538 
PHILOSOPHICAL SOCIETY OF WASHINGTON. 
lished in the National Geographic Magazine. 8°, Washington, 
1894, Dec. 29, vol. 6, pp. 229-238.] 
Remarks were made by Mr. G. Brown Goode. 
Mr. C. K. Wead made a communication on A possible ex¬ 
planation of the periodic inversion of Bigelow’s curve. [Not 
published.] 
This was discussed by Messrs. Bigelow and Mendenhall. 
Mr. H. A. Hazen made a communication on Auroras and sun 
spots. [Published in the American Meteorological Journal. 8°, 
Boston, 1894, Oct., vol. 11, no. 6, pp. 221-228.] 
Remarks were made by Mr. Bigelow. 
424th Meeting. October 27, 1894. 
President Fletcher in the chair. 
Twenty-five members and guests present. 
Announcement was made of the death of the following mem¬ 
bers of the Society: 
James Clarke Welling, on September 4, 1894. 
Robert Stanton Avery, on September 12, 1894. 
Garrick Mallery, on October 24, 1894. 
Mr. Victor L. Mason read, by invitation, a paper on Modern 
munitions and engines of war in the United States military 
service. It was illustrated by photographs loaned by the Bureau 
of Ordnance of the War Department. [Published in the Cen¬ 
tury Magazine. 8°, New York, 1895, Feb., vol. 49, no. 4, pp, 
570-583.] 
Remarks were made by Messrs. Ward, Harkness, Dall, 
Chatard, Baker, Weed, and the President. 
425th Meeting. November 10, 1894. 
President Fletcher in the chair. 
Forty members and guests present. 
Mr. S. P. Langley presented a communication on Bolography 
of the infra-red spectrum; it was illustrated by photographs 
