ABSTRACT
IN the summer of 1907, Rutherford moved from Montreal to Manchester. The long path had come to its end, or nearly so for in the years that followed there were the researches of Rutherford and Boltwood on the production of helium by radium and of Rutherford and Robinson on the heating effect and on the value of e/m for the a-particles of radium emanation and of its short-lived products. The source was a short line source of radium emanation, directed along the normal to a crystal face, the isolating stop a circular hole in a lead screen placed at an equal distance on the other side of the crystal. Andrade was given an even more exacting assignment: no one had yet applied the new method of crystal diffraction, which Moseley was using to such good effect in the domain of the soft X-rays, to the more penetrating γ-rays.
