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-eastern most 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:
Wedge Island, highest part, S. 21½° E.
Thistle's Island, highest part, S. 29 W.
C. Catastrophe, former station on the S. E. point, S. 53½ W.
Stamford Hill, former station at the top, N. 86 W.
Sibsey Island, centre, N. 33 W.
Stickney Island, N. 11 W.
Spilsby Island, N. 17½ E.
The longitude deduced from these bearings was 30° 22" east, from the head of Port Lincoln, and that resulting from observations for the time keepers taken in the same place, was 30° 53"; showing a difference of no more than 0' 31" to the east, since quitting the port. This quantity in a sea observation is so small and uncertain, that I considered the time keepers to have gone correctly from March 4, when the last observations in Port Lincoln had been made, up to this time; and that the lunar observations taken in the interval might be reduced back to the head of the port by their means, and used to fix its longitude without any further correction.
Besides the bearings above given, there was a rocky islet four miles distant in the S. 78° W.; part of a ledge of low rocks which extended towards the north end of Thistle's Island, and may possibly be connected with the rock set from thence. This ledge is marked dangerous, in the particular chart.
Having satisfactorily ascertained the going of the time keepers, we tacked and stretched back for the coast on the east side of the gulph; but did not get sight of it before dark. At six on the following morning [SATURDAY 20 MARCH 1802],
Corny Point, dist. 5 or 6 leagues, bore N. 63½° E.
A cliffy head, distant 10 miles, S. 85 E.
Furthest extreme, a cliffy point, S. 21 E.
Wedge Island, eastern bluff, S. 49 W.
Thistle's Island, highest part, West.
An amplitude taken when the ship's head was south-by-east, gave variation 1° 25' east, and azimuths at south-south-east, 1° 10': the mean, reduced to the meridian, is 2° 13' east, or a few minutes more than had been found on the west side of the gulph, and half a degree less than off Point Pearce.
The tide appeared to set us along the shore to the southward, although, from what was observed at Thistle's Island, it should have been the time of flood. With its assistance, and the wind having become less unfavourable, we were enabled to make a course for the furthest land. This proved to be a cape, composed of three cliffy points, near the northern part of which lay a cluster of black rocks. The southernmost cliff bore at noon E. 4½° S. six or seven miles, and beyond it there was no main coast visible; but three small islands, with several rocks and a reef, were seen to lie as far as five miles to the southward, out from the cape.
Although the continuation of the main coast was not to be distinguished beyond the cape, yet there was land in sight at the distance of seven or eight leagues, from about south to S. 18½° W. Whether this land were an island or a part of the continent, and the wide opening to the eastward a strait or a new inlet, was uncertain; but in either case, the investigation of the gulph was terminated; and in honour of the respectable nobleman who presided at the Board of Admiralty when the voyage was planned and ship put into commission, I named it SPENCER'S GULPH. The cliffy-pointed cape which forms the east side of the entrance, and lies in 35° 18' south and 136° 55' east, was named CAPE SPENCER; and the three isles lying off it, with their rocks, Althorp Isles.
A line drawn from the nearest part of Cape Catastrophe to Cape Spencer will be forty-eight miles long, and so much is the entrance of the gulph in width. Gambier's Isles lie not far from the middle of the line; and if we measure upward from them, the gulph will be found, without regard to the small windings, to extend one hundred and eighty-five miles into the interior of the country. For the general exactness of its form in the chart I can answer with tolerable confidence, having seen all that is laid down, and, as usual, taken every angle which enters into the construction. Throughout the whole extent of the shores the water line was almost every where distinguished; the only exceptions being small portions at the head of Hardwicke and Louth Bays, of a bight near Point Lowly, and of the low land at the back of the great Eastern Shoal.