return is a problem of comparatively easy solution: we should have to
overcome the lunar attraction only--a slight matter--the rest of the
business would be readily done by gravity."

"Enough said on the subject!" exclaimed Ardan curtly; "how to get back
is indefinitely postponed! How to communicate with our friends on the
Earth, is another matter, and, as it seems to me, an extremely easy
one."

"Let us hear the very easy means by which you propose to communicate
with our friends on Earth," asked the Captain, with a sneer, for he was
by this time a little out of humor.

"By means of bolides ejected from the lunar volcanoes," replied the
Frenchman without an instant's hesitation.

"Well said, friend Ardan," exclaimed Barbican. "I am quite disposed to
acknowledge the feasibility of your plan. Laplace has calculated that a
force five times greater than that of an ordinary cannon would be
sufficient to send a bolide from the Moon to the Earth. Now there is no
cannon that can vie in force with even the smallest volcano."

"Hurrah!" cried Ardan, delighted at his success; "just imagine the
pleasure of sending our letters postage free! But--oh! what a splendid
idea!--Dolts that we were for not thinking of it sooner!"

"Let us have the splendid idea!" cried the Captain, with some of his old
acrimony.

"Why didn't we fasten a wire to the Projectile?" asked Ardan,