Founded by Richard A. Proctor, 1881. 



With which is incorporated Hardwicke's Science Gossip, and the Illustrated Scientific News. 



A Monthly Record of Science. 



CONDUCTED BY 



Wilfred Mark Webb, F.L.S., and E. S. Grew, M.A. 



Let Knowledge grow from more to more." 



— Tennyson. 



Volume XXXVI, 



New Series, Volume X. 



1913. 



London ; 



Knowledge Publishing Company, Limited, 

 42, Bloomsbury Square, W.C. 



