416 
MR. LOUIS VESSOT KINO ON THE SCATTERING AND 
Table X .—Quality of Sky Puidiation at Mount JFilson, October 17, 1906. 
Observations on the quality of sky-radiation have been made at Mount Wilson.* The values given in 
the present table are calculated in terms of the mean coefficients of attenuation at that station. The units 
of intensity in the calculated and observed values are both arbitrary. The calculated intensities are 
reduced to the same units as the observed intensities by multiplying the former by the mean value of the 
ratios of the intensities corresponding to the different wave-lengths. The results are compared graphically 
in Diagram XIII. The agreement is seen to be fairly satisfactory, in spite of the fact that the mean va\nes 
of the coefficients of attenuation are used in calcidating intensities on a particular day. 
* ‘Annals,’ vol. II., ji. 155. 
