"Watch the plate!" shouted Bennie.
And Thornton watched.
For ten or fifteen seconds nothing happened, and then a faint beam of pale lavender light shot out from the capsule, and the metal plate swung away from the incandescent coil as if blown by a gentle breeze.
Almost instantly there was a loud report and a blinding flash of yellow light so brilliant that for the next instant or two to Thornton's eyes the room seemed dark. Slowly the afternoon light regained its normal quality. Bennie relit his pipe unconcernedly.
"That's the germ of the idea," he said between puffs. "That capsule contains a mixture of vapours that give out disintegrating rays when the temperature is raised by thermic induction above six thousand. Most of 'em are stopped by the zirconium atoms in the capsule, which break down and liberate helium; and the temperature rises in the capsule until it explodes, as you saw just now, with a flash of yellow helium light. The rays that get out strike the uranium plate and cause the surface layer of molecules to disintegrate, their products being driven off by the atomic explosions with a velocity about equal to that of light, and it's the recoil that deflects and swings the plate. The amount of uranium decomposed in this experiment couldn't be detected by the most delicate balance—small mass, but enormous velocity. See?"
"Yes, I understand," answered Thornton. "It's the old, 'momentum equals mass times velocity,' business we had in mechanics."
"Of course this is only a toy experiment," Bennie continued. "It is what the dancing pithballs of Franklin's time were to the multipolar, high-frequency dynamo. But if we could control this force and handle it on a large scale we could do anything with it—destroy the world, drive a car against gravity off into space, shift the axis of the earth perhaps!"
It came to Thornton as he sat there, cigarette in hand, that poor Bennie Hooker was going to receive the disappointment of his life. Within the next five minutes his dreams would be dashed to earth, for he would learn that another had stepped down to the pool of discovery before him. For how many years, he wondered, had Bennie toiled to produce his mysterious ray that should break down the atom and release the store of energy that the genii of Nature had concealed there. And now Thornton must tell him that all his efforts had gone for nothing!
"And you believe that any one who could generate a ray such as you describe could control the motion of the earth?" he asked.
"Of course, certainly," answered Hooker. "He could either disintegrate such huge quantities of matter that the mass of the earth would be shifted and its polar axis be changed, or if radioactive substances—pitchblende, for example—lay exposed upon the earth's surface he could cause them to discharge their helium and other products at such an enormous velocity that the recoil or reaction would accelerate or retard the motion of the globe. It would be quite feasible, quite simple—all one would need would be the disintegrating ray."