TABLE OF CONTENTS.

[PART I.]
THE AURORA AND ITS CHARACTERS.
[CHAPTER I.]
The Aurora as known to the Ancients:pp. [1-5].
[CHAPTER II.]
Some general Descriptions of Auroræ:pp. [6-15].
By Sir John Franklin:pp. [6], [7].
By Rev. James Farquharson:pp. [7], [8].
By Mons. Lottin (Lardner):pp. [8-11].
By Lieut. Weyprecht (Payer):pp. [11-14].
Article in ‘Edinburgh Encyclopædia:’pp. [14], [15].
[CHAPTER III.]
Some specific Descriptions of Auroræ:pp. [16-30].
Capt. Sabine’s Auroræ:p. [16].
Aurora seen at Sunderland, February 8th, 1817:p. [16].
Dr. Hayes’s Aurora, 6th January, 1861:pp. [16], [17].
Prof. Lemström’s Aurora, 1st September, 1868:pp. [17], [18].
Mr. J. R. Capron’s Aurora, October 24th, 1870:pp. [18], [19].
Mr. Barker’s red and white Auroræ, 9th November (1870?):p. [19].
Mr. J. R. Capron’s Aurora, February 4th, 1872:pp. [19], [20].
Cardiff, Aurora seen at:p. [21].
Mr. J. R. Capron’s Aurora, February 4th, 1874:pp. [21], [22].
Mr. Herbert Ingall’s Aurora, July 18th, 1874:pp. [22], [23].
Mr. J. R. Capron’s white Aurora, September 11th, 1874:pp. [23], [24].
Dr. Allnatt’s Aurora, June 9th, 1876:p. [24].
Herr Carl Bock’s Lapland Aurora, October 3rd, 1877:p. [25].
Rev. T. W. Webb’s Aurora:pp. [25], [26].
English Arctic Expedition, 1875-76:p. [26].
Aurora Australis:pp. [26-29].
Prof. Piazzi Smyth’s typical Auroræ:pp. [29], [30].
[CHAPTER IV.]
Phenomena simulating Auroræ:pp. [31-32].
Auroric Lights (Kinahan):pp. [31], [32].
Luminous Arch:p. [32].
[CHAPTER V.]
Some qualities of the Aurora:pp. [33-51].
Noises attending Auroræ:pp. [33], [34].
Colours of Aurora:pp. [35-37].
Height of Aurora:pp. [37-40].
Phosphorescence attending Aurora:pp. [41-44].
Aurora and Ozone:pp. [44], [45].
Polarization of Aurora light:pp. [45], [46].
Number of Auroræ:p. [46].
Duration of Aurora:p. [47].
Travelling of Auroræ (Donati):pp. [47], [48].
Geographical distribution of Auroræ (Fritz and Loomis):pp. [48], [49].
Extent and principal zone of the Aurora:pp. [50], [51].
[CHAPTER VI.]
Aurora in connexion with other Phenomena:pp. [52-69].
Auroræ and Clouds:pp. [52-54].
Aurora and Thunder-storms:pp. [54], [55].
Aurora and Magnetic Needle:pp. [55-58].
Auroræ, Magnetic Disturbances, and Sun-spots:pp. [58-62].
Aurora and Electricity:pp. [62-64].
Aurora and Meteoric Dust:pp. [64], [65].
Aurora and Planets Venus and Jupiter:pp. [66], [67].
Aurora and Zodiacal Light:pp. [67-69].
[CHAPTER VII.]
Aurora-like patches on the partially-eclipsed Moon:pp. [70-77].
[CHAPTER VIII.]
Aurora and Solar Corona:pp. [78-81].
[CHAPTER IX.]
Supposed Causes of the Aurora:pp. [82-87].
Prof. Lemström’s Theory:pp. [87], [88].
Theories of MM. Becquerel and De la Rive:p. [88].
M. Planté’s electric experiments:pp. [89], [90].
[PART II.]
THE SPECTRUM OF THE AURORA.
[CHAPTER X.]
Spectroscope adapted for the Aurora:pp. [91-93].
