NATURE SERIES 



POPULAR LECTURES 



AND 



ADDRESSES 



BY 



SIR WILLIAM THOMSON, LL.D., F.R.S., F.R.S.E., &c. 



PROFESSOR OF NATURAL PHILOSOPHY JN THE UNIVERSITY OF GLASGOW, AND 

 FELLOW OF ST. PETER*S COLLEGE, CAMBRIDGE 



[ Lord 



IX THREE VOLUMES 

 VOL. III. 



NAVIGATIONAL AFFAIRS 



WITH ILLUSTRATIONS 



H o n to o n 



MACMILLAN AND CO. 



AND NEW YORK 

 1891 



The A' /!>/// of Translation and Reproduction is Reserved 



