visit to one or more of the nearest of them had been my favourite
day-dream. Treasuring every hint afforded by science or fancy that
bore upon the subject, I felt confident that such a voyage would be
one day achieved. Helped by one or two really ingenious romances on
this theme, I had dreamed out my dream, realised every difficulty,
ascertained every factor in the problem. I had satisfied myself that
only one thing needful was as yet wholly beyond the reach and even the
proximate hopes of science. Human invention could furnish as yet no
motive power that could fulfil the main requirement of the
problem--uniform or constantly increasing motion _in vacuo_--motion
through a region affording no resisting medium. This must be a
_repulsive_ energy capable of acting through an utter void. Man,
animals, birds, fishes move by repulsion applied at every moment. In
air or water, paddles, oars, sails, fins, wings act by repulsion
exerted on the fluid element in which they work. But in space there is
no such resisting element on which repulsion can operate. I needed a
repulsion which would act like gravitation through an indefinite
distance and in a void--act upon a remote fulcrum, such as might be
the Earth in a voyage to the Moon, or the Sun in a more distant
journey. As soon, then, as the character of the apergic force was made
known to me, its application to this purpose seized on my mind.
Experiment had proved it possible, by the method described at the
commencement of this record, to generate and collect it in amounts
practically unlimited. The other hindrances to a voyage through space
were trivial in comparison with that thus overcome; there were
difficulties to be surmounted, not absent or deficient powers in
nature to be discovered. The chief of these, of course, concerned the
conveyance of air sufficient for the needs of the traveller during the
period of his journey. The construction of an air-tight vessel was
easy enough; but however large the body of air conveyed, even though