38 



SMITHSONIAN MISCELLANKOUS COLLECTIONS 



VOL. 



Preliminary Observations 

 Meteorological 



The sky conditions were seldom constant for any great length of 

 time on Flint Island, so that pyrheliometer readings were not often 

 attempted. On December 29, at noon, the intensity of solar radiation 

 at the camp was 1.423 calories per square centimeter per minute, with 

 fine blue sky. 



Mr. Moore observed on Flint Island the temperatures of wet and 

 dry bulb thermometers, barometric pressure, direction, and approxi- 

 mate velocity of the wind in miles per hour, and cloudiness, at the 

 hours 7 a. m., 11^ 18™ a. m., 5 p- m., and 9 p. m., each day from 

 December 10, 1907, to January 4, 1908. Without giving individual 

 values, excepting for January 3, a summary of the mean results of 

 his observations follows. The column marked P indicates the press- 

 ure of aqueous vapor at the earth's surface in centimeters of mer- 

 cury, and that marked Q the corresponding total precipitable water in 

 a vertical column of the atmosphere 1 sq. cm. in cross-section, ac- 

 cording to Hann's formulae. 



BOLOMETlilC 



The eclipse observations are of much more interest when consid- 

 ered along with other observations which have been made of the 

 relative brightness and quality of sun, sky, and moon rays. 



Sun-brightness, Sky-brightness, and Moon-brightness ' 

 On December 29, 1907, one of the very few days during our stay 

 on Flint Island when the sky was mostly free from clouds and of a 



* I propose to employ these terms for brevity, to mean the intensity of the 

 radiation of the sun, sky, or moon transmissible by glass, and therefore of 

 less wave-length than 3 ^. 



