Being arrived at the extremity of that part of the south coast of Terra Australis which had been previously explored, it may be useful, before entering on the unknown part, to compare my examination of it with what was contained in former charts. It will thence appear that the employment of fifteen days in running along the coast, more than would probably have been required had I kept at a distance, was not without some advantage to geography and navigation.
(Atlas, Plate II.)
At Cape Leeuwin, the largest Ile St. Alouarn of D'Entrecasteaux was seen to be joined to the main, and to form the south-western extremity of Leeuwin's Land, and of Terra Australis. The coast from thence to King George's Sound was more accurately investigated than the French admiral had an opportunity of doing and his omission of soundings supplied. Captain Vancouver's chart is superior to that of the French from Cape Chatham to the Sound; but that officer's distance from some parts prevented him from seeing them correctly. In the Sound, no particular advantage will be derived from the new survey, the plan given by Vancouver being sufficiently correct for nautical purposes, with the exception of the bar to Oyster Harbour, over which he had marked seventeen feet, but where thirteen now appeared to be the greatest depth. From King George's Sound to Point Hood the coast had been very indistinctly, and sometimes not at all seen by Vancouver; but I found it, speaking generally, to be laid down by D'Entrecasteaux with accuracy, though the bights in the land are marked somewhat too deep, from his distance not allowing the low beaches to be always distinguished. These trifling inaccuracies were remedied, the passages between Bald and Doubtful Islands and the main land opposite to them ascertained to be safe, and the omission of soundings along the coast remedied.
In Doubtful Island Bay the French chart does not give the north-western part sufficiently deep; but the coast from thence to the Archipelago of the Recherche, as also the reefs and rocks, were well distinguished, better perhaps than by me; but the usual want of soundings, with the exception of some distant ones by Vancouver, still continued. D'Entrecasteaux's chart appeared to be excellent in the western part of the archipelago, and good in the positions of the islands on the outskirts; so that I have, in some cases, borrowed from it. With respect to the inner islands and the main coast, it was necessarily defective, from the French ships having sailed round the archipelago, and not through the middle of it as I did in the Investigator. Here, my survey, though far from complete in the details, will afford much new information and useful also, since it has brought to light a well-sheltered cove affording wood and water, and two other tolerable anchorages at which some refreshments may be procured, and at one, quantities of salt in the summer season.
(Atlas, Plate III.)
From the archipelago eastward the examination of the coast was prosecuted by D'Entrecasteaux with much care, and with some trifling exceptions very closely; but as far as the 127th degree of longitude from Greenwich no soundings were given. These have been supplied, and a more minute description given of the coast. At the 129th degree the French ships seem to have been closer in with the land than was the Investigator; and it would appear by the track that they were also closer at the 30th, and at the head of the Great Bight, but these last are not corroborated by the soundings. From thence to the bay in which we anchored on the 28th, the Dutch chart of 1627 was the sole authority; and making allowances for the state of navigation at that time, it is as correct in form as could reasonably have been expected.
The latitudes and longitudes of the points and islands along the coast have been either verified or corrected, for there are commonly some differences between any longitudes and those of Vancouver and D'Entrecasteaux. The observations by which certain places, taken as fixed points, are settled in longitude, are mentioned at those places, as also are the corrections applied to the time-keepers for laying down the intermediate parts; and both are more particularly specified in the Appendix to this volume.
Monsieur Beautemps Beaupré, geographical engineer on board La Recherche, was the constructor of the French charts; and they must be allowed to do him great credit. Perhaps no chart of a coast so little known as this was will bear a comparison with its original better than those of M. Beaupré. That the Plates II and III in the accompanying Atlas, are offered as being more full and somewhat more correct, does neither arise from a wish to depreciate those of my predecessor in the investigation, nor from an assumption of superior merit; there is, indeed, very little due to any superiority they may be found to possess; but there would be room for reproach if, after having followed with an outline of his chart in my hand, improvements should not have been made in all or some of those parts where circumstances had not before admitted a close examination.