"I believe it will teach us far more wonderful things, because it will take us to unknown worlds, while electricity has been confined to Earth. Its realm is the wide universe. It will show us what life there is on the planets. It will make us at home with the stars.
"What!" he continued in a sort of ecstasy. "Do you think all great discoveries are over, all wonderful inventions made? As well might a trembling child, elated with the success of its first feeble steps alone, suppose it had exhausted all the possibilities of life. We are but spelling over the big letters on the title page of the primary book of knowledge. There be other pages and grander chapters further on. There be greater volumes, and sweeter, more expressive tongues which man may learn some day.
"Has a reasoning Divinity created the heavens and peopled the myriad stars with thinking, capable beings, who must be perpetually isolated? Or may they not know each other some time? But shall we attempt to sail the vast heavens with a paper kite, or try to fly God's distances with the wings of fluttering birds? Nay; we must use God's engine for such a task. Has He tied the planets to the sun, and knitted the suns and their systems into one great universe obedient to a single law, with no possibility that we may use that law for intercommunication? With what wings do the planets fly around the sun, and the suns move through the heavens? With the wings of gravity! The same force for minute satellite or mighty sun. It is God's omnipotence applied to matter. Let us fly with that!"
"But will you permit me to suggest that we are soaring before the projectile is built?" I put in.
"Quite right. Let us come back to Earth, and return to facts. My studies in physics led me to believe that all natural forces—gravity, centrifugal force, and even capillary attraction—are, like electricity and magnetism, both positive and negative in their action. If they do not normally alternate between a positive and negative current, as electricity does, they can be made to do so. Gravity and capillary attraction, as we know them, always act positively; that is, they always attract. On the other hand, centrifugal force always acts negatively; that is, it always repels. But each of these forces, I believe, can temporarily be made to act opposite to its usual manner. I know this to be the case with gravity, for I have caused its positive and negative currents to alternate; that is, I have made it repel and then attract, and so on, at will, by changing the polarity of the body which it acts upon."
"Now that I remember it," I added, "our original ideas of magnetism were that it simply attracted. We knew the lodestone drew the steel, but only on better acquaintance did we learn of its alternating currents, attractive and repellant."
"I have positively demonstrated with my working model that I can reverse the force of gravity acting upon the model, and make it sail away into space. I will show you this whenever you like. It is so arranged that the polarizing action ceases in three minutes, after which the positive current controls, and the model falls to the Earth again."
"But have you ever attempted a trip yet?" I inquired.
"Oh, no. The model was not built to carry me, but it has demonstrated all the important facts, and I now need ten thousand dollars to build one large enough to carry several persons, and to equip it with everything necessary to make a trip to one of the planets. With a man inside to control the currents, it will be far more easily managed than the experimental model has been."
"Suppose you had the projectile built, and everything was ready for a start," I said, "what would be the method of working it?"