페이지 이미지
PDF
ePub

as the effect of a southerly current, not being accounted for by the Charlotte's log.

But the Charlotte had two chronometers embarked, which, we are told by Capt. Hains, of the Hon. East India Company's service, performed exceedingly well; aud our best acknowledgments are due to that officer for the pains which he has taken to show the behaviour of these chronometers, which indeed appear to have gone remarkably well. Such attention to the subject is quite in accordance with that high character in these matters which has always distinguished the officers of the service to which he belongs.

We shall not trouble our readers with any comments on the discord. ances presented in the table, although we might remark on some wide differences which appear here and there. But we will turn to the last day: this presents a tolerable agreement in latitude as well as the day before, but along with it very wide differences in longitude. Therefore, as we have said, we shall leave them, and turn at once to what is recorded in the Charlotte's log of her chronometers, which if they have not done good service for the Charlotte, they have for us, in helping us to find the Bonetta rock. And what do they say? Why, that while the vessel is making a south course by her reckoning from the noon of Saturday to that of Sunday, the day she was lost, the mean of these chronometers shows a westerly set of 21 minutes of longitude. One of them shews a set of 27', and the other 15' to the westward. Even the day before when by the account the Charlotte had made 14' casting, the chronometers shew the same amount of westing! If our readers will refer to pages 680 and the following, this will be apparent to them.

Surely this was sufficient to open the eyes of any one entrusted with the charge of a ship! to the fact of her being influenced by a formidable current, the action of which can only be discovered by these valuable machines; for what purpose were they on board the Charlotte, but to detect the influence of currents, and to correct her reckoning.

Now the first step that would be taken in the prudent management of a vessel on approaching the position of a reputed danger, or at any rate a part of the ocean which has been fatal to so many vessels, would at least have been a careful look-out to avoid the same disastrous consequences, and such a direction of the vessel's course adopted as would have avoided it. A careful commander would have reasoned thus, when he made the discovery on Sunday at noon :-The chronometers have shewn a considerable set to the westward both to-day and yesterday, and I am not clear of the Cape Verdes. Will my present course keep me so ? A S.S.W. course from where I am in 17° 2' and 22°, the western most of my chronometers, will keep me clear of Bonavista, and I shall not keep further away till I am to the southward of this island; I can then alter course and make Mayo and St. Jago. Such would have been the determination of a discreet commander of the Charlotte.

But what did the Charlotte do? Only two hours after, when she was yet forty miles to the northward of Bonavista, the very elbow of the Cape Verdes, she keeps away two points more, and in consequence is brought up by the reefs off that elbow! Even if she had cleared Banavista we should have heard of her running against Mayo or St. Jago with such a course.

We have already shewn by the high authority of Major Rennell, by Baron Roussin, and by Sir Erasmus Gower, and also by the Charlotte's log and her chronometers, that she was within the influence of a strong southwesterly current, but we have deferred another evidence of it until we came to the consideration of that part of her voyage immediately preceding her loss when she was close to the Cape Verde Islands. The evidence to which we allude, although it might never have been seen on board the Charlotte applies most especially to her case. We mean a certain little chart which was published in this journal in 1839, containing the tracks of the Ætna in search of the Bonetta rock. Besides containing the tracks and soundings so carefully laid down by Captain Vidal, it shows also the currents by which his ship was influenced. A vessel cruizing about like the Ætna in search of a sunken rock, with her reckoning properly attended to, and astronomical observations for latitude and longitude properly made, can show the direction and force of a current, on which dependance may be placed, Now within about forty-five miles of the north-east side of Bonavista, we find the following currents on this chart:S. 71° W. 12' D. Lat. 3.9

Dep. 11:3
S. 30 w.

55
S. 38 W. 14

11.0

8.6 S. 40

7.7

6.4 S. 45

7:1

7.1 8. 17

13.4

14:1 West

130

11

10

[ocr errors]
[ocr errors][ocr errors][ocr errors][ocr errors][ocr errors]

Or, a mean distance of 12' in the twenty-four hours on the above course; or giving a current of about half a knot per hour.

It is true that there is a northerly set also on the chart, but the currents noted on it with the exception of this one are to the south-west.

We will now take the courses steered by the Charlotte from noon on the day she was lost, along with the westerly set shewn on the preceding day by the chronometer of about a mile an hour, and allow with this a set of S. 52° W., half a mile an hour. The case will stand thus: S. 70 W.

D. Lat. 12:9

Dep. 1-6
S. 39 W.

34.6
West

0.0

8.0 S. 52 W.

2:5

3.2

20.0

[merged small][ocr errors]

giving a course made good from noon to the time she struck $. 33° W. sixty miles. The westerly set of eight miles, or a mile an hour, is amply shown by the Charlotte's chronometers on the two preceding days; that of S. 52° W. four miles would have been but a just precaution when the vessel was running before the wind in the direction of the carrent. Then if we consider the Charlotte to have been in 17° 4' and 220 W., as shewn by her commander while on her voyage, by one of her chronometers, it will be seen by laying down this course that she will not even clear the eastera extreme of Bonavista ! So that a little acceleration of the current on approaching the island, as might be expected to take place, a little wild steering with an erroneous compass Toali be quite enough to set her on the reefs, lying between three and four miles off the north-east side of it. Indeed the distance sixty miles brings her within six miles of them.

So much for the result of the data afforded by the Charlotte's log. When there was even a possibility of such data being correct, which the result bas proved it to be, no seaman can say that the courses sbe was steering were justifiable

Now let us see what is said of the reefs off Bonavista :-in p. 270 of the Atlantic Memoir above quoted, we read that “the eastern side of Bonavista is partly enrironed by a reef; and on the north-east are the reef on which the Hartwell East Indianian was lost in 1787, and on which the Resolution, Captain Cook, was nearly driven by a southerly current."

