus. Spot at the mouth of the Phison. "Euphrates. "Daix on the Mare Icarium. Spot at the mouth of the Daix on the Sabaeus Sinus. Spot on the Socratis Promontorium. Spot on the western side of the Socratis Promontorium. "Margaritifer Sinus. Spot at the mouth of the Jamuna on the Aurorae Sinus. "Ganges" "Hebe" "Agathodaemon" "Ambrosia on the Mare Australe. "Maeander on the Aonius Sinus. "Gorgon on the Mare Sirenum. "Erinaeus. "Titan on the Sinus Titanum.
Spot at the mouth of the Cophen on the Mare Cimmerium.
"Laestrygon" "Nereides" "Cerberus"
"Chretes"
"Asopus on the Syrtis Major.
"Arosis" "Typhon"
Spot south of the mouth of the Typhon"
We thus perceive that the blue-green areas are subjected to the same engineering system as the bright ones. In short, no part of the planet is allowed to escape from the all-pervasive trigonometric spirit. If this be Nature's doing, she certainly here runs her mathematics into the ground.