Meteorological observations and essays / By John Dalton.

  • John Dalton
Date:
1834
Catalogue details

Licence: Public Domain Mark

Credit: Meteorological observations and essays / By John Dalton. Source: Wellcome Collection.

    91/280 (page 65)
    Notwithstanding the suddenness of the effulgence at the break- ing out of the aurora, there was a remarkable regularity observ- able in the manner.—Apparently a ball of fire ran along from E. to W. and the contrary, with a velocity so great as to be but barely distinguishable from one continued train, which kindled up the several rows of beams one after another; these rows were situate one before another with the exactest order, so that the bases of each row formed a circle crossing the magnetic meridian at right angles; and the several circles rose one above another in such sort that those near the zenith appeared more distant from each other than those towards the horizon, a certain indication that the real distances of the rows were either nearly or exactly the same. And it was further observable, that during the rapid lateral motion of the beams, their direction in every two nearest rows was alternate, so that whilst the motion in one row was from E. to W. that in the next row was from W. to E. The point to which all the beams and flashes of light uniformly tended, was in the magnetic meridian, and, as near as could be determined, between 15 and 20° south of the zenith.—The aurora continued, though diminishing in splendor, for several hours. There were several meteors (falling stars) seen at the time; they seemed below the aurora, and unconnected therewith.—It was seen at Keswick, Leeds, &c. with much the same circumstances ; but how far it extended I have not learned. The variation of the needle during the aurora, was not noticed. October 14.—I did not notice the aurora myself this evening ; there was thunder and lightning, both here and at Keswick, at the time of the aurora. October 18.—At Kendal. The aurora this night was an ob- long, luminous cloud, about 15 or 20° long, and 4 or 5° broad, bearing about SE, by E. and 10 or 20° above the horizon; its southern extremity was higher than its northern, and it evidently lay in the track of a great circle from E, to W.—It disappeared several times, and reappeared again almost instantly ; and several times waxed and waned without vanishing; no radiations shot from it. October 23.—At Kendal. The aurora this evening appeared as K