MISCELLANEOUS TABLES. lxXl 



humidity obtained from Table 99. The logarithms are given to five signi- 

 ficant figures and the corresponding numbers to four decimal places. 



Table 1 01 . Atmospheric water-vapor lines in the visible spectrum, table 101. 



Table 101, prepared by the Astrophysical Observatory at Washington, 

 gives a summary of lines in Rowland's "Preliminary Table of Solar Spec- 

 trum Wave Lengths," recorded as of atmospheric water vapor origin. There 

 are more than 400 such lines in Rowland's table, but an abridgment is here 

 made as follows: 



Only lines of intensity " 1 " or greaterare here separately given, but the 

 total number and average intensity of the fainter lines lying between these 

 are inserted. Rowland's scale of intensities is such that a line of intensity 

 "1" is "just clearly visible" on Rowland's map; the H and K lines are 

 of intensity, 1,000; D z (the sodium line of greater wave length), 20; C, 40. 

 "Lines more and more difficult to see" are distinguished by o, 00, 000, 

 and 0000. TnDir 



TABLE 102. 



Table 102. Atmospheric water-vapor bands in the infra-red spectrum. 



The values of Table 102 relate to the transmission of energy in the minima 

 of various water-vapor bands, when there is 1 cm. of precipitable water in 

 the path through the air. For other amounts of water-vapor, the depths of 

 these minima may be taken as equal to a s , where a is the coefficient taken 

 from the third column of Table 102 and 5 is the amount of precipitable 

 water in the path. For average conditions in the transmission of radiation 

 through the atmosphere, 5 may be determined by the modification of 

 Hann's formula 0* = 2.0 e sec. Z, where e is the vapor pressure in cms. as 

 determined by wet and dry thermometers and Z is the angle which the 

 path makes with the vertical. 



For the use of the transmissions observed in such bands for the inverse 

 process of determining the amount of water-vapor in the atmosphere, see 

 Fowle, Astrophysical Journal, 35, p. 149, 1912; 37, p. 359, 1913. 



TABLE 103. 



Table 1 03. Transmission percentages of radiation through moist air. 



The values of Table 103 will be of use when the transmission of energy 

 through the atmosphere containing a known amount of water-vapor is 

 under consideration. An approximate value for the energy transmitted 

 may be had if the amount of energy from the source between the wave- 

 lengths of the first column is known and is multiplied by the corresponding 

 transmission coefficients of the subsequent columns of the table. The table 

 is compiled from Fowle, " Water- vapor Transparency," Smith son tan Mis- 

 cellaneous Collections, 68, No. 8, 1917; see also, Fowle, "The Transparency 

 of Aqueous Vapor," Astrophysical Journal, 42, p. 394, 1915. 



Table 104. International meteorological symbols. table 104. 



The information under this heading has been compiled for the present 



