SOLAR AND TERRESTRIAL RADIATION 
377 
is commonly used in the pressure P 10 . The reduction from 
mechanical units to heat units (C. G. S.) is by the factor 
4 1851 X HF anC * t ^ ie ^ actor ^ or c ^ an ge from second to minute 
is 60. Hence, to reduce (Qi — Q 0 ) in 
. gram calorie . . 
into —r ;——, the factor is, 
cm. 2 minute 
M. K. S., mechanical units 
10000 X 60 
1000 X 4.1851 X 10 7 
6X10~ 5 
4.1851 
= 0.000014336; Log.-5.15644. 
Compare the constants, coefficients, and dimensions of Table 95, 
where the formulas afford many other combinations in conform 
ity with the kinetic theory of gases. 
The Total, Transmitted and Absorbed Amounts of the Solar and 
the Terrestrial Radiations 
Huron, September i, içio 
The method of separating the total radiation {Ei — Eo) 
received at the earth from the sun into the transmitted (Qi — Q 0 ) 
and the absorbed (Ai — A 0 ) constituents on each level has been 
explained. The coefficient of transmission is p = vr 
Ei — Eo 
j ^ 
and of absorption is k = v,-—-=r. The terrestrial radiation 
Ei — Eo 
is obtained as follows : Let J 0 = c T 4 , the black body radiation 
of the atmosphere at the point whose temperature is T; let 
J a = cT a the actual radiation for c and a as computed from 
the thermodynamic data, so that the actual absorption between 
two planes is J a . x — J a .o = Ci Tf l — c 0 T 0 a °. The general 
equation of radiation equilibrium is 
2 J 0 = E + D, where D is the total terrestrial radiation. 
Hence, D = 2 J 0 — E, and B = D — J a , where B is the trans 
mitted terrestrial radiation. The coefficient of terrestrial 
transmission is p 1 = 
Bi — Bp 
Di - Do’ 
and that of absorption is k 1 = 
j q.1 Ja-0 
A - Do' 
The results of these computations appear on Table