PHIL OSOPHICAL 
TRANSACT 10 N S 
OF THE 
ROYAL SOCIETY 
OF 
LONDON. 
FOR THE YEAR MDCCCLXXVIII. 
VOL. 169.— PART II. 
L 0 N I) 0 X : 
PRINTED BY HARRISON AND SONS, ST. MARTIN’S LANE, W.O., 
printers in (tDrbinarg to pet Hlajtstg. 
MDCCCLXXI X. 
