James Cook - A Journal of the proceedings of His Majesty's Bark Endeavour on a voyage round the world, by Lieutenant James Cook, Commander, commencing the 25th of May 1768 - 23 Oct. 1770: No. 117

Georges Island

in their being always accompanied with a large swell from the same Quarter & we find a much greater surf beating upon the Shore of the NW sides of the Islands situated just within the Limits of the Trade winds than upon any other part of them.
The tides are perhaps as inconsiderable in these Seas as in any part of the world a S or SSW moon makes high water in Royal Bay but the waters does not rise upon a perpendicular above 10 or 12 inches, except on some very Extraordinary occasions.
[Margin note] Variation of the Compafs [Compass]
The variation of the Compafs I found to be 4º.46' Easterly this being the mean result of a good number of Trials made by 4 of Dr Knight's needles belong to the [?Bismuth] Compasfs all of which I judged to be good ones & yet when applied to the Meridien line I found them not only differ one from another sometimes a degree half but the same needle would differ from itself more or lefs the difference sometimes amounting to half a degree both at the same time & on different days, this will in a great measure account for the seeming errors that may upon a nice examination appear to have been made in observing the Variation inserted in the Course of this Journal. This variablenefs in Magnatick Needles I have many times & in many places experienced both ashore & onboard of Ships & I do not remember of ever finding two Needles that would agree exactly together at one & the same time & place but I have often found the Same Needle agrees with itself for several Trials made immediately one after another, however all this is no sort of consequence to Navigation as the Variation of the Compafs can always be found to a degree of accuracy more than sufficient for all nautical purposes - I have before hinted that these people have an Extensive knowledge of the Islands situated in these Seas Tupia as well as several others hath given me an account of upwards of 70, but as the account they have given of their situation is so Vague & uncertain, I shall defer giving a list of them until I have learnt from Tupia the Situation of each Island with a little more certainty. Four of the Islands/Viz/Huaheine, Ulietea, Ohaha & BolaBola we were informed lay only one or two days sail to the Westward of Georges Island & that we might their procure Hogs, Fowls & other [indec.] Articles that we have been very sparingly supplied with at this last Island, & as the Ship's Company (what from the Constant hard duty they have had at this place & the too free use of Woman) were in a worse state of health than they were on our first arrival for by this time full half of them had got the Veneral disease in which Situation