ESTABLISHED BY EDWARD L. YOUMANS. 



THE 



POPTJLAE SCIENCE 



MONTHLY. 



EDITED BT WILLIAM JAY YOUMANS 



VOL. XXXV. 



MAY TO OCTOBER, 1889. 



NEW YORK : 



D. APPLETON AND COMPANY, 



1, 3, and 5 BOND STREET. 



1889. 



