PHILOSOPHICAL 
RANSACTION 
OF THE 
ROYAL SOCIETY 
OF 
LONDON. 
FOR THE YEAR MDCCCLXXX. 
VOL. 171. 
LONDON: 
PRINTED BY HARRISON AND SONS, ST. MARTINS LANE, W.C., 
printers iir ©rbitrarg to f cr Pajestg. 
MDCCCLXXXI. 
