Tables 459 and 460 



395 



REFLECTION AND ABSORPTION OF LONG-WAVE RADIATIONS 

 TABLE 459. — Long-wave Absorption by Gases 



Unless otherwise noted, gases were contained in a 20 cm long tube. Rubens, Wartenberg, Verh. d. Phys. Ges. 

 13, P- 796, 191 1. 



* Steam ioo° C passed through tube 40 cm long, 150 C; 0.06 cm ppt. H 2 0. 

 t Pentane vapor, pressure 36 cm. 



TABLE 460. — Properties with Wave-lengths 108 ± n 



Rubens and Woods, Verh. d. Phys. Ges. 13, p. 88, 1911. 

 With quartz, 1.7 cm thick: 60 to Sofj.. absorption very great; 63^, 99%; 82JJ, 97 



(a) Percentage Reflection. 



Alcohol 



* Restrahlung from KBr. 



t Isolated with quartz lens. 



(b) Percentage Transparency. 

 Uncorrected for reflections. 



Solid. 



Paraffin 



Mica 



Hard rubber. . . 

 Quartz || axis . 

 Quartz, amorph 



Rock salt 



Fluorite 



Diamond 



Quartz J_ axis . 



Thickness. 



3 °3 



0.055 



059 

 1 . 26 



2.00 



4 03 



7. 26 



11.74 



14.66 



Transparency, 



5-3 

 45-3 

 81.3 

 66.4 

 49-8 

 35-5 



Liquid. 



Benzene .... 

 Ethyl alcohol 

 Ethyl ether . 



Water 



Water 



Vapors: 



Alcohol. . . 



Ether 



Benzene . . 



Water 



CO2 



Thickness. 



0.158 

 0.158 

 0.029 



0.044 



Thickness 



precipi- 



table 



liquid. 



0.023 

 0.350 

 0.063 



Trans- 

 parency. 



56.8 

 7-9 

 37-1 

 25.8 

 13.6 



33-5 

 100 



19.6 

 100 



(f) Transparency of Black Absorbers. 



Method and wave-length. 



Spectrometer 



Fluorite " reststrahlen " 

 Rock salt " reststrahlen ' 

 Quartz lens isolation 



2/J 



4 

 6 



52 

 108 



Black silk 



paper, 



.025 mm thick 



0.9 



1.7 



8.2 



24. 2 



46.0 



61.5 



Opaque black 



paper, 

 0.11 mm thick 



Black card- 

 board, 

 0.4 mm thick. 



Candle lamp- 

 black, 

 10 cm 2 = 1.8 

 mg 



Smithsonian Tables. 

 15 



