The record-union., 1897-04-19
A MYSTERY OF MARS.
So-Called Canals and Their Apparent
Duplication.
A New Explanation of the Phenome-
non Offered by NJ. Meunier-
Other Scientists Views.


The two mysteries connected with the
planet Mars which have excited the
most interest in the last few years in
Volve the nature of the so-called Ca
mails" and the phenomenon of dupli-
cation. The strange dark lines which
crisscross the orange-colored area of
the planet with geometrical regularity,
and which have a breadth of about
thirty or forty miles, are sometimes
numerous and distinct, while at other
times few and faint. A large number
of canals which have once been OBJ
served. but were utterly invisible few
years later, have subsequently been
seen again in precisely the same place
as before. Hence it has been prac-
ticable to chart and name them for
Identification on all future occasions
when the planet is advantageously
placed for study. The appearance of
second line, of the same general char
acter as the first, parallel Herewith,
and at least 10 or 100 miles away, is of
infrequenr occurrence, and the duration
of the spectacle is comparatively linn
tied. Various theories have been ad-
vanced to explain this "gemination,'
but none of them have yet been ac-
cepted by any considerable number of
astronomers. And now, within a few
days, rev one has been offered.
Whatever may be thought of it's sound
ness. it at least deserves mention as a
contribution to the discussion.
a brief predatory reminder of the ear
ller hypothesis on this subject may
possibly be welcomed by the general
reader. NJ. Doe, of Amberes, Belgium,
denies the objective reality of the gem
ination, and concludes that it is the
vision after attentive observation. NJ.
Daubree regards the twin canals as
deep assures in the Marian crust,
which widen under the influence
of an enlargement experienced by the
planetary globe itself. According to
NJ. Fizeau. they are glacial crevices, the
edges of which produce the illusion Of
two parallel canals Proctor attributes
them to cold, and suggested that gigan-
tic rivers, frozen over and covered with
snow, would have white centers and
black borders resembling the double
canals. Flammarion imagined that
they might be caused by parallel cur
rents of water, in a state of viscosity
kept apart by electric repulsion. Mel
sci suggested that the phenomenon was
an optical one. The vapor arising
from a single canal he thought, might
acquire at an elevation the form of
semi-cylinGer, which in certain cases
would produce a duplication of the
image. Other scientists have asked
whether or not the doubleness might
not be due to a different kind of at
mospheric refraction
The latest explanation comes from
Stanislas Meunier a Well-known
French geologist, who won his doctors
degree in science by a thesis on meteor
ties nearly thirty years ago. He has
conducted the scientific department of
a Paris paper, "L'Opinion Rationale"
for more than a decade. His theory
briefly stated, is that the second line
is shadow, reflected from the surface
of the real canal upon a translucent
cloud sheet suspended above the sur
face of the planet. In support of this
hypothesis he is able to cite a series Of
laboratory experiments, which he pro-
ceeds to describe at length. He says:
Il draw in dull black, upon a level
lines, which represent more or less
faithfully the geographical map of
Mars, and I let fall upon that surface a
ray of light from the sun or any other
conveniently situated source AT the
same moment l place. a few millimetres
in front of the metal surface and par
allel to it, piece of fine and very
transparent muslin, stretched over a
frame Then in succession l see all
the lines and all the spots of the map
spread cut that is, geminate,' because
of the development, at the side of each
one of them, of the shadows thrown
upon the muslin by the light which the
metal reflects"
Subsequently NJ. Meunier took a pol
ished metal sphere, instead of a plane
mirror. as the basis of his experiment.
Upon this surface, as upon the other,
he traced lines and dots in dull black.
A covering of glass was employed TO
support the muslin screen at a slight
distance from the inscribed surface.
Then, when the globe was illuminated
properly. the termination of the mark
ings was again observed. The effect
resenbled the drawings of Schiaparelli.
Terby and others who have drawn
charts of the Marian surface. The
Frenchman proceeds to declare that all
the essential conditions of his test are
repeated on the planet, sunlight being
reflected strongly from the bright con-
tinenta surfaces, and feebly from the
dark areas that have until recently
been considered seas, but are now be-
Heved by a few scientists to be enor-
nous tracts of vegetation. When the
Martian atmosphere is clear" says NJ
Meunier, the effect is hardly percepti-
BILE: but If the surrounding air contains
mist which is transparent to certain
altitude, and then possesses a moder-
ate degree of opacity, there appears, as
in the muslin. visible to an observer
who is placed beyond, the prolongation
of the reflected rays.
This phenomenon Of shadows by re-
fection' cannot be exclusively peculiar
TO Mars; it ought to exhibit itself like
wise above the earth and above Venus
I-pon the moon, for lack of atmosphere
II cannot be verified, which fact ought
to be noted as one more proof of the
absence of any gaseous envelope around
our satellite Schtaparelli has noticed
that at the moment of termination the