^ 



THE 





;i'i iO 



POPULAE SCIEl^CE 





i; 



©l^THLY. 



<-,^ t\i*% . ;i^ 



CONDUCTED BY E. L. AND W. J. YOUMAJSTS. 



stA}!! ^''^ 



.!r*-/ 





VOL. XXV. 



MAY TO OCTOBER, 1884. 







Vi 



KEW YORK : 

 D. APPLETON AND COMPANY, 



1, 3, AND 5 BOND STREET. 

 1884. 



