point of light, and thirty or forty million miles away, especially as
both the earth and planet are in rapid motion. A flying rifle-shot from
a lightning express at a distant swallow would have more chance of
success. If you missed the mark, the projectile would wheel round the
planet, and either become its satellite or return towards the earth like
that of Jules Verne in his fascinating romance."

_I_. "Jules Verne, and other writers on this subject, appear to have
assumed that all the initial effort should come from the cannon. Perhaps
it did not suit his literary purpose to employ any other driving force.
At all events he possessed one in the rockets of Michel Ardan, the
genial Frenchman of the party, which were intended to break the fall of
the projectile on the moon."

_G_. "If I recollect, they were actually fired to give the car a fillip
when it reached the dead-point on its way back to the earth."

_I_. "Even in a vacuum, where an ordinary propeller could not act, the
bullet may become a prime mover, and co-operate with the gun. A rocket
can burn without an atmosphere, and the recoil of the rushing fumes will
impel the car onwards."

_G_. "Do you think a rocket would have sufficient power to be of any
service?"

_I_. "Ten or twelve large rockets, capable of exerting a united back
pressure of one and a half tons during five or six minutes on a car of
that weight at the earth's surface, would give it in free space a
velocity of two miles a second, which, of course, would not be lost by
friction."