CONTENTS. 



XV 



Standards: International secondary Fe arc standards, Angstroms . . 266 



'* International secondary Fe arc standards, Angstroms . , 266 



" Neon wave-lengths 266 



" International tertiary Fe arc standards. Angstroms ... 267 



Reduction of wave-lengths in air to standard conditions: 268 



(a) (d - do) /do X 1000; B, 60 to 78 cm, /, 9° to 35° C .... 268 



(b) 8 = \o(.no- no'){d- do)/do 268 



Spectra of the elements 269 



Spectrum lines of the elements (Kayser) 270 



Standard solar wave-lengths (Rowland) 272 



Spectrum series, general discussion 275 



" " limits of some of the series 276 



" " first terms and vibration differences 276 



Indices of Refraction 



Indices of refraction of glass (American) 277 



Dispersion of glasses of Table 325 277 



Indices of refraction of glasses made by Schott and Gen, Jena. ... 278 



Dispersion of Jena glasses 278 



Changes of indices for 1° C change for some Jena glasses 278 



Index of refraction of rock-salt in air 279 



Change of indices for 1° C change for rock-salt 279 



Index of refraction of silvine (potassium chloride) in air 279 



" " " " fluorite in air 280 



Change of indices for 1° C change for fluorite 280 



Index of refraction of Iceland spar (CaCOs) in air 280 



" " " nitroso-dimethyl-aniline 280 



'' quartz (SiOa) 281 



Indices of refraction for various alums 281 



" refraction: Selected isotropic minerals 282 



" " Miscellaneous isotropic soHds . 283 



" " Selected uniaxial minerals (positive) 284 



" (negative) ; . . . . 284 



" " Miscellaneous uniaxial crystals . 285 



" " Selected biaxial minerals (a) positive 286 



" (6) negative .... 287 



" " Miscellaneous biaxial crystals 289 



" " Liquefied gases, oils, fats, waxes 289 



" " Liquids relative to air 290 



" " Solutions of salts and acids relative to air . " . 291 



" " Gases and vapors 292 



" " Air, 15° C, 76 cm; also corrections for reduc- 

 ing wave-lengths and frequencies in air to vacuo (see Table 318) . 293 

 Media for microscopic determinations of refractive indices: liquids 



with nnio-SSgiJi) = 1.74 to 1.87 294 



