PHILOSOPHICAL 



TRANS AC IONS 



OK THE 



ROYAL SOCIETY OF LONDON 



SERIES A. 



CONTAINING 1'APEItS OF A MATHEMATICAL OR PHYSICAL CHARACTER 



VOL. 207. 



rl 



LONDON: 



PRINTED BY HARRISON AND SONS, ST. MARTIN'6 LANE, W.C., 



printers in tfrbinanj to %is Jflnjtslg. 



FEBRUARY, 1908. 



