572 
PHILOSOPHICAL SOCIETY OF WASHINGTON. 
Mr. J. F. Hayford read two papers; the first, entitled The 
Detection by Azimuth Observations of Variations in the Pole or 
the Vertical, was discussed by Messrs. Bauer, Paul, Kummel, 
Harkness, and Hayford ; the second was entitled A Recent 
Check on the Relation Between the Metric Units of Length and 
Mass. 
Not published. 
378th Meeting. December 19, 1891. 
TWENTY-FIRST ANNUAL MEETING. 
President Mendenhall in the chair. 
Thirty-three members present. 
On motion of Mr. Harkness, it was voted that the officers of 
the Society shall serve to the end of the annual meeting. 
The annual report of the Secretaries was read and accepted. 
ANNUAL REPORT OF THE SECRETARIES. 
Washington, D. C., December 19, 1891. 
To the Philosophical Society of Washington: 
The Secretaries have the honor to submit the following annual 
report for the year 1891: 
The number of active members in the Society at the close of 
last year was 198. Since that time 3 members have died : Mr. 
George Bancroft died January 17; Hon. Asa Owen Aldis, June 
24, and Professor William Ferrel, September 18, 1891. 
During the year 10 new members have been added to the list. 
The roll of new members is as follows: 
Thomas W. Smillie. Henry Newlin Stokes. 
Joseph Kay McCammon. Rollin Arthur Harris. 
William K. Carr. Albert L. Gihon. 
Isaac Winston. Mark W. Harrington. 
John Nelson James. G. L. Morton. 
