PROCEEDINGS. 
411 
our Society had a share—Messrs. Mendenhall and Paul. A 
large instrument was exhibited of the “inertia type/’ in which a 
large suspended mass serves as a fixed point for attachment of a 
system of levers the distant end of which carries a recording 
point, while a frame subject to the earth tremors engages the 
levers at an intermediate point. [Published in Monthly Weather 
Keview, June, 1903.] 
Mr. Newcomb described briefly the instruments shown him 
at Gottingen, and further remarks on the subject were made by 
Messrs. Gilbert and Abbe. 
'Mr. A. L. Day then, with the aid of lantern-illustrations, 
presented the modern view of Black bodies, and the great devel¬ 
opments that followed the introduction of the hollow internally 
reflecting and radiating shell whose radiations reached an outside 
instrument through a small hole, instead of the older imper¬ 
fectly radiating bodies. It is found that as the temperature of 
such a shell rises, not only the total energy of radiation increases 
rapidly, but the wave length of the maximum radiation: so two 
methods of computing the temperature from the radiations have 
been developed. [Not published.] 
Some points of the paper were discussed by Messrs. Bigelow 
and Wead. 
565th Meeting. March 14, 1903. 
Vice-President Marvin in the chair. 
Forty-two persons were present. 
Announcement was made of the death of Mr. Wm. Harkness 
on February 28th. 
Mr. Abbe exhibited a recent publication of the Weather 
Bureau, containing half-tone plates of hundreds of Microphoto¬ 
graphs of snow-crystals made by Mr. Bentley, of Jericho, Vt. 
President Gore, having taken the chair, stated that Mr. G. T. 
Walker, of India, in his demonstrations of the Flight of boom¬ 
erangs, this afternoon on the White Lot, had suffered a severe 
strain and w^as unable to appear and present his discussion of the 
instrument, which had been announced. An informal discus- 
