

K. 





PHILOSOPHICAL 



TRANSACTIONS 



OF T11E 



ROYAL SOCIETY OE LONDON. 



SERIES A. 



CONTAINING PAPEUS OF A MATHEMATICAL Oil PHYSICAL CHAIlACTElf. 



VOL. 215. 



LONDON: 



PRINTED BY HARRISON AND SONS, ST. MAKTIN's LANE, W.C., 



iit rbiirarjr to %'is 



OCTOBER, 1915. 



