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d-.ffercnt courftrles from the Yenlfei to the Lena ; fo that no 

 doubt of its truth can remain. This feems indeed to be the 

 real birth-place of the aurora borealis." Tliis account of 

 the noifes attending the aurora borealis, allowing for fome 

 degree of exaggeration, has been corroborated by other 

 teftimonics. A perfon, who refided feven years at Hudfon's 

 Bay, confirms M. Gmelin's relation of the fine appearance 

 and brilliant colours of the northern lights, and particularly 

 of their rulhing noife, which he affirms he has frequently 

 heai-d, and compares it to the found produced by whirling 

 round a flick fwiftly at the end of a firing. A fimilar noife 

 has alfo been heard in Sweden. Mr. Nairne alfo, being in 

 Northampton, at a time when the northern lights were re- 

 markably bright, is confident he perceived a liiffing or whiz- 

 zing found. Mr. Belknap, of Dover, in New Hampfhire, 

 North America, teflifies to this faft. American Tranf. 

 vol. ii. p. 196. M. Cavallo fays that the crackling noife is 

 diftinftly audible, and that he has heard it more than once. 

 Elem. of Nat. and Exper. Pliilof. vol. iii. p. 449. See alfo 

 Muffchenbroek Introd. Philof. vol. ii. p. 1056. § 2495. 

 Beccaria dell' Eleftricifmo Artif. et Nat. p. 221. 



Similar lights, called aurora aiijirales, have been long 

 fnice obferved towards the foutli pole (fee Phil. Tranf. 

 N^46l. § 23, 24, and 25. and vol. liv. N° 53.) ; and their 

 exidence has been more lately afcertained by Mr. Forltcr, 

 who affures us, that, in his voyage round the world with 

 captain Cook, he obferved them in high fouthern latitudes, 

 though attended with phenomena fonievvhat different from 

 thofc which are feen here. On Feb. 17, 1773, in fouth lat. 

 58'', " a beautiful phenomenon (he fays) was obferved dur- 

 ing the preceding night, which appeared again this and fe- 

 veral following nights. It confifted of long columns of a 

 clear white light, fhooting up from the horizon to the eafl- 

 ward, almoft to the zenith, and gradually fpreading on the 

 whole fouthern part of the flcy. Thefe columns were 

 fometimes bent fideways at their upper extremities ; and 

 though in mofl refpefts fimilar to the northern lights {au- 

 rora borealis) of our hemifphere, yet differed- from them in 

 being always of a whitifli colour, whereas ours alfume va- 

 rious tints, efpecially thofe of a fiery and purple hue. 

 The flcy was generally clear when they appeared, and the 

 air fiiarp and cold, the thermometer flanding at the freez- 

 ing point." 



The periods of the appearance of thcfe northern lights 

 are very inconflant. In fome years they occur very fre- 

 quently, and in others they are more rare ; and it has been 

 obferved that they are more common about the time of the 

 equinoxes than at other feafons of the year. 



Dr. Halley (fee Philof. Tranf. N" 347- p. 4^6. or Abr. 

 vol. iv. p. 138.) has coUefted to^^ether fcveral obfervations, 

 which form a kind of h\{\orj of this phenomenon. After 

 having particularly defcribed the various circumllances which 

 attended that obferved by himfelf and many others in March 

 1716, and which was fii'gvil.irly brilliant, he proceeds with 

 informing us, that the fiiii: account of fimilar phenomena 

 recorded in the Englifh annals, is that of the appearance 

 -which was noticed Jan. 30, 1560, and called " burning 

 fpears" by the author of a book inlitled " A Defcriptioii 

 of Meteors," by W. F. D. D. reprinted at London, in 

 1654. The next appearance of a hke kind, recorded by 

 Stow, occurred on Odober 7, 1564. In 1574, as Camden 

 and Stow inform us, an aurora boreahs was feeu for two fuc- 

 ceffive nights, viz. 14th and 15th of November, with ap- 

 pearances fimilar to thofe obferved in 1 7 16, and v>hich are 

 now commonly noticed. The fame phenomenon was twice 

 feen in Brabant in 1575, viz. on the 13th of February and 

 the '8th of September; and the circumdances attendmg it 



Vol. in. 



were defcribed by Cornelius Gemma, who comparM them 

 to fptars, fortified cities, and armies fighting in the air. hi 

 the year 15S0, M. Mafllin obferved thefe phafmata, as he 

 calls them, at Baknang, in the county of Wirtemberg, ia 

 Germany, no lefs than fcven times in the fpace of twelve 

 months; and again, at fcveral different times, in 158 1. 

