ivr TABLE OF CONTENTS. 



perature of the Earth. 119; Earth Temperature at Konigsberg, 120; Noc- 

 turnal Radiation, 72 ; Changes in the Earth's Axis of Rotation, 78 ; the In- 

 tensity of Twilight, 99 ; on the Quantity of Light Reflected by the Sky in 

 the Daytime, 99; the Interior Structure of the Earth, 121 ; Correlation of 

 Solar and Terrestrial Phenomena, 8 ; Change of Texture in Sandstone by 

 Heat, 146; the Absorption of Solar Heat by the Atmosphere, 150; Tem- 

 perature Observations in Itah^, 128 ; Connection between Solar Spots and 

 Terrestrial Electricity, 122 ; Magnetic Observations in the Indian Ocean, 

 162 ; Magnetic Map of France, 162 ; on the Deviation of the Compass, 162 ; 

 Influence of Forests on Water-flow and Atmospheric Moisture, 77. The 

 Interior Waters : The Temperature within the Great Geyser of Iceland, 

 109 ; River Currents as Affected by the Earth's Rotation, 119 ; the Thermal 

 Springs of the United States, 121 ; the Diminution of Water in Springs, 

 Rivers, and Wells, 131. The Ocean: Mechanical Theory of Ocean Cur- 

 rents, 65 ; the Temperature of the Sea, 66 ; on the Temperature of the Med- 

 iterranean Sea near the Coast of Algeria, 69 ; the Force of Sea Weaves, 123 ; 

 Eifect of Tides on the Rotation of the Earth, 130; Deep-sea Soundings by 

 Photography, 151. 

 (b.) METEOROLOGY. 



General Climatology : Meteorology in Germany, 78 ; Meteorology of the 

 Sieben-Gebirge, 79 ; Award to the Army Signal Service, 109 ; the Climate 

 Preceding the Glacial Epoch, 110; the Climate and Trees of Sacramento 

 Bay, 111; Climatic Changes in Scotland, 116; Climate of the Caucasus, 

 123; the Winds and Rains of India, 126; Rainfall, Winds, and Pressure in 

 Italy, 129 ; Constitution of the Atmosphere over the Libyan Desert, 130 ; 

 Magnetic Particles in Atmospheric Dust, 132 ; on the Height of the Aurora 

 Borealis, 132 ; Iron in Atmospheric Dust, 133. Atmospheric Electricity : 

 Dry Thunder-storms, 128; Frequency of Thunder-storms in Europe, 129; 

 Atmospheric Electricity^, 170 ; Lightning from a Clear Sky, 171 ; Protec- 

 tion against Lightning Strokes, 171 ; Lightning-conductors, 172. Atmos- 

 pheric Pressure and the "Winds : The Hurricane of September 9th to 

 17th, 1875, 97 ; Wind Velocity and the Barometric Gradient, 100 ; the Me- 

 chanical Theory of Cyclones, 101 ; the Monsoon, 102 ; Origin of Cold Waves 

 of Air, 104 ; the Upper Currents of the Atmosphere, 106 ; Periodicity of 

 Hurricanes, 112 ; the Severe Storm of March 12, 1876, 114 ; Barometric 

 Pressure during Winds, 115; the Eastward Progress of Storms, 124; Hail- 

 storms in France, 125 ; Origin of Cyclones, 127 ; the Bora of Southern Rus- 

 sia, 129; Relation of the Phases of the Moon to Atmospheric Pressure, 133. 

 Temperature : Nocturnal Radiation, 72 ; the Temperature of the Air, 

 105; Temperature Observations in Italy, 129; Schott's Tables of Atmos- 

 pheric Temperature, 134. Moisture : Rainfall of Bohemia, 93 ; IMoisture 

 in the Atmosphere, 94 ; the Observation of Polar Bands, 95 ; the Direction 

 of Cirrus Clouds, 98; Tables for Computation of Relative Humidity, 110; 

 Clouds and Winds as Observed from Balloons, 112; Dufour's Hygrometric 

 Studies, 113; the Formation of Snow as Observed from Balloons, 118; Red 

 Snow on the Pic-du-lNIidi, 125; Dalton's Law, and the Constitution of the 

 Atmosphere, 105. Observatories and Instruments : Time of Setting Self- 

 registering Instruments, 95 ; on the Wet and Dry Bulb Thermometer, 96 ; 

 the New Physical Observatory near St. Petersburg, 96 ; a very Delicate 



