374 
EXTENSION OF THERMODYNAMIC COMPUTATIONS 
The remedy for these difficulties is being considered in a special 
research. 
The Thermodynamic Terms 
Table 82 and Fig. 75 give the relations of (Q x — QQ = 
(Wi — Wo) + (Ui — U 0 ). (Qi - Qo) begins at the surface 
without value because the external work and the inner energy 
are in equilibrium; it increases by a curve determining the 
amount of the lower absorption to a point between the eleva 
tions 26,000 and 27,000 meters, this being the level where 
2 (Qi ~ Qo) = {Ui - U 0 ) - (Wi - Wo), which defines the true 
isothermal level where there is no absorption of solar energy, 
in the same sense that there is no absorption at the top and at 
the bottom of the atmosphere. This gives three points on the 
line of total solar energy, 9,806 on the vanishing plane, about 
5,780 at 26,800 meters, and 0 at the surface. The (E x — E 0 ) 
line of total solar radiation energy on the several levels was 
drawn by connecting these three points. The area between the 
axis of ordinates and the (Q x — Q 0 ) curve represents the free 
heat of transmission, the area between the (Q x — Q 0 ) and the 
(Ei — Eo) curves that of absorption, while (Ei — E 0 ) = 
(Qi— Qo) + (A x — Ao), the total area. The data on the several 
levels are for 1,000-meter areas, except below 3,000 meters, 
where the vertical height is 500 meters. The sum of these 
areas from the surface to 50,000 meters apparently represents 
the true “solar constant” of radiation energy, with the constit 
uents of transmission and absorption. 
The (Qi — Qo) curve continues to increase in value upward, 
as (Wi — Wo) and (XJ\ — U 0 ) separate, till a maximum value 
for the free heat of transmission is reached at — 6963 on the 
38,000-meter level. It will be shown that the pyrheliometer 
receives an amount of heat at the surface such as results from 
a summation up to about this elevation, as if this were the 
general efficient source of radiation at about 1.92 calories. 
The (Qi — Qo) and (Ei — E 0 ) curves begin to diverge at 27,000 
meters, and very rapidly after passing 38,000 meters. (Q x — Qo) 
falls to a minimum at 48,000°, and rises immediately to its