THE 
POPULAR SCIENCE 
REVIEW. 
A QUARTERLY MISCELLANY OF 
ENTERTAINING AND INSTRUCTIVE ARTICLES ON 
SCIENTIFIC SUBJECTS. 
EDITED BY W. S. DALLAS, F.L.S. 
ASSISTANT-SECRETARY OF THE GEOLOGICAL SOCIETY. 
NEW SERIES, VOLUME V. 
(VOLUME XX. OF ENTIRE SERIES.) 
LONDON: 
DAVID BOGUE, 3 ST. MARTIN’S PLACE, TRAFALGAR SQUARE. 
1881 
