A Letter from John Huxham M. D. F. R. S. to C. Mortimer M. D. Secr. R. S. Containing Observations on the Northern Lights, Seen Feb. 15 and 16, 1749-50

XII. A Letter from John Huxham M.D. F.R.S. to C. Mortimer M.D. Secr. R.S. containing Observations on the Northern Lights, seen Feb. 15 and 16, 1749-50. Dear Sir, Read June 21, 1750. YOU have herewith an Account of two uncommon Phenomena, which I observed last February. Feb. 15, 1749-50, in the Evening there was a very vivid Northern Light, which darted forth several beautiful, crimson, and fiery-colour'd Rays; Wind NWbN 1, Barometer 30.2; 50 Minutes past 8 a surprisingly bright and exceedingly white Arch, about the Breadth of a common Rainbow, appear'd in the Heavens, extending nearly from East to West; it reach'd within 5 or 6 Degrees of the Western Horizon, and ended about 8 or 10 above the Eastern. It pass'd exactly between Castor and Pollux, and directly over Aldebaran, which appeared plainly thro' it. Near the Top of the Arch several very lucid, white, short, vibrating Columns were attached to it; none of them seem'd above 6 or 7 Degrees long, and did not appear to communicate in the least with the Aurora borealis. The inclosed Figure (see Tab.I. Fig.5.) somewhat represents it. About 9h 12' the Arch vanished; but several white, bright, corruscating Nubeculae remain'd here and there in the Zodiac for 12 or 15 Minutes longer. The Aurora borealis continued more or less till Midnight: The next Morning the Wind was E.1x, Barom. 30.1. Feb. Feb. 16, about 7 p.m. we had another Aurora borealis, tho' not quite so fiery and luminous as that of the Night before: It continued till near 11. At 8h 56' p.m. exactly, such another Arch appear'd, very nearly of the same Extent and Direction, but not altogether so broad or lucid. This at first also passed between the two bright Stars of Gemini, but declin'd more and more to the Southward, till it was 2 or 3 Degrees to the South of Pollux. Its Western Limb, about 9, passed through the North Shoulder of Orion: It quite disappear'd about 10 or 12 Minutes after. — This had no Columns attach'd to it, as the former; tho' it was somewhat jagged and unequal towards the North near the Vertex. The Wind this Evening was E.2; the Barometer 29.9. The next Morning the Wind was SWbW1, the Barometer 29.9. Neither any Part of the Arch, or the attached Rays were coloured, but perfectly white, and exceeding bright. I am, dear Sir, with the greatest Respect, Plymouth, April 18, 1750. Your affectionate, and most obedient humble Servant, J. Huxham.