PHILOS OPHICA L 
TRANSACTIONS, 
OF THE 
ROYAL SOCIETY 
O F 
LONDON. 
VOL. LXVII. For the Year 1777. 
PART II, 
LONDON, 
PRINTED BY J. NICHOLS, SUCCESSOR TO MR. BOWYER ; 
FOR LOCKYER DAVIS, PRINTER TO THE ROYAL SOCIETY. 
MDCCLXXVIIL 
