The general object of the several voyages round the world, undertaken by the command of his majesty, prior to that related in this work, was to search for unknown tracts of land that might exist within the bosom of the immense expanse of ocean that occupies the whole southern hemisphere.
Within that space, so few researches had been made, before our time, and those few researches had been made so imperfectly, that the result of them, as communicated to the world in any narration, had rather served to create uncertainty, than to convey information; to deceive the credulous, rather than to satisfy the judicious enquirer; by blending the true geography of above half the superficies of the earth with an endless variety of plausible conjectures, suggested by ingenious speculation; of idle tales, handed down by obscure tradition; or of bold fictions, invented by deliberate falsehood.
It would have been very unfortunate, indeed, if five different circumnavigations of the globe, some of them, at least, if not all, in tracks little known, and less frequented, had produced no discoveries, to reward the difficulties and perils unavoidably encountered. But the following review will furnish the most satisfactory proofs, that his majesty's instructions have been executed with ability; and that the repeated visits of his ships to the southern hemisphere, have very considerably added to our stock of geographical knowledge.
1. The south Atlantic ocean was the first scene of our operations. Falkland's Islands had been hitherto barely known to exist; but their true position and extent, and every circumstance which could render their existence of any consequence, remained absolutely undecided, till Byron visited them in 1764. And Captain Macbride, who followed him thither two years after, having circumnavigated their coasts, and taken a complete survey, a chart of Falkland's Islands has been constructed, with so much accuracy, that the coasts of Great Britain itself, are not more authentically laid down upon our maps.
How little was really known of the islands in the south Atlantic, even so late as the time of Lord Anson, we have the most remarkable proofs, in the history of his voyage. Unavoidably led into mistake, by the imperfect materials then in the possession of the world, he had considered Pepys's Island, and Falkland Isles, as distinct places; distant from each other about five degrees of latitude. Byron's researches have rectified this capital error; and it is now decided, beyond all contradiction, that, as Captain Cook says, "Future navigators will mispend their time, if they look for Pepys's Island in latitude 47°; it being now certain, that Pepys's Island is no other than these islands of Falkland."
Besides the determination of this considerable point, other lands, situated in the South Atlantic, have been brought forward into view. If the isle of Georgia had been formerly seen by La Roche in 1675, and by Mr Guyot, in the ship Lion, in 1756, which seems to be probable, Captain Cook, in 1775, has made us fully acquainted with its extent and true position; and, in the same year, he added to the map of the world Sandwich Land, hitherto not known to exist, and the most southern discovery that has been ever accomplished.
II. Though the Strait of Magalhaens had been formerly visited, and sailed through by ships of different nations, before our time, a careful examination of its bays, and harbours, and head-lands; of the numerous islands it contains, and of the coasts, on both sides, that inclose it; and an exact account of the tides, and currents, and soundings, throughout its whole extent, was a task, which, if Sir John Narborough, and others, had not totally omitted, they cannot be said to have recorded so fully, as to preclude the utility of future investigation. This task has been ably and effectually performed by Byron, Wallis, and Carteret; whose transactions in this strait, and the chart of it, founded on their observations and discoveries, are a most valuable accession to geography.
III. If the correct information, thus obtained, about every part of this celebrated strait, should deter future adventurers from involving themselves in the difficulties and embarrassments of a labyrinth, now known to be so intricate, and the unavoidable source of danger and delay, we have the satisfaction to have discovered, that a safer and more expeditious entrance into the Pacific Ocean, may be reasonably depended upon. The passage round Cape Horn has been repeatedly tried, both from the east and from the west, and stript of its terrors. We shall, for the future, be less discouraged by the labours and distresses experienced by the squadrons of Lord Anson and Pizarro, when we recollect that they were obliged to attempt the navigation of those seas at an unfavourable season of the year; and that there was nothing very formidable met with there when they were traversed by Captain Cook.
To this distinguished navigator was reserved the honour of being the first, who, from a series of the most satisfactory observations, beginning at the west entrance of the Strait of Magalhaens, and carried on with unwearied diligence, round Tierra del Fuego, through the Strait of Le Maire, has constructed a chart of the southern extremity of America, from which it will appear, how much former navigators must have been at a loss to guide themselves; and what advantages will be now enjoyed by those who shall hereafter sail round Cape Horn.
IV. As the voyages of discovery, undertaken by his majesty's command, have facilitated the access of ships into the Pacific Ocean, they have also greatly enlarged our knowledge of its contents.