PHILOSOPHICA L 
TRANSACTIONS, 
OF THE 
i 
ROYAL SOCIETY 
O F 
LONDON. 
VOL. LXXI. For the Year 1781, 
PART I. - %, 
C/ifdwaH .sc. 
LONDON, 
SOLD BY LOCKYER DAVIS, AND PETER ELM SLY, 
PRINTERS TO THE ROYAL SOCIETY. 
MDCCLXXXL 
