PHILOSOPHICAL TRANSACTIONS 
OF THE 
ROYAL SOCIETY OE LONDON. 
Series A, VOL. 212, pp. 205-226. 
ON THE EMISSION VELOCITIES OF PHOTO-ELECTRONS. 
BY 
A. Ll. hughes, M.Sc., B.A., 
RESEARCH SCHOLAR OF EMMANUEL COLLEGE, CAMBRIDGE. 
LONDON: 
PUBLISHED BY THE ROYAL SOCIETY, 
AND SOLD BY HAEKISON AND SONS, ST. MARTIN’S LANE. 
DULAU AND CO., LTD., 37, SOHO SQUARE, W. 
FRIEDLANDEE AND SON, BERLIN. 
1912. 
A 490. 
12 . 8.12 
Price One Shilling and Siaypence. 
