TABLE OF CONTENTS. V 



fluence of Ocean Currents on, 108. Moisture : Influence of Earth on Pre- 

 cipitation of Moisture, 64 ; Connection of Sun Spots and Rain, 79 ; Tem- 

 perature of Rain-water, 121; Hail-storms in Europe, 124; Rain-fall in 

 Panama, 101. Instruments. Rain-gauge: Self-recording, 101; Barometer: 

 Joules', 102 ; Self-recording, 117 ; Sensitive Variation, 119 ; Thermometer : 

 Negretti's New Deep-sea, 103 ; Symons' Experiments, 124 ; Anemometer, 

 104 ; Universal Meteorograph, 105. 



C. PHYSICS (xxxvii) 125 



General : Resistance of Glass Tubes to Rupture, 125 ; Molecular Changes 

 in Iron with Temperature, 166 ; Disaggregation of Tin by Concussion, 169; 

 Crystalline Structure Produced by Concussion, 170 ; Connection between 

 Cleavage and Heat in Crystals and Rocks, 197 ; Mathematical Laws of 

 Elasticity, 130 ; New Mode of Determining, 131 ; Effect of Galvanic Cur- 

 rent on Elasticity of a Wire, 167 ; Electro-torsion, 168 ; Elastic Reaction 

 by Torsion, 168 ; Phenomena of Liquid Films, 129 ; Plateau's Glycerine 

 Liquid, 137 ; Vibration of Liquid Surfaces, 159 ; Evaporation of Liquids, 

 169 ; Molecules of Ether, 169 ; Diffusion of Gases, 142 ; Relationship of 

 Heat, Electricity, and Molecular Forces, 125 ; Report of British Association 

 on Dynamical and Electrical Units, 125; the Horizontal Pendulum, 167; 

 the Flight of Birds, 176. 



Sound : Terquem's Tonometer, 130 ; Electric Diapason, 135 ; Organ-pipes, 

 132 ; Mode of Hearing in Man and Mammals, 192 ; Duration of Sonorous 

 Sensations, 196; Sonorous Vibrations, 179; Observations on Sound, by Gal- 

 ileo, 134 ; Mechanical Equivalent of Sound, 189 ; Optical Method of Study- 

 ing the Vibrations of Solid Bodies, 191 ; Air-pressure Required to Sound 

 Various Wind Instruments, 195 ; Reflection of Sound from Flame and Heat- 

 ed Gases, 179; Vibrations of Liquid Surfaces, 194; the Atmosphere as a 

 Vehicle of Sound, 181 ; Acoustic Transparency of Air, 78, 159; Refraction 

 of Sound by the Atmosphere, 132, 187 ; Impermeability of a Non-homo- 

 geneous Atmosphere to Sonorous Vibrations, 179 ; Effect of Fog on Sound, 

 158 ; Effect of Wind on Sound-waves, 185. 



Light (see also Astronomy for Spectroscopy) : Laws of Reflection of 

 Light, 141 ; Effect of Temperature on Apparatus for Observing Solar Spec- 

 trum, 14; Width of Spectrum Lines, 160; Absorption of Spectra at Low 

 Temperatures, 145 ; Variability of Spectra, 172 ; Diffraction Gratings, 140 ; 

 Solar Spots and Solar Refraction, 15 ; Sunset Tints and Arcs, 68 ; Optical 

 Properties of Thin Metallic Films, 175 ; Elliptic Polarization of Light, 137 ; 

 Polarization by Diffusion, 138; Polarization of Flames, 138; Galvanic Po- 

 larization in Liquids Free from Gas, 139; Normal Flame for Photometric 

 Purposes, 142 ; Luminous and Non-luminous Flames, 144 ; Improved Elec- 

 tric Light, 160 ; Light from Grinding Hard Stones, 162 ; Fluorescence of 

 Amber, 143 ; the Black Drop, 145. 



Heat : Effect of Temperature on Apparatus for Observing Solar Spots, 14 ; 

 Specific Heat of Gases, 145 ; Atomic Heat, 171 ; Mechanical Equivalent of 

 Heat, 146 ; Expansion of Ebonite by Heat, 163 ; Molecular Changes of Iron 

 with Temperature, 166; Connection between Direction of Cleavage and 

 Conductivity of Heat, in Crystals and Larnellated Rocks, 197; True Zero 

 of Centigrade Thermometer, 164. 



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