THE 



popuLAE scie:i^ce 



MONTHLY. 



CONDUCTED BY K L. AND W, J. YOUMANS. 



VOL. XVI. 



NOVEMBER, 1879, TO APRIL, 1S80. 



NEW YORK : 



D. APPLETON AND COMPANY, 



1, 3, AND 5 BOND STREET. 



1880. 



