Public ledger. [volume] (Memphis, Tenn.) 1865-1893, 1878-01-23
Tag MAariAN 0

The eminent astronomer, Richard
r. Proctor, writes as follows in Bel
gravia:
Probably the most convenient
assumption we can make is that
there may be creatures in a general
respect like ourselves on these
moons Of Mars, but that owing to
the extreme rarity of the atmos-
phere their vital energy is so far re-
duced that they are not more active
than we are, despite the feeble ac-
ton of gravity in the world. The
air must be exceedingly rare, most
certainly, even if the quantity is
proportional to the volumes of
these moons. On this assumption
the quantity Of air is less than the
quantity of terrestrial air as one is
less than 400 times 400 times 400
that is, amounts only to -64,O00,O00
part of the terrestrial air. Being
spread over a surface which is
but 1-l60, 900 of the earth's, it
follows that the quantity of
air above each square mile of
surface is 1-400 part only of the
quantity over each square mile of
our earth's surface. This would be
little enough in all conscience; but
this is not all. For the action of
gravity being, according to our
assumption, only 1000 Of terrestrial
gravity, it follows that the atmos-
pheric pressure, and therefore
density is further reduced in this
degree, giving finally a density
equal only to 1-245, 900 of the
density of our own air. Now, at a
hight Of seven miles where the at
mospheric pressure is reduced to
one-fourth that at the sea level,
men of ordinary consultation would
perish in a few minutes, if not in
stantly. In Uoxwelis ascent to
nearly that hight, Glaisher tainted,
and Coxwell only just had strength
left to draw the valve string with
his teeth (his hands being al
ready ~powerless). Yet at a hight
Of seven miles, the density of
the air is 60, 0 times greater than
that which, according to our very
reasonable assumption, prevails at
the surface of the Marian moons.
We can very well believe, then, that
in whatever way the inhabitants of
these moons may be adapted, cor-
porally and constitutionally for ex-
lstence in their small homes, the
rarity Of the air there must tend to
reduce their vital energy. So hat
we may well imagine that, instead
of being able to leap to a height of
half a mile or over a distance Of
two or three miles, they are not
more active than we are on earth
with six hundred times greater
weight, but a far more effective res
piration, We might, perhaps, go
even further than this, and assume
that, in order to give to the inhabi-
tants of these moons locomotive
powers proportional in the same
way to their own dimensions as
ours are, they must be sup
posed very much smaller than
we are. We might imagine
them in an atmosphere so exceed
ingly attenuated that creatures
which could have vitality enough to
move freely about must be no larger
than flies or ants, and must have
also some such provision as insects
have for more effective respiration.
In this way we might indin the Mar
tian moons a miniature of our own
earth, not only in the proportions
of these worlds themselves, their
lands and seas and atmospheres,
! but also in those of the creatures
living upon. But it would not be
very interesting to consider mere
miniatures of earth, such as the
moons of Mars would thus come to
be regarded. Indeed, in that case,
little more could be said than that
all the relations presented by this
earth were, or might be, represented
in the Marian moons, but on a
greatly reduced scale.