Philosophical Transactions. For the months of October, November and December, 1714. - Part IV.

Ⅳ. An account of several extraordinary meteors or lights in the sky. By Dr. Edmund Halley, Savilian Professor of geometry at Oxon, and Secretary to the Royal-Society.

The theory of the air seemeth, at present to be perfectly well understood, and the differing densities thereof at all altitudes, both by reason and experiment are sufficiently defined; for supporting the same air to occupy spaces reciprocally proportional to the quantity of the superior or incumbent air, I have elsewhere proved that at 40 miles high the air is rarer than at the surface of the earth about 3000 times; and that the utmost height of the atmosphere, which reflects light in the crepusculum, is not fully 45 miles notwithstanding which, 'tis still manifest that some sort of vapours, and those in no small quantity, arise nearly to that height. An instance of this may be given in the great light the Society had an account of (vid. Transact. Sept. 1676) from Dr. Wallis, which was seen in very distant countries almost over all the South part of England. Of which though the doctor could not get so particular a reason, as was requisite to determine the height thereof, yet from the distant places it was seen in, it could not but be very many miles high.
So likewise that meteor which was seen in 1708. on the 31st of July, between nine and ten a clock at night, was evidently between 40 and 50 miles perpendicularly high, and as neat as I can gather, over Shereness and the Buoy on the Nore. For it was seen at London moving horizontally from E. by N. to E. by S. at least 50 degrees high, and at Redgrave in Suffolk, on the Tarmouth Road, about 20 miles from the East coast of England, and at least 40 miles to the Eastward of London, it appeared a little to the Westwards of the South, suppose by S. by W. and was seen about 30 degrees high, sliding obliquely downwards. I was shown in both places the situation thereof, which was as described, but could with some person skill'd in astronomical matters had seen it, that we might pronounce concerning its height with more certainty; yet, as it is we may securely conclude, that it was not many miles more Westerly than Redgrave, which as I said before, is above 40 miles more Easterly than London. Suppose it therefore, where perpendicular, to have been 35 miles East from London, and by the altitude it appear'd at in London, viz. 50 degrees, its tangent will be 42 miles, for the height of the meteor above the surface of the earth; which also is rather of the least because the altitude of the place shewn me, is rather more than less than 50 degrees; and the like may be concluded from the altitude it appear'd in at Redgrave, near 70 miles distant. Though at this great distance, it appear'd to move with an incredible velocity, darting, in a very few seconds of time, for about 12 degrees of a great circle from North to South, being very bright at its first appearance; and it died away at the end of its course, leaving for some time a pale whiteness in the place, with some remains of it in the track where it had gone; but no hissing sound as it past, or bounce of an explosion were heard.
It may deserve the honourable Society's thoughts, how so great a quantity of vapour should be raised to the very top of the atmosphere, and there collected, so as upon its accension or otherwise illumination, to give a light to a circle of above 100 miles diameter, not much inferior to the light of the moon; so as one might see to take a pin from the ground in the otherwise dark night. 'Tis hard to conceive what sort of exhalations should rise from the earth, either by the action of the sun or subterranean heat, so as to surmount the extream cold and rareness of the air in those upper regions; but the fact is indisputable, and therefore requires a solution.
Like to this, but much more considerable, was that famous meteor which was seen to pass over Italy on the 21st of March O.S. Anno 1676. about an hour and three quarters after sunset, which happen'd to be observed and well consider'd by the famous professor of mathematicks in Bononia Geminian Montanri, as may be seen in his Italian treatise about it, soon after published at Bononia. He observes that at Bononia, its greatest altitude in the S.S.E. was 38 degrees, and at Siena 58 to the N.N.W.; that its course by the concurrence of all the observers was from E.N.E. to W.S.W. that it came over the Adriatick Sea as from Dalmatia; that it crost over all Itality, being nearly vertical to Rimini and Savigniana on the one side, and to Leghorn on the other; that its perpendicular altitude was at least 38 miles; that in all places near this course, it was heard to make a hissing noise as it passed, ronzare, Far strepito comme unfunco artificiale, fisciare per aria comme un raggio di polve; that having past over Leghorn it went off to sea towards Corsica, and lastly that at Leghorn it was heard to give a very great blow, tuno di maggior rumore di grossa cannoata; immediately after which another sort of sound was hard like the rattling of a great cart running over stones, which continued about the time of a credo.
He concludes from the apparent velocity it went on with at Bononia, at above 50 miles distance, that it could not be less swift than 160 miles in a minute of time, which is above ten times as swift as the diurnal rotation of the earth under he equinoctial, and not many times less than that wherewith the annual motion of the earth about the sun is performed. To this he adds the magnitude thereof, which appeared at Bononia bigger than the moon i none diameter, and above half as big again in the other; which with the given distance of the eye, makes its real lesser diameter above half a mile, and the other in proportion. This supposed, it cannot be wondred that so great a body moving with such an incredible velocity through the air, though so much rarified as it is in its upper regions, should occasion so great a hissing noise, as to be heard at such a distance as it seems this was. But 'twill be much harder to conceive, how such an impetus could be impressed on the body thereof, which by many degrees exceeds that of any cannon ball; and how this impetus shou'd be determind in a direction so nearly parallel to the horizion; and what sort of substance it must be ,that could be so impelled and ignited at the same time; there being no vulcano or other spiraculum of subterraneous fire in the N.E. parts of the world, that we ever yet heard of, from whence it might be projected.
