He was beginning to smile thoughtfully. The ball was not as cold now as it had been and I was holding it in my lap.

“A steam engine does it,” he said, “and a steam turbine. Of course, they’re not very efficient.”

“They work mechanically, too, and only because water expands when it turns to steam.”

“This seems to do it differently,” he said, sipping thoughtfully at his dark-brown martini. “I don’t know exactly how—maybe something piezo-electric about the way its molecules slide about. I ran some tests—measured its impact energy in foot pounds and compared that with the heat loss in BTUs. Seemed to be about 98 percent efficient, as close as I could tell. Apparently it converts heat into bounce very well. Interesting, isn’t it?”

“Interesting?” I almost came flying out of my chair. My mind was beginning to spin like crazy. “If you’re not pulling my leg with this thing, Farnsworth, you’ve got something by the tail there that’s just a little bit bigger than the discovery of fire.”

He blushed modestly. “I’d rather thought that myself,” he admitted.

“Good Lord, look at the heat that’s available!” I said, getting really excited now.

***

Farnsworth was still smiling, very pleased with himself. “I suppose you could put this thing in a box, with convection fins, and let it bounce around inside—”

“I’m way ahead of you,” I said. “But that wouldn’t work. All your kinetic energy would go right back to heat, on impact—and eventually that little ball would build up enough speed to blast its way through any box you could build.”

“Then how would you work it?”

“Well,” I said, choking down the rest of my rum, “you’d seal the ball in a big steel cylinder, attach the cylinder to a crankshaft and flywheel, give the thing a shake to start the ball bouncing back and forth, and let it run like a gasoline engine or something. It would get all the heat it needed from the air in a normal room. Mount the apparatus in your house and it would pump your water, operate a generator and keep you cool at the same time!”

I sat down again, shakily, and began pouring myself another drink.

Farnsworth had taken the ball from me and was carefully putting it back in its padded box. He was visibly showing excitement, too; I could see that his cheeks were ruddier and his eyes even brighter than normal. “But what if you want the cooling and don’t have any work to be done?”