The Portland daily press., 1894-10-29

largest near the end of the MafGiau
winter and smallest near the end OF sum
mer, though seaons on Mars can haraly
come and go, as in the earth, II tna6
planet has no atmosphere to conserve
and distribute the solar heat. The polar
spots are brilliant white, and are gen
orally thought to be covered with snow
and ice. Curiously. while the north
polar SHOWS cap the exact pole quite con-
centrically, and as far as the S5th paral-
lei of latitude all around, the south clr-
cumpolar SHOWS do not center about the
pole, but around point much removed
from the planets true pole, as much as
deg. in the elder Herschel's time 17s3)
and even 30 deg. as measured by Llnsser
in 1862, but only 8 deg. at the opposition
in 1892, according to Prof. Comstock,
whose observations bring out very,
clearly not only the rapid shrinking OF
the snow-cap-its diameter diminishing
progressive shifting OF its
centers, which would seem to show
an unsymmetrical shrinkage. Evidently
the fluctuations of the polar caps are the
Key to the situation on Mars, and at the
oppositions both of 1892 and 1894 the
southern one has been critically scruti-
nized. The rate of its progressive diml-
mutton is by no means constant, and It's
area, sometimes increasing and again
diminishing, is at other times intersect-
ed by one or more dark narrow mark
ings; naturally interpreted as heavy
falls of snow in the one case, and in the
other as the melting of snow in the polar
valleys. One great rift" of the polar
cap is very conspicuous, and MIR. Lowell
compares it to the appearance of huge
cart track coming down to one over the
snow.n Its breadth he estimates at 220
miles, and its length 1000 Surround
ing this polar cap is narrow, dark line,
nearly uniform in breadth, which is,
Mr.. Lowell surmises, clearly water at
the edge of the melting snow-a polar
sea in short" He says further
YIN 1872, as the snow began to decrease,
long, dark line was observed, at
Atreqiupa, Peru, to make its appearance
III the midst of the cap and then gradu-
ally to grow till it cut the cap in two.
At the corresponding Martian season in
1894 the same dark line was observed at
Flagsaff, Arizona, in the same position.
1t was well placed for observation, and
parently not far from the center of the
snow cap, and increased In width and
length until it opened into the polar sea
in longitude I60 degrees. Later it's OPP
posite end came out in longitude $50 de-
grees. Meanwhile it was spreading even
faster In the middle While it was thus
eating into the snow, some brilliant
ppiHGS, SA1llll& llkc SudISy WtI6 OUSGrVGU
in the snow between it and the outer
edge of the cap, on several successive
mornings. They undoubtedly were the
far-oH glisten of snow slopes. The SUBJ
sequent behavior of the spots from
which they came bore witness to this,
for the rift grew till it formed large
lake in the midst of the snow not far
from the geographical pole. Other riffs
also appeared and ate into the cap, but
the spots that had shone out so brilliant
ly still remained as snow islands, though
daily diminished in size. At last the
smaller of the two chief portions into
which the cap had been split dwindled
entirely away, and the other became
tiny patch eccentrically placed
A recent announcement of Prof. Camp
bell regarding the spectrum of Mars is
decidedly revolutionary. Our only pres
ent means OF finding out whether the
planet has an atmosphere or not is by
means of the spectroscOpe, which, in the
hands of Secci, Higgins Rutherford,
Yogel and Manner, has given certain
evidence of absorption lines III the spect-
rum of Mars not due to our own atmos-
phere; and the inference has always been
irresistible that Mars is surrounded by
a gaseous envelope of sufficient density
to make itself apparent. But, few
mouths ago, Prof. Campbell. embracing
the opportunity when Mars and the moon
We're near together, made Il direct and
critical comparison of the spectra OF.
these two bodies, with the unexpected
result that they appeared alike in every
particular; meaning, of course, that
Mars has no more of an atmosphere than
the moon itself, which has long been
known to he devoid of such an envelope.
Should this startling result be confirmed
by other investigators it's acceptance
would necesSitate an utter change in the
II n i.lfQ of a axVo L.
appearances which the disc of Mars pre-
sents. For example, as the planeJ turns
on it's axis, carrying the spots from the
center to the edge of the disc, they
gradually melt from view. just as they
would if seen through greater thick
ness Of atmosphere. The temporary OBJ
scurations of certain parts of the disc,
frequently observed and satisfa ctorily
attri buted to clouds, will have to be
otherwise accounted for, and the amount
of water must he inappreciable, even
without considering the difficulties of
explaining how that periodic and we'll
esta blished expansion and shrinking of
the polar caps can go on it there is no
atmosphere to act as a medium in the
formation and deposition Of snow.
Prof. Cam Dpell, then, should feel no
disappointment if his announcement
fails to elicit z cordial welcome from
speculators on the climatology of Mars.
But, allowing that the cosmic cnndi-
tions of Mars are still suitable Tor the
existence of water and an atmosphere,
though of no great density, it is an easy
surmise, and one doubtless correct, that
the lighter regions of the planets face
disclosed by the telescope are land and
the darker water. The southern hemis-
phere of Mars, then, is principally water,
and the northern continental land, pre-
cisely as in the case of the earth; but
while, on our globe, the proportion of
and water is about four to eleven, the
surface of Mars shows water and land
in very nearly equal amounts. Only the
darkest of the dark regions may be ac-
tual sea; indeed, M. Niesten thinks those
parts of the planet now and then seen to
be lightly tinted gray may be marshy
lands. But the true aquatic character
of the suspected seas would best be es-
ia blished by watching for tine refie ction
of the solar image from them. M. Flam-
marion has calculated that under favor
able circumstances the sun, thus reflect
ed, ought to shine as a star of the third
but NO such phenomenon
has yet been observed.
M. Flammarion, who has made an ex-
tended study Of the climatology of Mars,
it analogous to that of the
earth. The northern ice-cap is concen-