I have much considered this appearance, and think it one of the hardest things to account for, that I have yet met with in the phanomena of meteors, and am induced to think that it must be some collection of matter form'd in the ether, as it were by some fortuitous concourse of atoms, and that the earth met with it as it past along in its orb, then but newly formed, and before it had conceived any great impetus of descent towards the sun. For the direction of it was exactly opposite to that of the earth, which made an angle with the meridian at that time (the sun being in about 11 degrees of Aries) of 67 Gr. that is, its course was from W.S.W. to E.N.E. wherefore the meteor seem'd to move the contrary way; and besides falling into the power of the earth's gravity, and losing its motion from the opposition of the medium, it seems that it descended towards the earth, and was extinguish'd in the Tyrrhene Sea, to the W.S.W. of Leghorn. The great blow being heard upon its first immersion into the water, and the rattling like the driving a cart over stones being what succeeded upon its quenching; something like which is always observed upon quenching a very hot iron in water. These facts being dispute, I would be glad to have the opinion of the learned thereon, and what objection can be reasonably made against the above said hypothesis, which I humbly submit to their censure.
P.S. Since this was written, there has fallen into my hands an account of much such another appearance, seen in Germany, in the year 1686, at Leipsic, by the late Mr. Gottfreid Kirch, who was for many years a very diligent observer of the heavens and perfectly well instructed in astronomical matters. He in an appendix to his Ephemerides for the year 1688, gives us this remarkable relation in the following words.
Die 9 Jul. st.vct. hora 1 1/2 matutina, Globus ardens preditus in 8 1/2 gr. aquarii & 4 Gr. Sept. apparuit, qui per semiquadrantum hora immotus perstitit, cujus diameter semidiametrum luna circiter aquabat. Primo lux tanta erat, ut ejus ope fine candelis legere potuissemus; postea pedetentim in loco suo evinascebat. Phanomenon istud dicto tempore multis aliis in locis pariter visum est, prasertim Schlaizii, oppido undecium milliaribus germanicis abhine (i.e. a Lipsia) versus meridiem distante, altitudine circiter 60 Gr. ab horizonte meridiano.
At the time of this appearance the sun was in 26 1/2 Gr. of1, and by the given palce of the meteor, 'tis plain, it was seen about 3/4 of an hour past the meridian, or in S. by W. and by its declination it could not be above 24 degrees high at Leipsie, though the same, at Schlaize was about 60 Gr. high; the angle therefore at the meteor was about 36 Gr. whence by an easy calculus it will be found, that the same was not less than 16 German miles distant in a right line from Leipsick, and above 6 1/2 such miles perpendicular above the horizon, that is at least 30 English miles high in the air. And though the observer says of it immotus perstitit per semiquadrantem hora; 'tis not to be understood that it kept its place like a fixt star, all the time of its appearance; but that had no very remarkable progressive motion. For himself has at the end of the said Ephemerides given a figure of it, which he has marked Fig. D. whereby it appears that it darted downwards obliquely to the right hand, and where it ended, left two globules or nodes, not visible but by an optick tube.
The same Mr. Gottfried Kirch in the beginning of a German treatise of his, concerning the great comet which appeared in the year 1680, intituled2 printed at Nurenburg anno 1681, (of which perhaps we shall have further occasion to make mention) gives ua relation of such another luminous meteor seen likewise at Leipsick on the 22nd of May 1680. st. vet. about three in the morning; which though himself saw not, was yet there observ'd by divers persons who made various reports of it, but the more intelligent agreed that it was seen descending in the North and left behind it a long white streak where it has past. At the same time at Haarburgh the like appearance was seen in N.E. or rather N.N.E.; as also at Hamburg, Lubeck and Stralsund, all which are about 40 German miles from Leipsick; but in all these places, by person acquainted with the manner of properly describing things of this kind. So that we all can conclude from it is, that this meteor was exceeding high above the earth, as well as the former.
All the circumstances of these phanomena agree with what was seen in England in 1708, but it commonly so happens that these contingent appearances escape the eyes of those that are best qualified to give a good account of them. 'Tis plain however that this sort of luminous vapour is not exceedingly seldom thus collected; and when the like shall again happen, the curious are entreated to take more notice of them than has been hitherto done, that we may be enabled thereby better to account for the surprizing appearances of this sort of meteor.


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A pdf version of the entire text of the Philosophical Transactions of the Royal Society of London can be found here (this article begins on page 159).


  1. Please see the image that is in Gr. of: philo-trans-21 []
  2. Please see what is shown as the title: philo-trans []

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