Page:A Voyage to Terra Australis Volume 1.djvu/391

Spencer's Gulph.]

land distant thirteen miles, an amplitude gave 3° 15′ east. These different observations, which were all taken with the surveying compass, being corrected upon the principles and by the proportion explained in the Appendix No. II. to the second volume, will be respectively, 2° 51′, 4° 21′ furthest from the land, 2° 58′, 1° 41′ nearest the land, and 2° 1′ east. The mean is 2° 46′ east; which may be taken for the true variation at three or four leagues off Point Pearce in 1802; but close in with the shore, I suspect it was less by 1°, or perhaps 2°.

Having remained at anchor until the sun was high enough to admit of observations for the time keepers, we got under way at half past seven o'clock; and the coast round Corny Point being found to trend S. 27° W., nearly in the wind's eye, I stretched westward across the gulph towards Thistle's Island, in order to compare the time keepers with the longitudes of places before settled. Our latitude at noon, observed on both sides, was 34° 50′ 10″; Spilsby Island, the south-easternmost of Sir Joseph Banks' Group, was seen bearing N. 56° W., and the eastern bluff of Wedge Island, the central and largest of Gambier's Isles, bore S. 16½° W. Gambier's Isles, four in number besides two peaked rocks, had been first seen from the high land behind Memory Cove. They lie nearly in the centre of the entrance to the gulph; and the latitude of Wedge Island is 35° 11′ south, and longitude 136° 29′ east. Soon after four in the afternoon, I had the following bearings: The longitude deduced from these bearings was 30′ 22″ east, from the head of Port Lincoln, and that resulting from observations for