ence, and at the present time we can say that we know
the geography of the Moon as well as, and even better than, that of our
own planet. The heights of all the mountains of the Moon are measured to
within a few feet. (One cannot say as much for the mountains of the
Earth.) The highest are over 7,000 meters (nearly 25,000 feet).
Relatively to its proportions, the satellite is much more mountainous
than the planet, and the plutonian giants are much more numerous there
than here. If we have peaks, like the Gaorisankar, the highest of the
Himalayas and of the whole Earth, whose elevation of 8,840 meters
(29,000 feet) is equivalent to 1/1140 the diameter of our globe, there
are peaks on the Moon of 7,700 meters (25,264 feet), _e.g._, those of
Doerfel and Leibniz, the height of which is equivalent to 1/470 the
lunar diameter.

Tycho's Mountain is one of the finest upon our satellite. It is visible
with the naked eye (and perfectly with opera-glasses) as a white point
shining like a kind of star upon the lower portion of the disk. At the
time of full moon it is dazzling, and projects long rays from afar upon
the lunar globe. So, too, Mount Copernicus, whose brilliant whiteness
sparkles in space. But the strangest thing about these lunar mountains
is that they are all hollow, and can be measured as well in depth as in
height. A type of mountain as strange to us as are the seas without
water! In effect, these mountains of the moon are ancient volcanic
craters, with no summits, nor covers.

At the top of the highest peaks, there is a large circular depression,
prolonged into the heart of the mountain, sometimes far below the level
of the surrounding plains, and as these craters often measure several
hundred kilometers, one is obliged, if one does not want to go all round
them in crossing the mountain, to descend almost perpendicularly into
the depths and cross there, to reascend the opposite side, and return to
the plain. These alpine excursions incontestably deserve the name of
perilous ascents!

No country on the Earth can give us any notion of the state of the lunar
soil: never was ground so tormented; never globe so profoundly shattered
to its very bowels. The mountains are accumulations of enormous rocks
tumbled one upon the other, and round the awful labyrinth of craters one
sees nothing but dismantled ramparts, or columns of pointed rocks like
cathedral spires issuing from the chaos.

As we said, there is no atmospher