PHILOSOPHICAL 
TRANSACTIONS, 
OF THE 
ROYAL SOCIETY 
O F 
LONDON. 
VOL. L XXVII. For the Year 1787. 
PART I. 
Jtntmr /<•' . 
LONDON, 
SOLD BY LOCK.YER DAVIS, AND PETER ELMSLY, 
PRINTERS TO THE ROYAL SOCIETY* 
MDCCLXXXVII. 
