PROCEEDINGS. 
423 
plains various peculiarities in the spectra of gases. [Published 
in different form in Bureau of Standards Bulletin, vol. i, p. 83 
(1904).] 
The paper was discussed by Messrs. Briggs and Abbot. 
Mr. C. G. Abbot presented Recent studies on the solar constant 
of radiation made at the Smithsonian Astrophysical Observatory. 
The transparency of the air appears to vary greatly, the means 
for the first eight months of 1903 falling below the means for 
1901-2 by 5% in the infra-red, and up to 20% in the blue; in 
later months it has risen again. Prom the position of maximum 
radiation, outside the atmosphere (0.49 p), by Wien’s law the 
solar temperature is computed as 5800°-5900°. 
Mr. Day calculates from Abbot’s solar constant (2.167 calories 
per sq. cm. per min.) by Stefan’s law a temperature of 5750°. 
[Published in Smithsonian Miss. Col., vol. xlv, p. 74, Ko. 1421 
(1903).] 
579th Meeting. January 30, 1904. 
President Marvin in the chair. 
Twenty-six persons present. 
Mr. E. B. Rosa described at length The organization and work 
of the Bureau of Standards, detailing the problems before the 12 
divisions that deal with physical and engineering measures; the 
standards for thermometiy, photometrjq and electrical measure¬ 
ment were fully described. The chemical work has not yet been 
organized. [Published in Science, June 24, 1904.] 
Mr. L. J. Briggs then reported, with lantern illustrations, 
some of his work on The thickness of adsorbed aqueous films on 
powdered quartz. This was found to be about 6 pp, a quantity 
insignificant with respect to the thickness of the outer wall of a 
root fiber, which is 600 pp. [Published in Journal of Physical 
Chemistry, vol. ix, p. 617 (1905).] 
Messrs. King and Guthe discussed the paper. 
