372 F. W. Very — Sky Radiation and Isothermal Layer. 



an especially absorbent layer) here coinciding to reinforce the 

 phenomenon.* 



If the curve of absolute temperature between the surface 

 and an altitude of 10 km. be extended by estimate so that it 

 becomes asymptotic to the axis of altitude at 100 km. for abso- 



FlG. l. 



iUV 



x-m. 













qO 

















1_ 













80 



Jr 















\\ 













70 



\ \ 















\ 



\ 











60 



V 



\ 















\ 



N* 









50 







\ 

















\ 







40 









\ 

















\ 





30 











y 



















90 











i) e 













\ 1 







10 









X 



^ 















*^ 



















^\4Z 



00' 



200 c 



300 s 



lute zero,f we get the curve af of fig. 1, and a similar extension 

 of the curve of observation (which is already known up to 30 

 km., or just past the maximum of the inverted layer) gives 



* For examples, see the temperature-inversions recorded by W. R. Blair in 

 the Bulletin of the Mount Weather Observatory, vol. iv, part 5. observations 

 of September 22d and 30th, 1911, pp. 379 and 383, also Chart No. xviii. 



f The outer layers of hydrogen and other light gases will extend this curve 

 to greater altitudes, but we have not enough information to warrant the 

 extension at present. 



