Bigelow — Determination of the " Solar Constant" 281 



The effective radiation, I=A — J a — B, is built up of the 

 total solar radiation A =4*00, neutralized in the lower levels 

 by the emitting radiation J a from 1*46 to the vanishing quan- 

 tity at about 40,000 meters, and the return radiation B = I on 

 every plane during steady temperatures. The pyrheliometer 

 at any station observes the "effective" radiation I, and never 

 the solar constant, which is A=2I on the upper level where 

 J a =0. The depth of m in the Bouguer Formula is about 

 3000 meters for each constant p in the lower levels. The 

 value of^> changes from £>=0*83 at sea level, through ^=0*86, 

 ^=0*89, 2? = 0*92 .... £> = 1*00 in the upper levels, so that, 



(8) l=z\p™i.p™*. p™* p Q m *. 



The total solar constant A =4*00 is neutralized by J a and by 

 the return radiation B which is continuous, otherwise the 

 temperatures would change in values. At night I = B = A=0, 

 and the nocturnal radiation proceeds from J a only. 



If the spectrum energy of a 6900° black body radiation is 

 computed, and the ordinates summed for A X = 0*05/<c, the 

 sum is 80*30; if the Abbot observed ordinates are summed for 

 Washington, D. C, the result is 51*19; for Mt. Wilson 

 (1780 m.) it is 59*55; for Mt. Whitney (4420 m.) it is 61*38; for 

 the topmost curve (8000 m.) it is 67*26. Hence by division 

 the ratios for the absorbed parts of the spectrum are readily 

 found. Similarly, divide the values of J a by A on the same 

 levels, and we obtain the ratio of absorption. 



Station 



Bolometer spectrum 

 Thermodynamics ._ ._ 0*362 



Washington 

 34 m. 



Mt. Wilson 

 1780 m. 



Mt. Whitney 

 4420 m. 



Assumed 

 8000 m. 



_ 0*363 



0*258 



0*236 



0*162 



_ 0*362 



0*287 



0*225 



0*163 



This shows that the energy lost in bolometer spectrum is 

 the same as J a , and it is absorbed in the lower levels. 



Oficina Meteorologica, Buenos Aires, Argentina. 

 March, 1914. 



