TABLE OF CONTENTS/ 



3fr 



PREFACE Page iii 



GENERAL SUMMARY OF PROGRESS xix 



A. MATHEMATICS AND ASTRONOMY 1 



ASTRONOMY. 



Interstellar Space : Nature of its Medium, 7. The Stars : Movement in 

 Space, 7, 27 ; Spectroscopic Phenomena of Argus, 8. The Sun : Its true 

 Temperature, 1 ; Physical Condition, 2; Protuberances, 3, 5 ; Yellow bright 

 Line of Spectrum, 6 ; Magnesium in its Flame, 30 ; Bright Lines of Chro- 

 mosphere, 34; Eclipse of December, 1870,4,0,31,32; Future Eclipses, 7; 

 Relation to Magnetic Disturbances, 34 ; Spectroscopical Society, 3 ; Lecture 

 on, 32. The Planets: Leverrier on the larger, 9; Influence of, on the 

 Sun's Spots, 9 ; One supposed anterior to Mercury, 3 ; Transit of Venus in 

 1874, 11, 12, 39; Asteroids, 24, 33, 36; Saturn's Rings, 33; Spectrum of 

 Neptune, 38; of Planets generally, 9. The Moon: Photographs of, 24; 

 Change of Spots in Craters, 33. Meteoroids : Their Nature, 19, 27 ; of So- 

 lar Origin? 22; Fall of Aerolites, 22; Maskelyne on, 23. Comets : Planta- 

 mour's, 21; Encke's, 35; Biela's, 38; their Nature, 21, 27. The Aurora: 

 Its Nature, 13 ; its Spectrum, 14, 18 ; its Height, 16, 17 ; of February 4, 1872, 

 14, 17, 18. Observatories : Site for, 25 ; Sherman Station, 28 ; Report of 

 Washington, 26 ; of Dudley, 32 ; Telescope for Edinburgh, 25 ; Lexington, 

 Ya., 26 ; Proctor on, 29. Miscellaneous : Longitudes in the United States, 

 23 ; Proper Geographical Meridian, 158 ; late Advances in Astronomical 

 Knowledge, 24 ; Cable Announcements of Discoveries, 36. 



B. TERRESTRIAL PHYSICS AND METEOROLOGY 41 



TERRESTRIAL PHYSICS. 



The Land. Earthquakes: In California, 123 ; Self- regulating Indicator, 

 44 ; Volcanoes : Volcanic Sand in Chile, 56 ; Exhalations, 122 ; Change of 

 Level: In Northern Seas, 64, 122; near the North Pole, 115 ; on the Pata- 

 gonian Coast, 131; in the Andes, 155. The Ocean. Tides: Relation to 

 Height of Barometer, 41 ; Currents : Croll on, 41, 42 ; of the Black Sea, 57 ; 

 Depths : Steel Wire for Gauging, 56, 62 ; Temperatures : In the Atlantic 

 near the Equator, 43 ; between Cuba and Yucatan, 44 ; of Deep Seas gener- 

 ally, 57, 59 ; Apparatus for Recording, 71 ; Constituents : Amount of Car- 

 bonic Acid, 58, 59. 



* In the arrangement of articles in the body of the work, it was found difficult to 

 place them in systematic sequence. The effort has been made in the Table of Con- 

 teuts to rectify any misplacement of paragraphs, so as to bring together those most 

 nearly related, and in proper order. 



