Early in the morning I went in a boat, accompanied by the naturalist, to examine more closely the head of the gulph. We carried from 4 to 3 fathoms water four miles above the ship, when it shoaled to fifteen and eight feet, which brought us to mud flats, nearly dry; but by means of a small channel amongst them we got within half a mile of the shore, and walked to it upon a bank of mud and sand.
It was then ten o'clock, and the tide was out; so that I judged the time of high water to be about seven hours after the moon's passage, or three hours later than at Kangaroo Island; and the ordinary rise appeared to be six or eight feet. An observation of the sun's meridian altitude from the artificial horizon showed the landing-place to be in latitude 34° 8' 52", and the uppermost water might be 30" less; whence the extent of this inlet, from Cape Jervis on the east side of the entrance, is 1° 30' of latitude.
Microscopic shells of various kinds, not larger than grains of wheat, were heaped up in ridges at high-water mark; further back the shore was sandy, but soon rose, in an undulating manner, to hills covered with grass; and several clumps of trees scattered over them gave the land a pleasing appearance from the water side. We set off in the afternoon for the Hummock Mount, which stands upon a northern prolongation of the hills on the west side of the inlet, and about eight miles from the water; but finding it could not be reached in time to admit of returning on board the same evening, I ascended a nearer part of the range to inspect the head of the inlet. It was almost wholly occupied by flats, which seemed to be sandy in the eastern part and muddy to the westward. These flats abounded with rays; and had we been provided with a harpoon, a boat load might have been caught. One black swan and several shags and gulls were seen.
I found the grass upon these pleasant-looking hills to be thinly set, the trees small, and the land poor in vegetable soil. The mountainous ridge on the east side of the inlet passes within a few miles of Hummock Mount, and appeared to be more sandy; but the wood upon it was abundant, and of a larger growth. Between the two ranges is a broad valley, swampy at the bottom; and into it the water runs down from both sides in rainy weather, and is discharged into the gulph, which may be considered as the lower and wider part of the valley.
This eastern ridge is the same which rises at Cape Jervis; from whence it extends northward towards Barn Hill and the ridge of mountains on the east side of Spencer's Gulph. If it joins that ridge, as I strongly suspect, its length, taking it only from Cape Jervis to Mount Arden, will be more than seventy leagues in a straight line. There are some considerable elevations on the southern part; Mount Lofty is one of them, and its height appeared nearly equal to that of Mount Brown to the north, or about three thousand feet. Another lies six or seven miles to the north-by-east of the Hummock Mount, near the head of this inlet, and seems to have been the hill set from Spencer's Gulph, at the anchorage of March 14, in the evening, when it was distant ten or eleven leagues and appeared above the lower range in front of Barn Hill.
From my station on the western hills of the new inlet, across to Spencer's Gulph, the distance was not more than thirty miles; but as I did not ascend the highest part of the range, the water to the westward could not be seen. Had the Hummock Mount been within my reach, its elevation of near fifteen hundred feet would probably have afforded an extensive view, both across the peninsula and of the country to the northward.
[SOUTH COAST. GULPH OF ST. VINCENT.]
In honour of the noble admiral who presided at the Board of Admiralty when I sailed from England, and had continued to the voyage that countenance and protection of which Earl Spencer had set the example, I named this new inlet the GULPH OF ST. VINCENT. To the peninsula which separates it from Spencer's Gulph I have affixed the name of YORKE'S PENINSULA, in honour of the Right Honourable Charles Philip Yorke, who followed the steps of his above-mentioned predecessors at the Admiralty.
WEDNESDAY 31 MARCH 1802
On the 31st at daylight we got under way to proceed down the gulph, and having followed the eastern shore in going up, I wished to trace the coast of the peninsula in returning; but the wind being nearly at south, it could only be done partially. At two in the afternoon we tacked in 3 fathoms from the eastern shoals, and at sunset in the same depth one mile from the western side; our distance from the head of the gulph being then about ten leagues, and the furthest land of the peninsula bearing S. 3° E. The western hills come down nearly to the water-side here, and have the same pleasant appearance as at the head of the gulph, being grassy, with clumps of wood scattered over them; the coast-line is somewhat cliffy, and not so low as the eastern shore.