PHILOSOPHIC A L 
TRANSACTION S, 
OF THE 
ROYAL SOCIETY 
O F 
L O N D O N. 
V O L. LXIX. For the Year 1779* 
part n. 
L O N D O N ? 
PRINTED BY J. NICHOLS, SUCCESSOR TO MR* BOWYER | 
FOR LOCKYER DAVIS, PRINTER TO THE ROYAL SOCIETY, 
MDCCLXXX 
