CONTENTS. 



173- 

 174. 



175- 

 176. 



177. 

 178. 

 179. 

 180. 

 181. 

 182. 



183. 



184. 



185. 



186. 



187. 



188. 

 189. 



190. 



191. 



192. 



193- 

 194. 



195- 

 196. 



197. 

 198. 



199. 



200. 

 201. 



202. 



203. 



204. 



205. 



206. 



207. 



208. 



209. 



210. 

 211. 

 212. 

 213. 

 214. 

 215. 



The solar constant and temperature .... 

 Solar spectrum energy ; atmospheric transparency 

 Distribution of solar energy in spectrum 

 Distribution of intensity of radiation over solar disk . 

 Transmissibility of radiation by dry and moist air 



Brightness of sk^ 



Relative intensmes of sun- and sky-light 



Air masses ....••••• 



Relative intensities of solar radiation — monthly change 



Mean monthly and yearly temperatures 



Indices of refraction of Jena glasses .... 



" ** " u « u .... 



'« " '< « a " temperature coefficients 



" " *' for rock salt .... 



" « " " " " temperature coefficients 



" " " " sylvine 



'« " " " fluorite 



" «' « " " temperature coefficients 



" " " " Iceland spar 



" " " " nitroso-dimethyl-aniline 



" " " " quartz 



" " " " various alums 



" " " " " monorefringents 



" •' " " " uniaxial crystals 



<' " " *' " biaxial crystals 



" '* " " solutions of salts and acids : 



(a) solutions in water 

 (I?) " " alcohol . 



(r) " " potassium permanganate 



*' " " " various liquids 



" •' ** " gases and vapors . 



Standard refractive media : n = 1.74 to 1.87 

 " " '' n= 1.68 to 210 



" " " «= 1.546 to 1.682 . 



Optical constants of metals — (definitions) 



Reflecting power of metals 



Reflection of light, perpendicular incidence : various values 

 " " " incidence varying : n near unity 

 " " " " " « = i.55 . 



Reflection from metals 



" " various materials .... 



Transmissibility of radiation by Jena glasses 



«« " " " " ultra-violet glasses 



of n 



