178 A VOYAGE TO [South Coast. 
iso2. The variation from an amplitude, observed when the ship's 
"March. 
Tuwday 3D. head was south-eastward, was 2° 50' east ; but the compass being 
upon a stand out of its usual place, I cannot deduce the true variation, 
but took it to be 4 0 40' east, nearly as found at the preceding 
anchorage. 
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 muc 
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 Kanguroo 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 i° 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 man- 
ner, to hills covered with grass ; and the 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 
