

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

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



The Leading Scientific Journal in the United States = 
a to the Physical and Natural Sciences, with special — to a 
Chemistry on the one hand, and to Geology and ee | other. — 












Editor: EDWARD S. DANA 
Associate Editors; Proressor GEORGE L. L. GOODALE, JOHN TROWBRIDGE, 
RLO and WM. M. DAVIS, of 
Pnorzssons A. E. VERRILL, HENRY S. WILLIAMS, and L. V. PIRSSON, of New Haven; 
Prorsssor G. F. BARKE == of Philadelphia; PROFESSOR JOSEPH S. AMES, ¢ f Baltimore; 
MR. J. S. DILLER, of Washington. 

Two volumes annually, in monthly numbers of about. 8o pages. 2 
This Journal ce rar d volumes sa quare 45 i Ld : 
of 50 volumes as a two-monthly in 1870; its third series as a monthl: " 

Su tion , postage prepaid in the Unite 
States; Tr to ies bi te of countries in the ‚Postal Union. A few sets on sale 
the rst, second, and third series at er Ten-volume index numbers 
for the second and t 

