
THE 
PHYSICAL REVIEW 
A JOURNAL OF EXPERIMENTAL AND 
THEORETICAL PHYSICS 
American Physical Society 
WARD L. NICHOL 
ERNEST MERRITT, AND FREDERICK BEDELL 

Twentieth Volume Begins JANUARY 1905 
PUBLISHED MONTHLY ANNUAL SUBSCRIPTION $5.00 
SAMPLE COPY UPON REQUEST 
THE MacMILLAN COMPANY, 
66 FIFTH AVENUE, NEW YORK 
THE AMERICAN JOURNAL OF SCIENCE 
Established by BENJAMIN SILLIMAN in 1818 



The Leading Scientific Journal in the United States 
Devoted to the Physical and Natural Sciences, with special reference to Physics 
and Chemistry on the one hand, and to Geology and Mineralogy on the other. 
Editor: EDWARD S. DANA 
Associate Editors: hoping ne GEORGE L. Se ze TROW BRIDGE 
. G. FARLOW, and WM. M. DAVIS, 
Proressors A. E. VERRILL, HENRY S. WILLIAMS, i E Ya PIRS SSON, of New Ha 
Proressor G. F. RKER, of T Proressor JOSEPH S. AMES, of ossis 
Mr. J. S. DILLER, of Washington 
Two volumes annually, in monthly numbers of about 80 pages. 
This Journal ended its frst series of 50 volu mes as a quarterly in 1845 ; its second nin 
s EN series as a monthly ended Decem 
896. 
ear or 50 re a number, postage prepaid in the United 
Sta o to — subscribers z countries in the P »- Union. A few sets on sale of 
for the wood sud den seri 
THE AMERICAN JOURNAL OF SCIENCE 
NEW HAVEN, CONN. 
