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MR. LOUIS VESSOT KING ON THE SCATTERING AND 
Table VIII. —Eelative Intensities from Zenith Sky Calculated from JVashington Observations in Terms of 
Mean Attenuation Coefficients. 
This table is constructed on the same plan as Table VI. for Mount Wilson, making use of the attenuation 
constants given in Table II. for Washington. The effect of “ dust ” recjuires us to make use of different 
constants for long- and for short-wave radiation in calculating wave-lengths corresponding to the tabulated 
values of C from the formula C = -|- y. The result is a discontinuity in the sky radiation curve in 
the neighbourhood of -GlO/r, shown in the curves of Diagram XII. The mean value of the solution of 
the integral equation is alone given, since the values of the absorption coefficients vary so rapidly from 
day to day that the intensities of sky radiation calculated from them probably differ by more than the 
difference bet\reen the extreme solutions, 
