fic methods, that whatever is
true of one of them, as our earth, will be true of the others (p. 34).
Hence, they are all inhabited by human beings. It is true that human
beings must find Venus rather warm, and are not unlikely to be seriously
incommoded by the tropical climate of Mercury. But we must remember
that "the men of Venus and Mercury are made by nature to resist heat,
as those of Jupiter and Saturn are made to endure cold, and those of the
Earth and Mars to live in a mean temperature: OTHERWISE THEY COULD NOT
EXIST" (p. 72). In view of this charming specimen of a truly scientific
inference, it is almost too bad to call attention to the fact that M.
Figuier is quite behind the age in his statement of facts. So far from
Jupiter and Saturn being cold, observation plainly indicates that they
are prodigiously hot, if not even incandescent and partly self-luminous;
the explanation being that, by reason of their huge bulk, they still
retain much of the primitive heat which smaller planets have more
quickly radiated away. As for M. Figuier's statement, that polar snows
have been witnessed on these planets, it is simply untrue; no such thing
has ever been seen there. Mars, on the other hand, has been observed
to resemble in many important respects its near neighbour, the Earth;
whence our author declares that if an aeronaut were to shoot clear of
terrestrial gravitation and land upon Mars, he would unquestionably
suppose himself to be still upon the earth. For aerolites, it seems, are
somehow fired down upon our planet both from Mars and from Venus; and
aerolites sometimes contain vegetable matter (?). Therefore, Mars has
a vegetation, and very likely its red colour is caused by its luxuriant
autumnal foliage! (p. 47.) To return to Jupiter: this planet, indeed,
has inconveniently short days. "In his 'Picture of the Heavens,'
the German astronomer, Littrow (these Germans think of nothing but
gormandizing), asks how the people of Jupiter order their meals in the
short interval of five hours." Nevertheless, says our author, the
great planet is compensated for this inconvenience by its equable and
delicious climate.

In view, however, of our author's more striking and original
disclosures, one would suppose that all this discussion of the physical
conditions of existence on the various planets might have been passed
over without detriment to the argument. After these efforts at proving
(for M. Figuier presumably regards th