SIR ERNEST RUTHERFORD'S RESEARCH

Evening Post, Volume CV, Issue 91, 17 April 1923, Page 7

SIR ERNEST RUTHERFORD'S RESEARCH

12,000 MILES A SECOND.

(FBOH OUR OWN CORRESPONDENT.) LONDON, Bth March. In his second lecture ou "Atoms. as Projectiles," at the Royal Institute, Sir Ernest Rutherford dealt with the effects produced on the outer electrons by atoms I by impacts with, stray electrons ambling along at the comparatively slow speed of about 180 ft Miles a second. H6 introduced Hii; audience to atomic hustlers like the alpha particles which are ejected from radium at 12,000 miles a second. Of incredibly small size, risible only to the mathematical aye of the physicist, these alpha particles, said Sir Ernest, wet* the most concentrated form of energy known, mass for mass millions of times more powerful than the swiftest mechanical ' projectile; but even thesa stupendously energetio projectiles were unable to effect the disruption of the- central nucleus, of the atom, so enormously powerful were the- electrical forces that held its constituents together. But their swift movement through, air and gases—demonstrated by experiments and lantern slides—had an intense ioniaing, or electi-ifying effect, which by special methods could be accurately measured. The varying phenomena produced by the alpha particles, according to the medium through which they moved were clearly demonstrated, the tube throuEh which they passed being alternately filled with air, hydrogen, and carbon dioxide. Tho resulting effects were exceedingly beautiful, as seen on the luminous screen at the end of the tube, and the experiments were loudly applauded by the audience.