X TABLE OF CONTENTS. 



158. Specific viscosity of gases and vapors 145 



159. " " " " formulae for temperature variation . . . .146 



160. Ditlusion of liquids and solutions of salts into water 147 



161. " " vapors 148 



162. " " gases and vapors 149 



163. Isotonic coefficients and lowering of the freezing-point 150 



164. Osmotic pressure 150 



165. Pressure of aqueous vapor (Regnault) 151 



166. " " " " (Regnault and Broch) 154 



167. Weight in grains of aqueous vapor in a cubic foot of saturated air . . 155 



168. " " grammes of " " " " metre of " " . . 155 



169. Pressure of aqueous vapor at low temperatures 156 



170. Hygrometry, vapor pressure in the atmosphere 157 



171. " dew-points 158 



172. Values of o.378t' in atmospheric pressure equation h-=^B — 0.378^ . . 160 



173. Relative humidity 160 



174. Table for facilitating the calculation of ///760 162 



175. Logarithms of ///760 for values of h between 80 and 800 162 



176. Values of i -j-. 00367/.- 



(a) For values of / between 0° and 10° C. by tenths 164 



\b) " " " / " —90° and 4-1990° C. by tens 165 



(c) Logarithms for / " —49° and +399° C. by units 166 



(d) " " " / " 400^ and 1990° C. by tens 168 



177. Determination of heights by barometer 169 



178. Barometric pressures corresponding to different temperatures of the 



boiling-point of water : 



(a) British measure 17° 



(l>) Metric measure 17^ 



179. Rowland's standard wave-lengths in arc and sun spectra 172 



180. Wave-lengths of the Fraunhofer lines 175 



181. Various determinations of the velocity of light 176 



182. Photometric standards i?^ 



183. Solar energy and its absorption by the terrestrial atmosphere .... 177 



184. The solar constant ^77 



185. Index of refraction of glass : 



(a) Fraunhofer's determinations 178 



(d) Bailie's " 178 



(c) Hopkinson's " 178 



(d) Mascart's " ^79 



(e) Langley's " ^79 



(/) Vogel on effect of temperature ^79 



(j^) Miiller " " " " 179 



186. Indices of refraction for various alums 180 



187. " " " " metals and metallic oxides : 



(a) Kundt's experiments 181 



(li) Du Bois and Ruben's experiments 181 



(/) Drude's experiments 181 





