

PHILOSOPHICAL 



TRANSACTIONS 



OF THE 



ROYAL SOCIETY OF LONDON. 



SERIES A. 



CONTAINING PAPEHS OF A MATHEMATICAL OK PHYSICAL CHAKACTEK. 



VOL. 210. 



LONDON : 



PRINTED BY HARRISON AND SONS, ST. MARTIN'S LANE, W.C., 



IJrinftrs i rbiitarg to fiis ^Tajtsig. 



FEBRUARY, 1911. 



