516 



TABLE 531.— SOME ARTIFICIAL OPTICAL CRYSTALS (concluded) 



Part 2 



Index of refraction 



Material X 1st sample 2d sample 



KBr 486m 1.57181 1.57194 



.589 1.55986 1.55997 



.656 1.55503 1.55524 



to infrared (1-10m) 1.54 to 1.53 



KI 'uf md n D 



1.68755 1.6670 1.6588 



to infrared (1-20/0 1.64, 1.62 



LiF 4861 1.394810 ± 2 X 10" 6 



.5893 1.392057 



.6563 1.390862 



Thallium bromide-iodide (KRS-5)**. . . . Na 3 , 2.629; 1m, 2.45; 4/x, 2.4; 



10m, 2.39 ; 35m, 2.30 



Reference 

 C, b, e 



d,h 



b,g 



TABLE 532.— „ D , DISPERSION AND DENSITY OF JENA GLASSES 



No. and type of Jena glass n D * or " 



O 225 Light phosphate crown. . . 1.5159 



O 802 Borosilicate crown 1.4967 



UV 3109 Ultraviolet crown .... 1.5035 



O 227 Barium-silicate crown . . . 1.5399 



114 Soft silicate crown 1.5151 



O 608 High-dispersion crown .. 1.5149 



UV 3248 Ultraviolet flint 1.5332 



O 381 High-dispersion crown .. 1.5262 



O 602 Baryt light flint 1.5676 



S 389 Borate flint 1.5686 



O 726 Extra light flint 1.5398 



O 154 Ordinary light flint 1.5710 



184 " " " 1.5900 



748 Baryt flint 1.6235 



O 102 Heavy flint 1.6489 



O 41 " " 1.7174 



165 " " 1.7541 



S 386 Heavy flint 1.9170 



S 57 Heaviest flint 1.9626 



SMITHSONIAN PHYSICAL TABLES 



