Evening star. [volume] (Washington, D.C.) 1854-1972, 1906-01-13
CANALS ON MARS
FURTHER PROOF THAT THEY
HAVE ACTUAL FORMATION.
Answer to Suggestion That the Chan
nels Are an Illusion of
Vision.
From the London Times.


channels (canalD on the surface OF the
planet Mars was first described by the
Italian astronomer, G. v. Schiapareui. in
1877. the question OF their character and
even of their real existence has been
keenly debated. On the one hand, they have
been accepted as truly material forma-
tons, and various hypothesis have been
advanced to explain them, such as that they
are waterways connecting with oceans, or
that they consist of lines of vegetation
growing along irrigation works which de-
rive their water from the seasonal melting
OF the polar SHOWS and are the result of
intelligent effort of some sort, or that they
are merely great riffs produced in the globe
by uneven contraction en- cooling On the
other hand, some competent observers have
failed to detect the canal at all, while others
who have succeeded in seeing them have
not agreed with each other in their de-
scriptions of what they saw. In conse-
quence 1t has been suggested that these
canals or channels are of the nature of IL
lusfons or vision, and are not the definite
features that appear on tho drawings, but
rather the result of slight suggestions
made to the eye by more or less irregu-
lar differences In the minute shadings and
color tints on the surface OF the planet"
Flagstaff Observations.
Within the last few months fresh light
has been thrown on the question by a
piece OF work carried out at the Lowell
observatory at Flagstaff, Arizona The OBJ
servers there have always been among the
most successful in seeing and drawing the
canals; and they resolved to supplement
their visual observations by an attempt to
photograph them in the favorable con-
ditlons presented by the planets opposi-
tfon in the spring of this year when 1t
was cOmDarat1yR1v ri a
observatory at Flagstaff enjoys exceptional
advantages for such a task It stands
I,Soo feet above sea level, and therefore
of the atmosphere which accommodate OBJ
servatories at smaller attitudes, and it
possesses the largest glass in the world
mounted at such an elevation. Further,
the air Is intensely dry and it's currents
trouble the image less and produce less
distortion and obliteration of detail than at
lower levels in more humid conditions
without such advantages the undertaking
would be hopeless; even with them it was
one of extraordinary difficulty and delicacy,
and called for numberless precautions.
1t must be remembered that the diameter
of the planet at the time was only some
fifteen seconds OF arc, and that the view of
1t to be obtained even with the largest tele-
scopes in favorable conditions is little, if
any, better than that obtained of the moon
with the naked eye. But to secure the re-
quired definition of detail it was usually
thought necessary at Flagstaff to use only
the central portion Of the twenty four-inch
object glass of the telescope, which accord
ingly was reduced by diaphragm to an eff
fective diameter Of twelve inches; color
screen was employed that allowed only the
yellow and orange rays to pass, and the
tremeiy sensitive plates which had to be
used permitted exposures of only from six
to ten seconds, though during that time the
utmost care had to be exercised to insure
that the telescope followed the planet
smoothly and exactly.
Photographs Show Canals.
The result was that Mr.. Lampland, Prof.
LowelIs assistant at Flagstaff, succeeded
in obtaining in May and June a number of
photographs of the planet at different
stages of rotation, which show canals quite
/ distinctly and even present indications of
the doubling which has been regarded as
still more doubtful than the existence of
the canals themselves. When a series of
these photographs taken on the same night
in close succession is examined, the same
markings are seen to be repeated from one
to another, though naturally some of the
pictures are better than Others: and COM
parison of drawings made of the planets
surface by Prof. Lowell himself at about
the same dates as, though quite indepen-
IDENTIFY OF, the photographs shows a close
correspondence between the two canals
having the same position and direction
being perfectly visible ON both draw
ings and photographs, even to the nm
the eye, however is so much superior to
mat OF the Photographic plate that, al
though some 400 canals and 175 GASES have
been made out by Prof. Lowell himself, the
photographs have so far revealed only
about forty canals and four or five GASES
If 1t be admitted that the Photographic
plate cannot lie and can yield representa-
tfons only of things that have a real OBJ
1ecttve existence, the conclusion to be
drawn from the constancy OF the markings
on the successive photographs of a series
and the correspondence between phofo-
graphs of different series and almost con-
temporaneous drawings by Prof. Lowell
would seem to be that the canals whatever
De their nature and origin, cannot be mere
subjective illusions on the part of certain
observers, but have an actual existence as
material formations on the surface of Mars