navigation. Why should we scout the dream of visiting other worlds,
which is at least as old as Lucian? Ere long, and perhaps before the
century is out, we shall be flying through the air to the various
countries of the globe. In succeeding centuries what is to hinder us
from travelling through space to different planets?"

_G_. "Quite impossible. Consider the tremendous distance--the lifeless
vacuum--that separates us even from the moon. Two hundred and forty
thousand miles of empty space."

_I_. "Some ten times round the world. Well, is that tremendous vacuum
absolutely impassable?"

_G_. "To any but Jules Verne and his hero, the illustrious Barbicane,
president of the Gun Club."[1]

[Footnote 1: _The Voyage à la Lune_, by Jules Verne.]

_I_. "Jules Verne has an original mind, and his ideas, though
extravagant, are not without value. Some of them have been realised, and
it may be worth while to examine his notion of firing a shot from the
earth to the moon. The projectile, if I remember, was an aluminium shell
in the shape of a conical bullet, and contained three men, a dog or two,
and several fowls, together with provisions and instruments. It was air
tight, warmed and illuminated with coal gas, and the oxygen for
breathing was got from chlorate of potash, while the carbonic acid
produced by the lungs and gas-burners was absorbed with caustic potash
to keep the air pure. This bullet-car was fired from a colossal
cast-iron gun founded in the sand. It was aimed at a point in the sky,
the zenith, in fact, where it would strike the moon four days later,