262 Bigelow — Radiation in the Earffis Atmosphere. 



Table 9. — Approximate values of a for summer temperatures. 



z 



90° 



80° 



70° 



60° 



50° 



40° 



30° 



20° 



10° 



0° 



19000 



3.76 



3-75 



3'75 



3-75 



3 '75 



3-75 



3-75 



3'75 



3-75 



3-75 



18000 



3-77 



3-76 



3-76 



3-76 



376 



3 76 



3-76 



3'76 



3-76 



3-76 



17000 



3-78 



3-78 



3-77 



3-77 



3-77 



3-77 



3-77 



3-77 



3'77 



3-77 



16000 



3'79 



3-79 



3'78 



3-78 



3-78 



3-78 



3-78 



3-78 



3-78 



3-78 



15000 



3-80 



3'80 



3'80 



3-79 



3'79 



379 



3-79 



3'79 



3-78 



379 



14000 



3-81 



3-81 



3-81 



3'80 



3-80 



3-80 



3-79 



3-79 



3-79 



3-79 



13000 



3'82 



3-82 



3' 82 



3'81 



3'81 



3-80 



3-80 



3-79 



3 79 



3-79 



12000 



3-83 



3'83 



3-82 



3-82 



3'82 



3-81 



3-80 



3-80 



3 80 



3-80 



11000 



3-83 



3-83 



3-83 



3'83 



3-82 



3-81 



3-80 



3-80 



3 80 



3-80 



10000 



3'84 



3-84 



3-83 



3-83 



3-82 



3-81 



3-80 



3-80 



3-80 



3-80 



9000 



3-84 



3-84 



3-84 



383 



3-83 



3-82 



3-81 



3-80 



3-80 



3-80 



8000 



3-84 



3-84 



3 84 



3-83 



3 83 



3-82 



3-81 



3-80 



3-80 



3-80 



7000 



3-85 



3 84 



3-84 



3-83 



383 



3-82 



3-81 



3-80 



3-80 



3-80 



6000 



3-85 



3 85 



3-84 



3-83 



3-83 



3-82 



3-81 



3-80 



3-80 



3-80 



5000 



3-85 



385 



3-84 



3-83 



3-83 



3-82 



3-81 



3-81 



3-81 



3-81 



4000 



3-85 



3-85 



3-85 



3-84 



333 



3-82 



3-81 



3-81 



3-81 



3-81 



3000 



3-86 



3-86 



3-85 



3-84 



3-83 



3-83 



3 82 



3-81 



3-81 



381 



2000 



3-86 



3-86 



385 



3-84 



3-84 



3-83 



382 



3-82 



3-82 



3-82 



1000 























000 























The corresponding values of log c can be taken from Table 3. 

 The italic types indicate the position of the isothermal region, 

 and in it the values of a fall to about 3*75 at 19,000 meters 

 whatever the value may be at a given latitude on entering this 

 peculiar stratum or whatever its value at the surface. The 

 rise in value from the equator to the pole is evident in all levels 

 below the isothermal region. These then are the fundamental 

 conditions to be considered in seeking a physical explanation 

 of the isothermal region. It may be remarked in passing that 

 these data afford no support for Abbot's hypothetical effective 

 radiation layer, depending upon the heating effect of the 

 aqueous vapor at about 4000 to 5000 meters elevation. Hum- 

 phreys in several papers has given some general arguments in 

 favor of the following hypothesis. Assume in the isothermal 

 layer, and in the lower effective radiating layer, 



Isothermal layer, . _ K 2 



Lower effective layer K 



whence, we have, T 1 



bK, = Cl T,"., 



( 4 f) 



1 a 



^T (i aT. (14) 



