PHILOSOPHICAL 
TRANSACTION 
OF THE 
EOYAL SOCIETY 
OF 
LONDON. 
(A.) 
FOR THE YEAR MDCGCLXXXIX. 
VOL. 180. 
PRINTED BY HARRISON AND SONS, ST. MARTIN’s LANE, W.C., 
printers iw Crbhiarg to '§tx Pajistg. 
MDCCCXC. 
