We arrived on board the sloop in the evening, with fourteen swans, in time to get a short distance down the river, before the ebb tide had done running; and no place more convenient than Risdon Cove having offered itself, we anchored there next day, and proceeded to complete our water, and refit the sloop for returning to Port Jackson. The late rains had so much increased the stream at the head of the cove, that our labour was much abridged; and in the evening of Dec. 30, every thing was completed.
This cove is the highest part of the Derwent to which a ship can advance. There is no danger in proceeding thus far, except off Shoal Point, about two miles below, on the western shore; and on the opposite side, near the echoing cliffs, there are 12 to 17 fathoms. Above Risdon Cove the mud flats commence, and will stop any vessel which draws more than ten or twelve feet; although there be, in some places higher up, from 5 to 8 fathoms. Mount Direction, on the north side of Risdon Cove, forms two round heads which are distinguishable from the entrance of the river, bearing N. 16° W. from Cape Direction. The latitude observed under the mount, from the moon's meridian altitude, was 42° 48' 12" south; variation of the azimuth compass on the south side of the cove, 8° 28', and of the surveying theodolite 9° 15' east; but I found it alter one or two degrees in different places, both in Norfolk Bay and in the Derwent, owing to partial attractions in the land.*
[* Upon the top of Mount Table, the compass has since been found to vary as much as 20°, from one part of the mountain to another.]
In Risdon Cove the tide rises between four and five feet, which is more, by at least a foot, than it appeared to be at the entrance of the river. The time of high water is about eight hours after the moon's passage over the meridian, or one hour later than in Adventure Bay.* In the narrow parts, above Sullivan Cove, the tides run with tolerable regularity, and with some degree of strength; but towards the entrance of the river, the water at the surface sometimes ran down twelve hours together, and at other times as much upwards, whilst the rise and fall by the shore were at the usual periods. These anomalies were probably occasioned by the wind, and seemed not to extend far below the surface; for I found a counter current at the bottom.
[* See Bligh's Voyage to the South Seas; page 53.]
The banks of the Derwent are not remarkably high, but the country in general may be termed mountainous. Mount Table, at the back of Sullivan Cove, is supposed to be three-quarters of a mile in height; nor do I think, from having seen it beyond the distance of thirty miles from the sloop's deck, that it can be much less. The publication of Mr. Bass' remarks upon the soil and productions of this part of Van Diemen's Land dispenses me from entering upon those subjects; it is sufficient to say, that the reports of them were so favourable as to induce the establishment of a colony on the banks of the Derwent, four years afterward; and that the discoveries which have since been made are marked in the chart.
1799.
The last day of December and the first of January were occupied in beating down to the entrance of the river.
Jan. 2. The wind blew strong from the south-east, with heavy rain; and finding no advantage could be made by beating in Storm Bay, we ran into D'Entrecasteaux's Channel, passed the large North-west Port, and anchored in Pruen Cove, in 4 fathoms. We landed, so soon as the rain cleared away, and found a small creek in which the water was fresh at a few hundred yards above where it falls into the cove. A tree had been felled on the bank, probably in 1793 or 4 by Mr. Hayes, who called this stream Amelia's River; but it would be very difficult to fill casks here, except when long continued rains should bring the fresh water to the entrance of the creek. The valley through which it comes from the westward, seemed to be of a rich, though damp soil.
On Jan. 3, having a breeze at north-west, we got under way at daylight; and after repassing the northern entrance of D'Entrecasteaux's Channel, steered across Storm Bay. At two clock I had the following bearings: