PHILOSOPHICAL TRANSACTIONS 
OF THE 
EOYAL SOCIETY OF LONDON 
Series A, VOL. 202, pp. 439-458. 
ON THE PHOTO-ELEGTRIC DISCHARGE PROM METALLIC 
SURFACES IN DIFFERENT GASES 
BY 
W. MANSEKGH VARLEY, M.Sc. (Vict.), Ph.D. (Steasburg), B.A. (Cantab.). 
LATE 1851 EXHIBITION RESEARCH SCHOLAR, EMMANUEL COIiLEGE, CAMBRIDGE; 
ASSISTANT PROFESSOR OF PHYSICS AND ELECTRICAL ENGINEERING, HERIOT-WATT COLLEGE, 
EDINBURGH. 
LONDON: 
PUBLISHED FOR THE ROYAL SOCIETY 
BY DULAU AND CO., 37, SOHO SQUARE, W. 
CONTINENTAL AGENTS, MESSRS. FRIEDLANDEE AND SON, BERLIN. 
1903. 
Price One Shilling and Sixpence. 
A 355. 
11.12.03 
