An Account of a Luminous Appearance in the Air at Dublin, on January the 12th, 1719/20 By Philip Percival, Esq; Brother to the Right Honourable the Lord Percival, and Communicated by His Lordship to the Royal Society

phorata: ut sanguinis consistentia integra servetur in pro- cessu, mali, quod fit acidis & terreis adstringentibus, ut Venenum ad peripheriam alliciatur, &c. Anno 1714. Emanuel Timonius, Constantinopolitanus. IV. An Account of a Luminous Appearance in the Air at Dublin, on January the 12th, 1719. By Philip Percival, Esq; Brother to the Right Honourable the Lord Percival, and communicated by his Lordship to the Royal Society. I Here send you a Sketch of an odd appearance in the Sky; it began about 10 a Clock on Tuesday last, but nothing very remarkable till about half an Hour after Eleven, when I was call'd out to see it, by the Servants, who had been looking at it about half a quarter of an Hour, and told me it looked just like Fire. But it ap- peared first to me in long streams of light, of a round Body, as at A, and very bright, tho' some were colou- red, as at A a. They came before the Wind, which was then West, as near as I could guess, there not being a Cloud in the Sky, and the brightest Moon I have known. We had Rain about Five, but at 6 a Clock the Night was clear. The Streams of Light A A, moved very slow, (there being but little Wind) but as they moved they joined, and, swelling out in the middle, formed themselves into the Figure b b B, continuing to advance slowly in that shape for about a Minute, when the two Ends b b, approaching near each other, as described by the prick'd Lines, the advanced part B, suddenly, and with great swiftness, ran back, and joining itself with the Ends b b, formed itself into the Figure C, quivering in the upper part, and darting down perpendicularly in sharp Points, as at D D D; and its Colour from a bright Light changed into the colours of a Rain-bow, but much fainter. It continued this way about a Minute, and then the sharp points D D D, gathering themselves up into C, it changed again into a square Sheet of Light, as at E, and swell'd out at F, as before at B; and advancing leisurely, repeated the same Scene as before, till it seem'd at a great distance to disperse itself into small thin light Clouds; tho'tis probable that to those who saw it in a like Situation, as it travell'd, it might make the same appearance as it did to me. I was very particular in observing it, and the next Morning drew it, and I think very exactly. I should have continued longer to look at it, (which I did for above a quarter of an Hour) but that it was excessive cold; the beginning of it was very like the Aurora Borealis, which has been very frequent this Winter here. V. Of the Infinity of the Sphere of Fix'd Stars. By Edmund Halley, L. L. D. R. S. S. The System of the World, as it is now understood, is taken to occupy the whole Abyss of Space, and to be as such actually infinite; and the appearance of the Sphere of Fixt Stars, still discovering smaller and smaller ones, as you apply better Telescopes, seems to confirm this Doctrine. And indeed, were the whole Sys-