PHILOSOPHICAL 
R A NSACTIONS 
OF THE 
ROYAL SOCIETY 
OF 
LONDON. 
FOR THE YEAR MDCCCLXXX. 
VOL. 171.—PART II. 
LONDON: 
PRINTED BY HARRISON AND SONS, ST. MARTIN’S LANE, W.C., 
printers in (Qrimtarg to fjer Utajestg. 
MDCCCLXXX. 
