The latitude, observed upon a point of the main land on the east side of Lucky Bay, from one supplement of the sun's altitude, was 33° 59' 45"; but as the supplement of the preceding day gave 39" less than the mean of both observations, I consider the true latitude to be more nearly 34° 0' 20" S.
The longitude from sixteen sets of distances of the sun east and west of the moon, of which the individual results are given in [Table II] of the Appendix to this volume, was 122° 15' 42"; but from the two best time keepers, in which, from the short period since leaving King George's Sound, I put most confidence, it will be more correctly 122° 14' 14" E.
Dip of the south end of the needle, taken on shore upon the granite rock, 66° 4' 0"
But I am inclined to think it was attracted by the granite; and that, had the needle been considerably elevated, it would not have shown more dip than at King George's Sound, where it was 64°.
The variation deduced from observations taken on shore, morning and evening, with three compasses placed on the same rock, was 2° 35' west; with Walker's meridional compass, 4° 55'; and with the surveying theodolite 0° 30' west.* An amplitude taken on board the ship, with the head east-south-east, gave 7° 25', which, reduced to what it should be with the head in the meridian, is 4° 26' west. The mean, and what I consider to be nearest the true variation in this neighbourhood, will be 3° 6' west.
[* It is remarkable, that the difference between these three kinds of instruments is directly the reverse here of what it was in King George's Sound.]
This is what I allowed upon the bearings taken with the theodolite upon the top of the hill behind the bay, and it appeared to be the same upon two small islands, one to the east and the other west, where Mr. Thistle took angles; but at Mondrain Island there seemed to be considerable differences.
Before entering the archipelago, the variation was observed to be 9° 21' west, with the ship's head east-south-east; but at three leagues to the east of Termination Island, in the following year, and with the head at east-north-east, it was no more than 3° 50' west. From the first, I should deduce the true variation on the west side of the archipelago to be 6° 28', and off Termination Island, from the second, to be 0° 57' west; both of which coincide with the other observations in showing the islands of the archipelago to possess a considerable degree of magnetic attraction.
The rise of tide in Lucky Bay was so trifling, that under the circumstances of our stay no attention was paid to it.
THURSDAY 14 JANUARY 1802