p ■ y ■<- ■ 
PHILOSOPHICAL 
TRANSACTIONS 
OP THE 
ROYAL SOCIETY 
OF 
LONDON. 
FOR THE YEAR MDCCCLXXX1II. 
VOL. 174.—PART II. 
LONDON: 
PRINTED BY HARRISON AND SONS, ST. MARTIN^ LANE, W.C., 
|) antes in (frbinarg to Pa Utajestjr. 
MDCCCLXXXIII. 
