X TABLE OF CONTENTS. 



158. Specific viscosity of gases and vapors 145 



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



160. Diffusion 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 f$o 



165. Pressure of aqueous vapor (Regnault) 13,1 



1 66. " " " " (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 r<j6 



170. Hygrometry, vapor pressure in the atmosphere 157 



171. clew-points 158 



172. Values of 0.378^ in atmospheric pressure equation h=B 0.378^ . .160 



173. Relative humidity 160 



174. Table for facilitating the calculation of ^760 r62 



175. Logarithms of 7^/760 for values of h between 80 and 800 162 



176. Values of 1-^.0036"}?: 



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



(/;) " " " / " 90 and +1-990 C. by tens 165 



(r) Logarithms for / " 49 and +399 C. by units 166 



(ti) " " " t " 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 170 



(b) Metric measure ifi 



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



180. Wave-lengths of the Fraunhofer lines ^,5 



181. Various determinations of the velocity of light 176 



182. Photometric standards 176 



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



184. The solar constant '77 



1-85. Index of refraction of glass : 



(a) Fraunhofer's determinations 178 



(b) Bailie's " '7< s 



(c) Hopkinson's " '7 s 



(d) Mascart's " 17^ 



(e) Langley's " *79 



(/) Vogel on effect of temperature 



Of) Muller 



1 86. Indices of refraction for various alums 180 



187. " " " " metals and metallic oxides : 



(a) Kundt's experiments 181 



(ft) Du Bois and Ruben's experiments 181 



(f) Drude's experiments 181 



