PHILOSOPHICAL 
TRANSACTIONS 
OF THE 
ROYAL SOCIETY OF LONDON. 
Series A. 
CONTAINING PAPERS OF A MATHEMATICAL OR PHYSICAL CHARACTER. 
VOL. 208. 
LONDON: 
PRINTED BY HARRISON AND SONS, ST. MARTIN’S LANE, W.C.. 
|3rmifrs in (ajtrbinarg to 'Jjis Utajrsfg. 
October, 1908, 
