tasman’s voyage of discovery.

441

variation of the needle with the leaft error poffible, the feamen take this method : theyobferve the point the fun is in, by the compafs, any time after its rifing, and then takethe altitude of the fun ; and, in the afternoon, they obferve when the fun comes to thefame altitude, and obferve the point the fun is then in by the compafs; for the middle,between thefe two, is the true north or fouth point of the compafs ; and the differencebetween that and the north or fouth upon the card, which is pointed out by the needle,is the variation of the compafs, and fhews how much the north and fouth, given bythe compafs, deviates from the true north and fouth points of the horizon. It appearsclearly from what has been faid, that, in order to arrive at the certain knowledge of thevariation, and of the variation of that variation of the compafs, it is abfolutely requifiteto have, from time to time, diftindl accounts of the variation, as it is obferved indifferent places : whence the importance of Captain Tafman’s remarks, in this refpedt,fufficiently appears. It is true, that the learned and ingenious Dodfor Halley has givena very probable account of this matter ; but as the probability of that account arifesonly from its agreement with obfervations, it follows, thofe are as neceffary and as im-portant as ever, in order to flrengthen and confirm it.

3. On the 6th of November, I was in 49 0 4' fouth latitude, and in the longitude of114° 56'; the variation was at this time 26° weflward ; and, as the weather was foggy,vvith hard gales, and a rolling fea from the fouth-weft and from the fouth, I concludedfrom thence, that it was not at all probable there fhould be any land between thofe twopoints. On November 15, I was in the latitude of 44 0 33' fouth, and in the longitude°f 140° 32'. The variation was then 18° 30' weft, which variation decreafed everyday, in fuch a manner, that, on the 21ft of the fame month, being in the longitude of158% I obferved the variation to be no more than 4 0 . On the 22d of that month, theneedle was in continual agitation, without refting in any of the eight points } which ledme to conjedture, that we were near fome mine of loadftone.

This may, at firft fight, feem to-contradidf what has been before laid down, as to thevariation, and the caufes of it: but, when ftriftly confidered, they will be found toa gree very well; for when it is afferted, that veins of loadftone have nothing to do withthe variation of the compafs, it is to be underftood of the conftant variation of a fewdegrees to the eaft, or to the weft : but in cafes of this nature, where the variation isabfolutely irregular, and the needle plays quite round the compafs, our author’s con-jedture may very well find place: yet it muft be owned, that it is a point far enoughfrom being clear, that mines of loadftone affect the compafs at a diftance; which,however, might be very eafily determined, fince there are large mines of loadftone in{ he ifland of Elba, on the coaft of Tufcany.

4 - On the 24th of the fame month, being in the latitude of 42 0 25' fouth, and inme longitude of 163° 50', I difcovered land, which lay eaft-fouth-eaft, at the diftance°t ten miles, which I called Van Diemen’s Land. The compafs pointed right towards*htsland. The weather being bad, I fleered fouth and by eaftalong the coaft, to the height44 ° fouth, where the land runs away eaft, and afterwards north-eaft and by north.^ the latitude of 43 0 ic/ fouth, and in the longitude of 167° 55', I anchored on theI °f December, in a bay, which I called the Bay of Frederic Henry. I heard, or atea ft fancied I heard, the found of people upon the fhore; but I faw nobody. All I^mt with worth obferving was two trees, which were two fathoms or two fathoms and? n half in girth, and fixty or fixty-five feet high from the root to the branches: theythr Ut a a kind of fteps in the bark, in order to climb up to the birds-nefts :tli 6 -^ e P s were ^0 diftance of five feet from each other; fo that we muft: conclude,at either thefe people are of a prodigious fize, or that they have fome way of climbingV QD. xi. 3 d trees