Kerguelen’s voyage to the north. 7^5 haul it. The wind getting round to the eail and blowing hard, the officer of the watch came to inform me, that he had taken in the forefail on account of its blowing hard from the call to E. S. E. with a very high fea. As the wind was favourable for re- turning to France, as I had not feen any thing of the filling veffiels for fome days, as the feafon for the fifhery was far advanced, and the continual fogs did not allow of my rendering any further affiftance to the French fhips, I fleered W. S. W., forefails and topfails fet to pafs between Iceland and the iilands of Ferro, and thence to continue my courfe for Breft. The firft of September, the wind eaft very frefli at noon, I took an obfervation, and found myfelf in latitude 6o° 8', and in longitude by reckoning 150 58' W. of Paris, The middle of the bank of which I fpoke in the beginning of my journal bore W. quarter S. W. exaCtly, twenty-five leagues diftant, and the ifland of Rokol at the S., forty-five leagues diftant: the ifland of Rokol is not marked in any French chart, but I am certain of its exiftence. I have requefted M. Beilin to infert it; its fituation.is in latitude 570 ^o', and longitude 160 o' W. This ifland is very healthy ; it is a-fharp rock, which, at four leagues diftance, looks like a fliip ; it has frequently been miftook for one. Eaft of Rokol ifland, a quarter of a league away from fhore, is a rock under water, with breakers. Under nearly the fame latitude as Rokol, but much more to the W., is another ifland. It is Bufs Ifland j it is not either on the French charts, but it exifts in latitude 58° o', longitude 28° W. On the night between the firft and the fecond, we faw an Aurora Borealis, which afforded us the mod beautiful fpeCtacle that nature can difplay. From ten in the evening until one in the morning, the heavens were on fire throughout the arCtic hemifphere, the night was as brilliant as the day ; I read a letter at midnight as eafily as I could have done at noon. We firft of all faw a luminous cloud in the form of an arch, which occupied half the firmament. From this about eleven o’clock rofe columns perpendicular to the horizon, and alternately white and red. The upper part of thefe columns towards midnight changed into fheaves of a flame colour, from the centre of which arrows of light iffued into the air like rockets ; at length after midnight, thefe columns, which were arranged with fuch admirable fym- metry, were confounded all at once in a brilliant chaos of cones, pyramids, radii, fheaves, and globes of fire. This celeftial appearance difappeared gradually j but the air was full of light even till day. Phenomena of this defcription have been feen in all ages and countries; but what are , their origin ? Why are they obferved towards the north ? As every one is allowed to have his own fyftem, I fhall hazard a conjecture on the probable caufe of the aurora bore- alis, called fo from its luminoufnefs refembling that of dawn, although more com- monly known by the name of the northern lights, on acccount of their being feen in the north. 1 mo, 1 imagine the matter of the aurora borealis to be the fame as that of lightning or eleCtricity. 2do, That the diurnal motion of the earth occafionsa continual flux of this matter towards the poles ; which makes thefe meteors molt vifible in the neighbouring regions. 3tio, That a certain denfity, temper, and particular conftitution of air be requifite to caufe to approach, heap together, and comprefs the igneous particles fo as by their fermentation to produce thofe fheaves, rockets, and luminous columns which are peculiar to the aurora borealis. 4to, That all the rapid movements, the lateral divergencies, the fudden appearance of columns, &c. refult from their mutual and al- ternate attradion and repulfion, a natural property of eleCtric fire, as is proved by the alternate attraction and repulfion of gold leaves and light bodies by eleCtrical globes. $to, That if this meteor appear but rarely, it is becaufe the air poflefles feldom the re- quifite denfity, or is properly conftituted to produce it. vol. 1. 5 h The

(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