Again, in the Smithsonian Contributions, vol. x., 1858, Mr. A. Schott, in his discussion of Dr. Kane’s observations at Van Rensselaer Harbour, in 1854, remarks—“In conformity with the supposed periodicity of this phenomenon as recognized by Professor Olmstead, no brilliant and complete Auroras have been seen; with an exception of very few, they may all be placed in his fourth class, to which the most simple forms of appearances have been referred.” The following statement is given in the same page as a footnote:—“The processes have no apparent connexion with the magnetic dip, and in _no_ case did the needle of our unifilar indicate disturbance.” * * * * * The following description of the Aurora observed on 21st November, 1875, is given by Commander Markham and Lieut. Giffard, in their abstract of observations at Floeberg Beach:— “Between 10 and 11 P.M. bright broad streamers of the Aurora appeared 10° or 15° above the north horizon, stretching through the zenith, and terminating in an irregular curve about 25° above the south horizon, bearing S.S.W. During the Aurora’s greatest brilliancy the magnet was observed during five minutes to be undisturbed.” [_Note._—I applied for a loan of the lithographic stones to enable me to give copies of the three diagrams of Auroræ referred to in the Arctic “Results;” but the Lords Commissioners of H.M. Treasury refused this, except on the terms of my paying one third of the original cost of production of such diagrams. I did not think it worth while to accept these conditions. Only one of the drawings has any special interest; and this is a “curtain” Aurora, similar to that figured on Plate II. of this work.—J. R. C.] APPENDIX D. THE AURORA AND OZONE. [Sidenote: Aurora and ozone. Dr. Allnatt’s notes and conclusions deduced therefrom.] While Part I. was in the press, Dr. Allnatt, formerly of Frant, and for many years the well-known meteorological contributor to ‘The Times’ newspaper, kindly placed at my disposal his large series of notes. Upon an examination of these we came to the following conclusions:— 1. That Auroral periods are also periods of comparative abundance of ozone. 2. That instances are by no means wanting in which an abnormal development of ozone appears to be coincident with the manifestation of an Aurora. [Sidenote: Year 1870 remarkable for sun-spots, auroræ, and ozone.] In reference to the first point, it is found, as the result of an examination of Dr. Allnatt’s notes, that particular years and months are notable at once for Auroræ and for ozone in abundance. 1870 was one of these years, and was specially recorded by Dr. Allnatt, in his ‘Summary for the Year,’ as remarkable for sun-spots, Auroræ, and ozone. [Sidenote: Particulars of some of the monthly records.]