394 



Tables 456-458 

 FAR INFRA-RED, 20 TO 1 50 M 



(John Strong, Phys. Rev., 38, 1818, 1931.) 

 TABLE 456. — Restrahlung bands 



* The use of a paraffin window about 3 mm thick stops the short wave length restrahlung of quartz 

 at 8.7tt and of calcite at 6.711. 

 t Weak reflection at 41/1. 



TABLE 457. — Reflecting Power 



X — zo/l 25 33J 50 66§ 100 150/1 



~/cm = 500 400 300 200 150 100 66§ 



Rough brass 67 70 78 83 92 96 100 (1) 



24 33 42 58 68 81 99 (2) 



" " 12 14 17 21 25 40 82 (3) 



Galena 31 30 21 51 73 76 76 (4) 



Zincite 50 35 18 21 18 20 15 (5) 



(3 magnesia, fused 80 60 34 30 30 30 30 



Stibnite 21 20 4 39 48 52 39 (6) 



Sphalerite 10 15 29 20 19 18 17 (6) 



Corundum (30) 41 26 31 29 24 22 (6) 



Cuprite 45 47 47 42 41 42 46 



(1) Ground with No. 60 carborundum. (2) Ditto No. 220. (3) Ditto No. 400. (4) Surface 



to cleavage plane, highly polished. (5) Natural crystal. (6) Qualitative only. 



TABLE 458. — Transmission 



X = 20/t 



-/cm = 500 



KBr 



Kl 



Amorphous SiG\> 3 



CCh liquid (57) 



KCl 97 



(7) No corrections for reflections. (8) Evaporated on lacquer film. 



Smithsonian Tables 



