e what they thought I ought to
have--in ten years or so. Look what happened to Fermi.

"No, Elshawe; when the Government comes begging to me for this
invention, they can have it--on _my_ terms."

"Going to keep it a secret, eh? You can't keep a thing like that secret.
Look what happened with atomic energy after World War Two. We kept it a
secret from the Russians, didn't we? Fine lot of good that did us. As
soon as they knew it was possible, they went to work on it. Nature
answers any questions you ask her if you ask her the right way. As soon
as the Government sees that your spaceship works, they'll put some of
their bright physicists to work on it, and you'll be in the same
position as you would have been if you'd showed it to them in the first
place. Why risk your neck?"

Porter shook his head. "The analogy isn't valid. Suppose someone had
invented the A-bomb in 1810. It would have been a perfectly safe secret
because there wasn't a scientist on Earth who included such a thing as
atomic energy in his philosophy. And, believe me, this drive of mine is
just as far ahead of contemporary scientific philosophy as atomic energy
was ahead of Napoleon's scientists.

"Suppose I told you that the fuel my ship uses is a gas lighter than
hydrogen. It isn't, but suppose I told you so. Do you think any
scientist today could figure out how it worked? No. They _know_ that
there's no such thing as a gas with a lighter atomic weight than
hydrogen. They know it so well that they wouldn't even bother to
consider the idea.

"My invention is so far ahead of present-day scientific thought that no
scientists except myself could have even considered the idea."

"O.K.; O.K.," Elshawe said. "So you're going to get yourself shot down
to prove your point."

Porter grinned lopsidedly. "Not at all. You're still thinking in terms
of a rocket. Sure--if I used a rocket, they'd knock me down fast, just
as soon as I lifted above the mountains. But I don't have to do that.
All I have to do is get a few feet of altitude and hug the ground all
the way to the Pacific coast. Once I get out in the middle of the
Pacific, I can take off straight up without being bothered at all."

"All right. If your machine will do it," the reporter said, trying to
hide his skepticism.

"You still think I've got some kind of rocket, don't you?" Porter asked
accusingly. He paused a moment, then, as if making a sudden decision, he
said: "Look, Elshawe, I trust you. I