It is true, that Sir John Narborough did not succeed in opening this commerce, which promised, in appearance, so many advantages to the nation: But his disappointment was merely accidental; and his transactions on that coast, besides the many advantages he furnished to geography and navigation, are rather an encouragement for future trials of this kind, than any objection against them. His principal misfortune was in losing a small bark that accompanied him, and having some of his people trepanned at Baldivia. It even appeared, by the fears and precautions of the Spaniards, that they were fully convinced of the practicability of the scheme he was sent to execute, and were extremely alarmed with apprehensions for its consequences. It is said that Charles II. was so far prepossessed with the belief of the advantages that might redound to the public from this expedition, and was so eager to be informed of the event, on receiving intelligence of Sir John Narborough passing through the Downs on his return, that he had not patience to wait till his arrival at court, but went himself in his barge to meet him at Gravesend.
The two most famous charts hitherto published, [i.e. in 1745,] of the southern parts of South America, are those of Dr Halley, in his General Chart of the Magnetic Variation, and of Frezier, in his Voyage to the South Seas. Besides these, there is a chart of the Straits of Magellan and some parts of the adjacent coast, by Sir John Narborough, which is doubtless infinitely more exact in that part than Frezier's, and even in some parts superior to Halley's, particularly in regard to the longitudes of different places in these straits. We were in some measure capable of correcting, by our own observations, the coast from Cape Blanco to Terra del Fuego, and thence to the Straits of Le Maire, as we ranged along that coast, generally in sight of land. The position of the land to the northward of the Straits of Magellan, on the western side of Patagonia, is doubtless laid down very imperfectly in our charts; and yet I believe it to be much nearer the truth than any hitherto published; as it was drawn from the information of some of the crew of the Wager, which was shipwrecked on that coast; and as it pretty nearly agrees with what I have seen in some Spanish manuscripts. The channel, called Whale Sound, dividing Terra del Fuego, towards the western extremity of the Straits of Magellan, was represented by Frezier; but Sir Francis Drake, who first discovered Cape Horn, and the south-west parts of Terra del Fuego, observed that the whole coast was indented by a great number of inlets, all of which he conceived to communicate with the Straits of Magellan: And I do not doubt, when this country shall be thoroughly examined, that this conjecture will be verified, and that Terra del Fuego will be found to consist of several islands.
I must not omit warning all future navigators against relying on the longitude of the Straits of Le Maire, or of any part of that coast, as laid down by Frezier; the whole being from eight to ten degrees too far to the eastward, if any faith can be given to the concurrent evidences of a great number of journals, verified, in some particulars, by astronomical observations. For instance, Sir John Narborough places Cape Virgin Mary in long. 65° 42' W. from the Lizard, or about 71° 20' from London. The ships of our squadron, taking their departure from St Catharines, where the longitude was rectified by an observation of an eclipse of the moon, found Cape Virgin Mary to be from 70° 15' to 72° 30' W. from London, according to their different reckonings; and, as there were no circumstances in our run that could Tender it considerably erroneous, it cannot be estimated in less than 71° W. from London;[4] whereas Frezier makes it only 66° W. from Paris, which is little more than 63° from London. Again, our squadron found the difference of longitude between Cape Virgin Mary and the Straits of Le Maire to be not more than 2° 30', while Frezier makes the difference nearly 4°,[5] by which he enlarged the coast, from the Straits of Magellan to the Straits of Le Maire, to near double its real extent.[6]
Footnote 1: [(return)]
Isla Grande, supposed to be the Pepy's Island discovered by Cowley, is in lat. 46° 34' S. and is placed by Mr Dalrymple in long. 46° 40' W. while the illustrious navigator Cook makes its long. 35° 40' W. a difference of longitude of no less than eleven degrees.
Footnote 2: [(return)]
The centre of Falkland's Islands is in 51° 45' S. Janson's Islands, the most north-westerly of the group, or the Sebaldines, is in 51°; and Beauchene's Isle, the most southerly, in 53° S.E.
Footnote 3: [(return)]
The west extremity of this group is in long. 62° W. and the east extremity in 56° 43' W. so that their extent is 5° 12' in difference of longitude.E.
Footnote 4: [(return)]
Only 67° 40' W. from Greenwich.E.
Footnote 5: [(return)]
The Straits of Le Maire are in long. 65° 30' W. so that the difference is 2° 10'.
Footnote 6: [(return)]
Some farther critical observations on the geographical positions, as laid down by Frezier, Sir John Narborough, and Dr Halley, are here omitted, as tending to no use or information; these things having been since ascertained with much more accuracy.E.