408 
MR, LOUIS VESSOT KING ON THE SCATTERING AND 
Table VI .—Belafire Intensities from Zenith Sky Calculated from Mount JFilson Ohservatimis in Terms of Mean 
A ttenuation Coefficients. 
The wave-lengths at Mount Wilson level corresponding to the tabulated values of the attenuation 
coefficients C were determined from the formula (76), C = + making use of the constants fi and y 
given in Table IT, which themselves are derived from observations on the transmission of solar-radiation. 
A large scale chart of the intensities in the normal solar spectrum outside the atmosphere was prepared 
from the data reproduced in Table I. The values of S corresponding to various values of A were then 
estimated from this curve of solar intensities. Auxiliary tables of the coefficients € 2 , e, ei were calculated 
from (44), making use of Table V. In this way a table of the function 
was prepared. This table, with Table III., enabled the term in scpiare brackets in the expression for 
T (0, {■) to be calculated. Finally, making use of the values of S just determined, the present table of the 
intensity from zenith sky, T (0, (), was calculated. The extreme and mean solutions of the integral 
equation are retained throughout. It will be noticed that the extreme solutions diverge rapidly for large 
values of C and f; it must be remembered that for large values of C the value of S decreases with extreme 
rapidity, no appreciable intensity having been measured for a wave-length less than • 3/x. Consequently, in 
calcrdating the total intensity of sky radiation on a horizontal surface, the divergence of the extreme 
solutions does not lead to a very great divergence in the final results. The results given in the present 
table are shown graphically in Diagrams II.-VII. 