 On September 2d, 162 1, the fame phenomenon was feen 

 over all France ; and it was particularly defcribed by Gaf- 

 ftiidus, in liis " Phyfics," who gave it the name of " au- 

 rora borealis." Another was feen all over Germany, in 

 Nov. 1623, and was defcribed by Kepler. Since that time, 

 for more than eighty years, we have no account of any 

 fuch phenomenon cither at home or abroad. In 1 707, Mr. 

 Neve obferved one of fmall continuance in Ireland ; and in 

 the fame year, a fimilar appearance was feen by Romer at 

 Copenhagen ; and during an interval of eighteen months, in 

 the years 1707 and 1708, this fort of liglit had been feen 

 no lefs than five times. Hence it fliould feem, fays Dr. 

 Halley, that the air, or earth, or both, are not at all times 

 difpofed to produce tliis phenomenon, though it is pofCble 

 it may happen in the day time, in bright moon-fhine, or in 

 cloudy weather, and fo pai's unobfervcd. Dr. Halley fur- 

 ther obferves, that the auroi-a borealis of 17 16, which he 

 defcribed, was vifible from the well of Ireland to the con- 

 fines of RulTia, and to the ead of Poland ; extending at 

 leall near 30^ of longitude, and from about the 50th degree of 

 north latitude, over almoll all the north of Europe ; and in all 

 places at the fame time, it exhibited appearances fimilar to 

 thofe which he obferved at London. He regrets, however, 

 that he was unable to determine its height for want of con- 

 temporary obfervations at different places. Father Bofco- 

 vich has determined the height of an aurora borealis, ob- 

 ferved on the 1 6th of December 1737, by the marqui* 

 of Poleni, to 'have been 825 miles; and Mr. Bergman, 

 from a mean of thirty computations, makes the average 

 height of the aurora boreahs to be 72 Sw^difh, or (fup- 

 pofing a Swedifh mile to he about 6{ Englifh miles) 46$ 

 Englilh miles. Euler fui>pofes the height to be feveral 

 thoufands of miles ; and NIairan alio affigns to thefe phe- 

 nomena a very elevated region, the far greater number of 

 them being, according to him, about 200 leagues above 

 the furface of the earth. Dr. Blagden, fpeaking of the 

 heightof fome fiery meteors (Phil. Tranf. vol ixxiv. p. 227.), 

 fays, that " the aurora boreahs appears to occupy as high, 

 if not a higher region, above the furface of the earth, a« 

 may be judged from the very dillant countries to which 

 it has been vifible at the fame time ;" he adds, that "the 

 great accumulation of eleftric matter feems to lie beyond 

 the verge of our atmofphere, as eftimated by the cetfatioa 

 of twilight." However the height of thefe meteors, none 

 of which appear to have afcended fo high as 100 miles, 

 is trivial, compared with the elevati.ins above afcribcd to 

 the aurora boreahs. But as it is difficult to make fuch 

 obfervations on this phenomenon as are fufficient to afibnl 

 a juil eflimate of its altitude, they mull be fubjeft to con- 

 fiderable variation and to material enor. It is not impro- 

 lable, that tlie highed regions of the aurora borealis are 

 the fame with thofe in which fire-balls move ; more efpe- 

 cially as Dr. Blagden informs us, that inilances are re- 

 corded, in which the northern lights have been feen to 

 join, and form luminous balls, darting about with great 

 velocity, and even leaving a train behind like the common 

 fire-balls. This ingenious author, however, conjecturing 

 that diflinft regions are allotted toihe eledrical phenomena 

 of our atmofphere, afhgns the appearance of tire-balls to 

 that region which lies beyond the limits of our crcpufcular 

 atmofphere ; and a greater elcTation above the earth to tliat 

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aecumuLiUoa 



