The sun. [volume] (New York [N.Y.]) 1833-1916, 1907-07-11

further added TO these similarities, and
consequently TO the interest which the
inhabitants Of the earth, or, speaking
more exactly, astronomers, take In the
planet, as the points Of similarity suggest
that Mars, like the earth, IL inhabited and
that it may yet be possible to add greatly
to u knowledge of Marian geography.
The photographs already taken may
be said 10 furnish evidence Of a still
further similarity of Mars to earth in
providing evidence hat the first Of the
superior planets. like the earth, though
in vastly greater number, has canals, or
channels, as they were called by SCHIA-
PARELLI, who in 1877 first described them.
These canals have been not only a fruit
full source OF conjecture by those whose
imaginations go beyond the observations
and deductions Of astronomers, but the
latter also have made these appearances
a subject for special study for two
decades or more at Flagstaff observatory
with the aid of its fine twenty-four inch
telescope, the largest in the world at
that elevation, 1880 feet above the sea.
Owing also to this height and the ex-
traordinary clearness and dryness of the
atmosphere, the Flagstaff observatory
has long been regarded by astronomers
as the most suitable place to settl", if
possible, the question which has so long
bafled astronomers and divided them
in their opinions, namely, whether in
reality there are such markings, chan
nalo or oanalo an fhn attrcaaA 90 fha
planet. Perhaps there is only one other
spot on the earth that may be said to
have superior atmospheric advantages
over Flagstaff, and that is on the
plateau of the Peruvian Andes, to which
the Lowell expedition was sent with a
view to utilizing the present favorable
season for Marian observations. A tele-
gram of July ? states that Topp of the
expedition cables: Mars canals photo
graphed there by SLIPHER.7
Many competent observers at lower
attitudes and under less favorable condi-
tions have failed to detect anything that
could with reasonable approximation to
certainty be called a canal, while those
who succeeded in discerning such mark
ings differed widely as 20 their number
and location; and hence it was suggested
hat these lines or channels were the
result of slight suggestions made to the
eye by differences in standings and color
tints on the surface of the planet, or pos
sibly to disturbances in the currents of
the atmosphere of the place of the OBJ
server. Such disturbances are admit
tedly less at Flagstaff and in the dry
atmosphere of the Andean observatory
station, and hence what the photographs
reveal at these W favored points OF
observation will be practically conclu-
sive, as there will be in them less oblit-
Grafton of details than elsewhere.
Still, it must he remembered that even
with all these advantages the work of
pho~tographing the canals is exceed
ingly delicate, not only as regards the
color scheme, by which only the vel
low and orange rays are admitted, but
also a. to the exactness and smoothness
with which the telescope follows the
planet. In the photograph process at
Flagstaff last summer to add still further
certainty photographs were taken at diff
ferent stages of rotation, while Professor
LOWELL, either Immediately preceding
or following the Photographic process,
mapped from ocular observations through
the telescope the various canals he could
perceive. The eye, as is well known, is
superior to Photographic plates in defin-
ing. and hence Professor LowELL's draw
ings show some 400 canals or markings
and l75 GASES. while the photographs
disclose only about forty canals and four
or five GASES. The correspondence be-
tween the photographs and the drawings
as to the larger canals does away with
the supposition that the markings are
due to visual suggestion. In view of
results already obtained the photographs
Just taken in the Andes will be awaited
with great interest.
As to what these canals or channels
really are there is still wide room for
conjecture and further research. Some
astronomers regard them as actual water
ways on a comprehensive scale which
would make our greatest canals on earth
seem insignificant in comparison. Some
have suggested that they are merely
tracts Of land, and others still regard
them as lines Of vegetation growing
along great irrigation works, while still
others consider them merely as great
riffs on the surface due to the cooling
and consequent contraction of the planet.
II may now be said that the advocates
of the canal theory. having established
by Photographic proof the existence of
such markings and that they are not
due to visual suggestion, are in the
ascendent. II then remains for astrono-
mers to discover, if possible, what purpose
such canals, il artificial, could serve in
! the Marian economy.