TABLE OF CONTENTS. IX 



117. . Miscellaneous data as to .the earth and planets . . . . . . . . . 106 



118. Aerodynamics : Data for wind pressure and values of J*"m P a = f a P^ 108 

 iig. " Data for the soaring of planes 109 



120. Terrestrial magnetism, total intensity no 



121. " secular variation of total intensity no 



122. " " dip in 



123. " " secular variation of dip in 



124. " " horizontal intensity .... 112 



125. " " secular variation of horizontal intensity . . .112 



126. " " formulae for value and secular variation of dec- 



lination 113 



127.. " " secular variation of declination (eastern stations) 114 



128. " " " " " " (central stations) 115 



129. . " " " " " " (western stations) 116 



130. " " position of agonic line in 1800, 1850, 1875, 



and 1890 117 



131. " " date of maximum east declination at various 



stations 118 



132. Tables for computing pressure of mercury and of water, British and 



metric measures 119 



133. Reduction of barometric height to standard temperature ..... 120 



134. Correction of barometer to standard gravity, British and metric mea- 



sures 121 



135. Reduction of barometer to latitude 45, British scale 122 



136. " " " " " " metric scale 123 



137. Correction of barometer for capillarity, metric and British measures . 124 



138. Absorption of gases by liquids 125 



139. Vapor pressures 126 



140. Capillarity and surface tension, water and alcohol in air 128 



141. miscellaneous liquids in air . . . .128 



142. " aqueous solutions of salts 128 



143. " " liquids in contact with air, water, or 



mercury 129 



144. liquids at solidifying point 129 



145. " " " thickness of soap films . . . . . .129 



146. Colors of thin plates, Newton's Rings 130 



147. Contraction produced by solution of salts 131 



148. " " " dilution of solutions 134 



149. Coefficients of friction 135 



150. Specific viscosity of water at different temperatures 136 



151. Coefficients of viscosity for solutions of alcohol in water 137 



152. Specific viscosity of mineral oils 137 



153. " " " various " 137 



154. " " " various liquids 138 



155. " temperature variation 139 



156. " " " solutions, variation with density and temperature . 140 



157. " " " " atomic concentrations 144 



