November, 1809. Account of some luminous Meteors seen during a Thunder Storm. In a letter from James Staveley, Esq.
Sir,
Retiring rather late to bed last night, and throwing up the window to admire the beauty of the lightning, I was struck with the appearance of the sky, the grandeur and singularity of which I never remember to have been equalled. The time was about half past one o'clock. Considering that facts of this kind are at all times acceptable to the meteorologist, and that this may perhaps serve to elucidate some of the mysteries of that science yet unfathomed, if you have no better account of the phenomenon, may I offer this for a place in your valuable Journal?
The whole surface of the heavens seemed covered with one unbroken mass of black pitchy cloud, in which the very vivid flashes of lightning, that almost instantaneously succeeded each other, showed no break; and from which, but from inferior regions, they did not seem to issue. Over, or rather (to speak more properly) below this apparent surface, were spread light and flocky clouds, broken into large fleeces, white and apparently luminous throughout. I looked round that I might find whence proceeded the light that illuminated them; for they seemed as summer clouds in a bright sun, and as the clouds have appeared today. I could perceive no light. Every other part of the hemisphere was totally dark.
Looking fixedly at them, I fancied, that they seemed full of little dazzling and dancing specks of light, that sometimes shone as stars peeping through a misty cloud. Some of these increased gradually, and as gradually died away. One in particular became more and more distinctly visible, and increased in size, till it reached the brilliancy and magnitude of Venus, as she shines in a clear evening; and yet, there seemed no body of the light. At first I thought it must be some star; and it was with difficulty, that I renounced the idea. But such it could not have been; for when these clouds had passed away, and when the intensity of the black masses above became diminished, when they seemed only concealed by a dark and thick haze, none of them became visible. To be certain that the motion, that, I fancied, I observed it to have, did not proceed from the motion of the cloud, and was not deceitfully produced to me, from the swimming and indistinctness of vision necessarily occasioned in my eyes by the quick and vivid flashes of lightning, that encircled the whole horizon, I brought the meteor to a bearing with the window frame, and by that means distinctly ascertained its movement, and, that it was with considerable rapidity. I observed it coast, if I may use the expression, and, having again become stationary, diminish from its full splendor till it disappeared. Its duration must have been of minutes.
After a short interval I had an opportunity of observing another of these meteors in a similar cloud, though at a considerable distance; and of which, though it behaved much as the former had done, I was not able so distinctly to mark the motion.
During this time, these, and during the space of half an hour at least, similar clouds, were full of these little luminous innumerable points, which, playing incessantly, gave them an appearance similar to that, which is exhibited in a clear sky by the galaxy.
I have already said, that, when these had passed away, and the pitchy clouds also, which moved in the same direction, though not so rapidly, I could discern no stars whatever, and I took no small pains to spy out any, as they might have furnished me with a solution to the phenomenon. There was no flash of lightning broke from these clouds, but they emitted much light of a pale phosphoric colour, and such seemed the kind of light, that formed the body of the meteors. These clouds were at a very considerable distance beneath the higher stratum, and at no great elevation in the atmosphere, and though, after the interval of an hour, some of the most vivid flashes proceeded from this point in the heavens, yet do I conceive no connection between them and the clouds; as the latter had clean passed away, in an easterly direction, or with a few points north. Another thing I must mention, that as they tended to a greater distance, their brilliancy gradually diminished.
Along with this account I have enclosed a sketch of the phenomena, wherein, though guilty of an anachronism, having in the same moment of time shown the two meteors, I may be pardoned, as I have tolerably preserved the relative bearings of distances, and, as nearly as in such a sketch I could, the respective forms of the masses of cloud. The course of the first I have marked by making it luminous throughout; and note, that its first appearance was to the eastward, which in this sketch being the left hand, the position will be best seen when the sketch is held in the position of observation, above the head. It is on a very proportionally small scale, as at least 35 degrees are included within it, and the spots noted for the meteors proportionally as large, as was the halo that seemed to surround them. I am afraid to have dilated too much; yet, not seeing where I can curtail the description, leave for you, Sir, to lop off any superfluous matter.
There was no rain at the time of observation.
I am, Sir,
Your humble servant,
J.S.
Hatton Garden,
11 Aug. 1809.
P.S. As these meteors increased in size, they seemed to descend, and had much of that semblance, which the phantasmagorial spectres have, as they seem to approach the spectator.
No comments:
Post a Comment