doubt clear up this mystery for
us.

[Illustration: FIG. 43.--Chart of Mars.]

As to the inhabitants of Mars, this world is in a situation as
favorable as our Earth for habitation, and it would be difficult to
discover any reason for perpetual sterility there. It appears to us, on
the contrary, by its rapid and frequent variations of aspect, to be a
very living world. Its atmosphere, which is always clear, has not the
density of our own, and resembles that of the highest mountains. The
conditions of existence there vary from ours, and appear to be more
delicate, more ethereal.

There as here, day succeeds to night, spring softens the rigors of
winter; the seasons unfold, less disparate than our own, of which we
have such frequent reason to complain. The sky is perpetually clear.
There are never tempests, hurricanes, nor cyclones, the wind never gets
up any force there, on account of the rarity of the atmosphere, and the
low intensity of weight.

Differing from ours, this world may well be a more congenial
habitation. It is more ancient than the Earth, smaller, less massive. It
has run more quickly through the phases of its evolution. Its astral
life is more advanced, and its Humanity should be superior to our own,
just as our successors a million years hence, for example, will be less
coarse and barbarous than we are at present: the law of progress governs
all the worlds, and, moreover, the physical constitution of the planet
Mars is less dense than our own.

There is no need to despair of entering some day into communication with
these unknown beings. The luminous points that have been observed are no
signals, but high summits or light clouds illuminated by the rising or
setting sun. But the idea of communication with them in the future is no
more audacious and no less scientific than the invention of spectral
analysis, X-rays, or wireless telegraphy.

We may suppose that the study of astronomy is further advanced in Mars
than on the Earth, because humanity itself has advanced further, and
because the starry sky is far finer there, far easier to study, owing to
the limpidity of its pure, clear atmosphere.

Two small moons (hardly larger than the city of Paris) revolve rapidly
round Mars; they are called Phobos and Deimos. The former, at a distance
of 6,000 kilometers (3,730 miles) from the surface, accomplishes its
revolution rapidly, in seven hours, thirty-nine minutes, and thus makes
the entire circle of th