Spectrum of Aurora described:pp. [94-100].
Flickering of the green line:p. [100].
Mr. Backhouse’s graphical spectra of four Auroræ:p. [101].
Lord Lindsay’s Aurora-spectrum, October 21, 1870:p. [102].
Spectrum of the Aurora Australis:pp. [103], [104].
Professor Piazzi Smyth’s Aurora-spectra:p. [104].
Author’s Catalogue of the Auroral lines:pp. [104-106].
Theories in relation to the Aurora and its spectrum:pp. [106], [107].
[CHAPTER XI.]
The comparison of some Tube and other Spectra with the Spectrum of the Aurora:pp. [108-120].
Hydrogen-tube:pp. [108-110].
Carbon- and oxygen-tubes:pp. [110-114].
Geissler mercury-tube and barometer mercurial vacuum:pp. [114], [115].
Air-tubes:pp. [115], [116].
Phosphorescent tube:pp. [116], [117].
Spark in air:p. [117].
Spark over water:p. [117].
Phosphoretted-hydrogen flame:pp. [117], [118].
Iron-spectrum:p. [118].
Spectrum of mercury:p. [119].
Table of coincidences:p. [119].
[CHAPTER XII.]
Notes on Professor Ångström’s Theory of the Aurora-spectrum:pp. [121-127].
[CHAPTER XIII.]
The Oxygen-spectrum in relation to the Aurora (Procter and Schuster):pp. [128-131].
[PART III.]
MAGNETO-ELECTRIC EXPERIMENTS IN CONNEXION WITH THE AURORA.
Introduction: pp. [133-135].
[CHAPTER XIV.]
Examination of Geissler-tubes under action of the Magnet:pp. [136-146].
Nitrogen-tubes:pp. [136], [137].
Oxygen-tubes:p. [138].
Hydrogen-tubes:pp. [138], [139].
Water-gas tube:p. [139].
Ammonia-tube:pp. [139], [140].
Carbonic-acid tube:p. [140].
Chlorine-tubes:pp. [140], [141].
Iodine-tubes:pp. [141-143].
Bromine-tubes:pp. [143], [144].
Silicic fluoride-tubes:p. [144].
Sulphuric-acid tubes:pp. [144], [145].
Sulphur-tube:pp. [145], [146].
[CHAPTER XV.]
Effect of Magnet on a capillary Glass Tube:pp. [147], [148].
Action of magnet on a bar of heavy glass:pp. [147], [148].
[CHAPTER XVI.]
Effect of Magnet on wide Air (Aurora) tube:pp. [149-153].
Stratification (note on):pp. [149], [150].
Effect of magnet on Plücker (air-) tube:pp. [150-152].
Effect of magnet on Plücker tube (tin chloride):pp. [152], [153].
Effect of magnet on tin-chloride Geissler tube:p. [153].
[CHAPTER XVII.]
Effect of Magnet on bulbed Phosphorescent Tube:pp. [154-156].
Effect of magnet on small phosphorescent (powder) tubes:pp. [156], [157].
Lighting-up tubes with one wire only (Marquis of Salisbury’s observations):pp. [157], [158].
[CHAPTER XVIII.]
Action of the Magnet on the Electric Spark:pp. [159], [160].
[CHAPTER XIX.]
The Discharge in vacuo in Larger Vessels, and Magnetic Effects thereon:pp. [161-165].
Some of Baron Reichenbach’s magnetic researches tested:pp. [165], [166].
Summary of the foregoing Experiments and their Results:p. [167].
[CHAPTER XX.]
Some concluding Remarks:pp. [168-171].
[APPENDICES.]
A. References to some Works and Essays on the Aurora:pp. [173], [174].
B. Extracts from the Manual and Instructions for the (English) Arctic Expedition, 1875:pp. [175-181].
C. Extracts from Parliamentary Blue-book, containing the “Results derived from the Arctic Expedition, 1875-76:”pp. [182-188].
D. Aurora and Ozone:pp. [189-193].
E. Dr. Vogel’s Inquiries into the Spectrum of the Aurora:pp. [194-207].