Vlll CONTENTS. 



94. Terrestrial magnetism : secular change of horizontal intensity . -113 



95. " " total intensity 114 



96. " " secular change of total intensity . , .114 



97. " " agonic line . . . * ;, . 115 



98. Pressure of mercury and water columns . . . . .116 



99. Reduction of barometer to standard temperature . . . . . 117 



100. " " " " " gravity, inch and metric scales . 118 



101. " " " " latitude 45 : inch scale . . v .119 



102. " " " " " " metric scale . . ,. . 120 



103. Correction of barometer for capillarity : inch and metric scale . .121 



104. Aerodynamics: data for wind pressures . . . . .122 



105. " " " the soaring of planes 123 



1 06. Coefficients of friction . . . . . . . . . .124 



107. Viscosity of water at different temperatures . . . . . 125 



108. Coefficients of viscosity for solutions of alcohol in water . . .126 



109. Specific viscosity of mineral oils . . . . . .126 



no. " " " various oils > . 126 



in. " " " " liquids .127 



112. " " " " " temperature variation . --Y . 128 



113. " " solutions: variation with density and temperature. 129 



114. " " " " atomic concentrations .... 133 



115. " " " gases and vapors . . . . . . . 134 



116. " u " " " " temperature variation . . 135 



117. Diffusion of an aqueous solution into pure water 136 



118. " " vapors 7~ 137 



119. " gases and vapors ........ 138 



1190. " metals into metals ........ 138 



120. Solubility of inorganic salts in water: temperature variation . . 139 



121. " " a few organic salts in water : temperature variation . . 140 



122. " " gases in water . . 140 



123. Absorption of gases by liquids . . . . . . . .141 



124. Capillarity and surface tension : water and alcohol in air . .142 



125. " " " " miscellaneous liquids in air . . 142 



126. " aqueous solutions of salts . . .142 



127. Capillarity and surface tension : liquids in contact with air, water or 



mercury ........... 



128. Capillarity and surface tension : liquids at solidifying point . 



129. " " " " thickness of soap films 



130. Vapor pressures 



131. " " of ethyl alcohol . . . . 



132. " " " methyl " 



133. and temperatures : (a) carbon disulphide . 



(b) chlorobenzine 



(c) bromobenzine 



(d) aniline .... 

 (<?) methyl salicylate . 



(f) bromonaphthaline . 



(g) mercury 



