TABLE OF CONTENTS. V 



Barometer, 108 ; Convenient Form of Mercurial Barometer, 108 ; Improve- 

 ment in Aneroids, 111 ; Hipp's Anemometer, 113 ; the Aneroid Barometer, 

 116 ; a New Form of HN^grometer, 118. 



C. PHYSICS (xlv) 135 



General : The Relation between Gravitation and Energy, 135 ; Thomson's 

 Dead-beat Arrangement for Chemical Balances, 135 ; Simple Dynamome- 

 ter, 135 ; on the Elasticity of Rock-salt, 136 ; " Flow " of Metals, 137 ; Plas- 

 ticity of Ice, 137 ; Plastico-Dynamics, 138 ; an Experiment in Instantane- 

 ous Crystallization, 138 ; Frictional Resistance of Water to Motion of Ves- 

 sels, 139 ; the Movements of Waves and Vessels at Sea, 140 ; Vibration of 

 Fluid Columns, 140 ; on the Theory of the Flow of Water or Gas, 141 ; Hy- 

 draulic Investigations in India, 141; Gauss' Theory of Capillarity, 142; 

 Lippmann's Experiments on Capillary Attraction and his Electro-capillary 

 Motor, 142 ; on the Elasticity of Gases, 143 ; the Elasticity of Purified Air, 

 143 ; Air Pushed in Front of a Projectile, 144 ; on the Propulsion of Air by 

 a Jet of Air or Vapor, 144 ; Surface Tension of Liquids, 173 ; Metallic Fil- 

 tration, 174 ; Resistance of the Electric Arc, 175 ; Amalgamation of Iron, 

 177. 



Sound : Extending the Compass and Increasing the Tone of Stringed 

 Instruments, 145 ; Musical Sand, 179 ; Cause of Sound in Organ-pipes, 179 ; 

 Obliteration of One Sound by Another, 181. 



Light: The Mathematical Theory of Light, 151; Deep-sea Sound- 

 ing by Photography, 151 ; Dispersion of Light by Prisms, 152 ; Spec- 

 trum Dispersion of Gases, 153; Improved Spectroscopes, 153; Spectrum 

 Apparatus at Potsdam, 154 ; Atmospheric Lines of the Solar Spectrum, 

 154 ; Spectra of the Gases contained in Meteorites, 28 ; Spectrum of Cog- 

 gia's Comet, 57 ; the Coronal-line 1474 h, 44 ; Spectrum Observations of 

 the Stars, 48 ; the Spectroscopic Observatory at Calcutta, 40 ; Celestial Pho- 

 tometry, 7 ; on the Theory of the Aberration of Light, 8 ; Optical Notes 

 by Mr. Lea, 155 ; Method of Estimating Color in Water, 156 ; Fluorescence 

 of Solutions in Castor-oil, 150 ; Theories of Magnetism and Light, 157 ; 

 Action of Light on Ebonite, 176; the Dietheroscope, 187; Improved Mode 

 of Mounting Microscopic Objects, 188 ; the Gramme Light in Railroad De- 

 pots, 190. 



Heat : Conduction of Heat by Building Materials, 145 ; Change of Text- 

 ure in Sandstone by Heat, 140 ; Antiquity of the Burning Mirror, 146 ; Ob- 

 servations upon Radiometers, 146 ; Observations on the Theory of Crooke's- 

 Radiometers, 146 ; the Mechanical Production of Cold, 147 ; a New Ice Cal- 

 orimeter, 148 ; Experiments upon Non-luminous Flames, 149 ; Influence of 

 Pressure on Combustion, 150 ; the Absorption of Solar Heat by the Atmos- 

 phere, 150 ; New Metallic Pyrometer, 182 ; Conduction of Heat in Gases, 

 183 ; Cremation in France, 185. 



Electricity and Magnetism : Theories of Magnetism and Light, 157 ; 

 the Influence of Armatures upon INIagnets, 158 ; Formation of Natural INIag- 

 nets, 158; the Distribution of Magnetism in a IMagnet, 159; on the Distri- 

 bution of Magnetism in short thick Magnets, 159 ; on Magnets composed 

 of Compressed Powder, 100 ; on the Distribution of Magnetism in Bundles 

 of infinitely long, very thin Plates of Iron, 161 ; IMagnetic Observations in 



