NO. 8 



WATER- VAPOR TRANSPARENCY FOWLE 



43 



F. Atmospheric Absorption of Solar Energy. 9 to 15 /x. 



G. Collected Results on Atmospheric Absorption for Long-wave 

 Radiation. 



H. Subsidiary Investigations. 



( 1 ) Corrections for slit and bolometer widths. 



(2) Field energy due to scattering. 



(3) Transparency of iodine. 



(4) Comparison of Nernst-lamp spectrum with that of black-body. 

 It is proposed first in this summary to indicate the information 



available on the absorption in aqueous vapor, not only as obtained in 

 the present research, but also as selected from the work of others. 



Fig. 14. — Contour solar energy-curve, 60° ultra-violet glass prism. Region 

 of atmospheric absorption bands. 



A. ABSORPTION IN WATER VAPOR, WAVE-LENGTHS LESS THAN 2 fx. 

 (l) ATMOSPHERIC CONDITIONS 



The region from 0.6 ^ to 2.1 fx contains the absorption bands due 

 to atmospheric water vapor and oxygen which chiefly affect the 

 incoming energy from the sun. For wave-lengths less than 0.6 fi, 

 except for a slight absorption due to a large number of small lines 

 in the neighborhood of the D lines, the losses are due principally to 

 molecular scattering. These losses are fully described in the follow- 

 ing references : 



