The illustrations are mainly from original drawings of my own. Those from other sources are acknowledged. Messrs. Mintern have well reproduced in chromo-lithography the coloured drawings illustrating the Auroræ, moon-patches, &c. 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.