PHILOSOPHICA L 
TRANSACTION S, 
OF THE 
ROYAL SOCIETY 
O F 
LONDON. 
VOL. LXVIII. For the Year 1778. 
PART II. 
LONDON, 
PRINTED BY J. NICHOLS, SUCCESSOR TO MR. BOWYER ; 
FOR LOCKYER DAVIS, PRINTER TO THE ROYAL SOCIEil. 
MDCCLXXIX. 
