' ( m 20 1891 



SCIENCE 



LEntered at the Post-Offiee of New York, N.Y., as Second-Class Malter.J 



A WEEKLY NEWSPAPER OF ALL THE ARTS AND SCIENCES. 



Eighth Year. 

 Vol. XV. No. 363. 



NEW YORK, January 17, 1890. 



Single Copies, Ten Cents. 

 ^3.50 Per Year, in Advance. 



FIG. I. — EDISON CENTRAL STATION, BROOKLYN, N.Y. (Sie psge 36). 



