Kerguelen's voyage to the north. 786 The mod celebrated philofophers have long maintained an opinion that the element of fire was aifperfed throughout exifience, and that folid and fluid bodies were abun- dantly impregnated with igneous particles. I conceive that the aether of Newton, the elementary fire of Boerhaave, and eleClric fire, are the fame fubftance, whofe different effects vary in proportion to the impulfe, agitation, direction, ffrength and quantity of the aflembled matter; hence the action of the fun on this fubftance produces the double advantage of light and heat. Thus the attrition of a globe of glafs reunites a certain quantity of it, which managed and directed with art, produces the various phenomena of electricity. Thus the fudden and violent collifion of two hard bodies elicits fparks, and the continual friCtion of two bodies of whatfoever defcription they may be, excites and originates elementary fire in fufficient quantity to inflame and confume any com- buftible matter expofe to its aCtion. When a great quantity of particles of fire is accumulated in condenfed clouds which comprefs and drive them together, the particles of fire then linking the one againft the other, inflame, fparkie, kindle into a blaze, and burft with explofion the prifon which inclofes them. Hence the flafli of lightning and the thunder clap ; and if the lightning be feen before the thunder be heard, it is becaufe the vibrations which expand from the igneous matter are more rapid of flight than the undulations of the air which bring us the found. When clouds have lefs denfity; when they pafs over fpace more lightly and more freely ; when they contain only a fmall quantity of the particles of fire, then, fhould they unite and clafh, together, they kindle into flame without explofion; they produce that filent lightning, and thofe falling ftars which fhine and difappear. When the atmo- fphere is not too much overfpread with clouds, and that they have no more than the denfity requifite for fuftaining and leading on the particles of fire in their fphere of mutual attraftion, without keeping them in, without heaping or preffing them, then no explofion fucceeds; but the particles of fire inflame.in the open air, and according to the different figures, though different confidence of the inflammable matter, and the different refraCtions of light, thofe globes, pyramids, radii, fheaves, and columns diffe- rently coloured of the aurora borealis are feen. The identity of the effence of light- ning and that of electricity, which has latterly been difcovered, and whofe refpeCtive effeCts are very various, greatly fupports the hypothefis, that the light of the fun, of lightning, eleClric phenomena, common fire, are only different effeCts of the fame caule differently aCted upon, difpofed, modified and circumflanced. Thefe auroras boreales are greatly ufeful to the inhabitants of the polar regions ; it feems as if nature was defirous by them to make amends for the abfence of the fun, and the privation of his beams. The fecond of September, having fleered S. W. for twenty-four hours, the wind going round from S. E. to N. by degrees, I took the latitude at noon, and found it 58° T, and longitude 17° 10' W. by reckoning. I was too much to the weft to make Rokol ifland, which is diflinguifhable at no gi-eater diflance than four or five leagues. Not feeing this ifland, I conjeClured that my reckoning was good, for had I been ten leagues more to the eaft, I muft have feen it ; and if, on the contrary, I had been the fame diflance more to the weft, I fhould have feen fome part of Iceland. The third, fourth, and fifth, and the fixth, the wind veered backwards and forwards from fouth to weft, blowing very frefli and a ftrong fea. When it blew from the weft I fleered fouth, when from the fouth, weft, in order to take advantage of the W. and S. W. winds. The fixth, at noon, the wind fkipped round to the W. N. W. in an in- flant. Latitude 51° io;, longitude 160 52' W. of Paris. After taking the latitude, I fleered S. quarter S. W., in order, before night-fall, to get fouth of the rocks called 7 Brazil,

(1) Band
(2) Band
(3) Saurblað
(4) Saurblað
(5) Blaðsíða 735
(6) Blaðsíða 736
(7) Blaðsíða 737
(8) Blaðsíða 738
(9) Blaðsíða 739
(10) Blaðsíða 740
(11) Blaðsíða 741
(12) Blaðsíða 742
(13) Blaðsíða 743
(14) Blaðsíða 744
(15) Blaðsíða 745
(16) Blaðsíða 746
(17) Blaðsíða 747
(18) Blaðsíða 748
(19) Blaðsíða 749
(20) Blaðsíða 750
(21) Mynd
(22) Mynd
(23) Blaðsíða 751
(24) Blaðsíða 752
(25) Blaðsíða 753
(26) Blaðsíða 754
(27) Blaðsíða 755
(28) Blaðsíða 756
(29) Blaðsíða 757
(30) Blaðsíða 758
(31) Blaðsíða 759
(32) Blaðsíða 760
(33) Blaðsíða 761
(34) Blaðsíða 762
(35) Blaðsíða 763
(36) Blaðsíða 764
(37) Blaðsíða 765
(38) Blaðsíða 766
(39) Blaðsíða 767
(40) Blaðsíða 768
(41) Blaðsíða 769
(42) Blaðsíða 770
(43) Blaðsíða 771
(44) Blaðsíða 772
(45) Blaðsíða 773
(46) Blaðsíða 774
(47) Blaðsíða 775
(48) Blaðsíða 776
(49) Blaðsíða 777
(50) Blaðsíða 778
(51) Blaðsíða 779
(52) Blaðsíða 780
(53) Blaðsíða 781
(54) Blaðsíða 782
(55) Blaðsíða 783
(56) Blaðsíða 784
(57) Blaðsíða 785
(58) Blaðsíða 786
(59) Blaðsíða 787
(60) Blaðsíða 788
(61) Blaðsíða 789
(62) Blaðsíða 790
(63) Blaðsíða 791
(64) Blaðsíða 792
(65) Blaðsíða 793
(66) Blaðsíða 794
(67) Blaðsíða 795
(68) Blaðsíða 796
(69) Blaðsíða 797
(70) Blaðsíða 798
(71) Blaðsíða 799
(72) Blaðsíða 800
(73) Blaðsíða 801
(74) Blaðsíða 802
(75) Blaðsíða 803
(76) Blaðsíða 804
(77) Saurblað
(78) Saurblað
(79) Band
(80) Band
(81) Kjölur
(82) Framsnið
(83) Kvarði
(84) Litaspjald