380 Tables 426-428 



TABLE 426. — Percentage Refleotion from Metals, Violet End of Spectrum 



(Coblentz, Stair, Bur. Standards Journ. Res., 2, 343, 1929.) 



Wave length in /j. 05 .10 .15 .20 .25 .30 .35 



Ni electroplated 40 44 51 



" vac. fused 



Ag (min. 7%, 33^) 



Stellite (Co, Cr, Mo) 



Stainless steel, 13% Cr 



Cobalt 



Speculum 



Beryllium (987%) 46 53 67 79 



Chromium on steel 69 63 65 71 



30 

 46 

 40 

 43 

 31 

 84 

 78 



42 

 16 

 49 

 47 

 46 



41 



87 

 82 



45 

 71 



55 

 52 

 52 

 50 



.40 

 53 

 52 

 88 

 60 

 56 

 58 

 56 



•50 

 56 

 62 

 92 

 64 

 59 

 62 

 60 



.60 

 (60) 

 64 

 (94) 

 (68) 

 (60) 

 (67) 

 (62) 



TABLE 427.— Ultra-violet Reflecting Power of Some Metals 

 (Coblentz, Stair, Bur. Standards Journ. Res., 4, 189, 1930.) 



0.250/j, .300 

 Aluminum, cast, polished. .43 



rolled 21 



Rhodium 30 



Tin, polished 33 



Duralumin 24 



tarnished to .20 



TABLE 428. — Infra-red Reflectivity of Tungsten (Temperature Variation) 



Three tungsten mirrors were used, — a polished Coolidge X-ray target and two polished flattened wires mounted 

 in evacuated soft-glass bulbs with terminals for heating electrically. Weniger and Pfund, J. Franklin Inst. 



See also Weniger and Pfund, Phys. Rev. 15, p- 427i IO -i9- 



Smithsonian Tables. 



