The Making of the Atomic Bomb: 25th Anniversary Edition

by Richard Rhodes

He announced his recent confirmation, only briefly reported the month before, that the alpha particle was in fact helium.156 The confirming experiment was typically elegant. Rutherford had a glassblower make him a tube with extremely thin walls. He evacuated the tube and filled it with radon gas, a fertile source of alpha particles. The tube was gastight, but its thin walls allowed alpha particles to escape. Rutherford surrounded the radon tube with another glass tube, pumped out the air between the two tubes and sealed off the space. “After some days,” he told his Stockholm audience triumphantly, “a bright spectrum of helium was observed in the outer vessel.” Rutherford’s experiments still stun with their simplicity.157 “In this Rutherford was an artist,” says a former student. “All his experiments had style.”