3o8 



Table 377. 

 TRANSMISSION PERCENTAGES OF RADIATION THROUGH MOIST AIR. 



{For bodies at laboratory temperatures; for transmission of shorter-wave energy, see Table SS3-) 



The values of this table will be of use for finding the transmission of energy through air containing a known amount 

 of water vapor. An approximate value for the transmission may be had if the amount of energy from the source be- 

 tween the wave-lengths of the tirst column is multiplied by the corresponding transmission coefficients of the subse- 

 quent columns. The values for the wave-lengths greater than iS/x are tentative and doubtful. Fowle, Water-vapor 

 Transparency, Smithsonian Misc. Collections, 68, No. 8, 1917; Fowle, The Transparency of Aqueous Vapor, Astro- 

 physical J. 42, p. 394, 1915. 



The following table, due to Rubens and Aschkinass (Annalen d. Physik u. Chemie, 64, p. 598, 1898), gives the 

 absorption of radiation from a zircon burner by a layer 75 centimeters thick of water vapor saturated at 100° C. This 

 amount of vapor is about equivalent to a layer of water 0.4s millimeter thick or to i.s% of the water in a total vertical 

 atmospheric column whose dew point at sea-level is 10° C. The region of spectrum examined includes most of the 

 region of terrestrial radiation. 



Wave-length 7.0M 8.0/i 9.0-12.0/1 I2.4M i2.8jU I3.4M i4-0Ai 



Percentage absorption 75 40 6 20 13 28 22 



Wave-length 14. 3M iS-Oli IS-?/* 16.0M 17. SM 18.3/* so.cft 



Percentage absorption 43 3S 6$ S3 88 80 100 



Smithsonian Tables. 



