Evening star. [volume] (Washington, D.C.) 1854-1972, 1878-05-25
Mars Little Moons.
THEIR INHABITANTS MUST BE FEEBLE AN
INACTIVE.
CProf. Proctor, in BeTgravia ]

CProf. Proctor, in BeIgravia
Probably the most convenient assumption
general respect like ourselves, on those
moons of Mars, but that, owing to the extreme
rarity OF the atmosphere, their vital energy is
than we are despie the feeble acion Of %raV
ity in their world. The air must be exceed
lngly rare, most certainly, even If the quanti-
ty Is proportioned to the. volumes of these
moons. On this assumption the quantity of
air is less than the quantity of terrestrial as
is less than 400 times 400 times 400-that is, it
amounts only to l6l.OOO,OO0 part of the terres-
trial air.
Being spread over a surface which is but
l-16O,0W of the earth's it follows that the
quantity OF air above each square mile of sur
free is Loo 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 i'm this degree, giving finally
density OF equal only to l-2iO.000 of the dem
Sty of our own air.
Now, at a height of seven miles, where the
atmospheric pressure is reduced TO one fourth
that at the sea level, men of ordinary cOnsti-
tuition would perish in few minutes, if not
instantly. In COxwelrs ascent to nearly that
height, Glaisher tainted, and COXwell only just
had strength left to draw the valve string with
his teeth (his hands being already powerless).
Yet at the height of seven miles, the density
of the air Is $4,000 times greater than that
which. according to our very reasonable as
sumption, prevails at the surface of the Mar
tian moons.
We can very well believe, then, that in
whatever way the Inhabitants of these moons
may be adapted, cOgpOreally and constitution.
ally, for existence in their small homes, the
rarity of the air there must tend to reduce
their vital energy. SO that We may we'll
imagine that, instead of being able to leap to
height of half mile or over a distance of
two or three miles, they are not more active
than we are on earth with 800 times greater
weight, but far more effective respiration
We might, perhaps, 60 even further than this
and assume that, in order to give the inhabi-
tantS OF these moons locomotive powers pro-
pOrtiOned in the same way to their own di-
mansions as ours are, they must be supposed
very much smaller than We are.
We might imagine them in an atmosphere
SO exceedingly 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 Inspiration.
In this way we might find in the Marian
moons miniature of our own earth, not only
in the proportions of these worlds themselves,
but also i'll those of the creatures living upon
them But 1t would not be very interesting to
consider mere miniatures of our earth such as
the moons OF mars would thus come to be re
garded. 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 greatly reduced
scale