We further find in the same page that there are three cays between which there is sufficient depth of water for ships to anchor inside of them; “ but many rocks are here scattered with only twelve or thirteen feet over them and four fathoms close along them.” Between two of the cays the channel is three-quarters of a mile broad, and has regular soundings from fifteen to fire fathoms, frequented by H.M.S. Bulldog in 1787, which vessel several times anchored, with one cay bearing N.E.b.E. and another S. W. in six or seven fathoms. It appears that there is also deep water between them and the shore.

Now the account giren of the reef and reported by the American Consul's letter in page 562 of our August number, states that “it is 300 feet in length, under water, in the shape of a crescent, open to the northward, and the sea breaks only at particular times of tide.” We should say at all times of tide, considering that there must always be a heavy sea on it, and the rise of tide being not more than 4 feet at the Cape Verde Islands.

Again the log says in page 681 “ breakers were seen close ahead," (what was the look out about that they were not seen till “close ahead') ship on the reef from ten to fifteen minutes," but the topsails, (the haliands having been let go by the run when the ship struck) and the courses were set and the ship forged off to the eastward, after which she just clears breakers on the lee bow." There is something more here than a single rock just under water. First it is a rock, then a reef, and now we have got two reefs, or a reef and afterwards (how long is not said) breakers which were just cleared. There is something more there after all than a single rock.

But we must pause for a moment and ask a question. The Charlotte bad studding sails set on both sides; those on the larboard side were set on the 17th, those on the starboard on the 19th. She bas the wind at N.N.E. and is steering S.W. Now the nearest way to throw ber up into the wind, would have been to have put her helun a-port; but it is put to starboard, and she has therefore to go round four points

more than necessary. Now, was this the consequence of hurry and confusion, or was it that there were certain other indications of danger on the starboard bow, which the reefs off the island would show by the surf breaking on them? This is best known to those on board. But we have a right to expect that to clear a solitary rock in the ocean such as the Bonetta is reported to be, she would take the shortest means of getting up to the wind; and this was not done!

Well, the Charlotte just clears the second breakers on the lee bow, and she heads about E.N.E. But she is a sinking ship from this time and is abandoned to her fate, half an hour after midnight. We have endeavoured to ascertain how much easting she really did make at this time; but our question is unanswered. Probably she may have made five or six miles, perhaps eight, (we should think not more) when the crew and passengers are in the boats, and we are told by the log “lay to until daylight,” when Bonavista is found to bear “N.W". Here we come at once to a most important statement, imparting to the chain of our reasoning, a strength, which could hardly have been expected in matters of this kind. The island of Bonavista bears N.W. Will our readers lay down the Charlotte's own position of the rock as stated in the Consul's letter in 16° 17' N. and 22° 21'W. From this position we will suppose her to have made good, about six miles due east; she was heading E.N.E. the variation and current would be against each other, therefore she may have made a good easterly course of six miles. Here the boats leave her as she foundered. Now the boats must have had some slight drift before daylight; say they drifted four miles to the S.W. Proin this position as Captain Hains observes, the island of Sal bears N.W. but that was too far off to be seen, and the boat must have drifted at least 16 miles further south, or 20 miles in all, at least, to bring even the northernmost part of this island to bear N.W. This again would be 20 miles off them and invisible in a boat, but the highest part of the island might have been seen at that distance ; and to bring that to bear N.W. they must have drifted at least 3 miles more to the S.W., making in all a drift of 23 miles in about five hours.

We may fairly conclude such a thing impossible among the Cape Verde Islands. But it would be quite possible to have the island bearing N.W. allowing the reef she struck on to be about four miles off the land, and that the vessel had made the same easting after she struck, and the boats had drifted south-west about four miles after leaving her. The island might then be about ten miles off them on the bearing of north-west. Now we know from experience that distances at sea are always overstated. A vessel will suppose herself twenty miles from a coast when she is much less. Could we arrive at the actual distance of the boat the next morning from the land, it would go far towards deciding the question. If it be admitted that the north-west bearing is correct, that, along with the reasoning which we have adduced is sufficient to determine it. But if that be stated to be incorrect, what part of the log is correct we would ask? No, we could admit of no such statement. The bearing is deliberately entered in the log; the log is brought home and delivered to the owner many days after, and we are bound to receive it as a true statement to the best of the master's judgment in common with the rest of the contents

of the log. Had the master taken the angle of elevation of the highest land of Bonavista, that would have enabled us to arrive at the distance of the boats from the land; but these things are never thought of, or if thought of, are seldom or never done on these occasions.

What then are our conclusions? It is shown by the reckonings of our correspondents, that the place of the rock assigned to it by her commander is incorrect, or else their own must be. It is shewn by the Charlotte's log and the observations, that she was under the influence of a south-west current, which current it is also shown, by the bigh and indisputable authorities we have quoted, is prevalent about the Cape Verde Islands. It is shown that there are two reefs instead of one, the Charlotte having struck on one, and getting off it about a quarter of an hour afterwards, just cleared the second on her lee bow. It is shown that by the bearing of Bonavista the next morning from the boat, the rock on which the Charlotte struck could not possibly be either in the place assigned to it, by ber commander, or our correspondents; and it is shown that the most probable place of the Bonetta rock is the Hartwell reef. Such are our conclusions, and when we see that the current has not been considered, either by the commander of the Charlotte, or the gentlemen who have so considerately worked her days' works; we do not see how it is possible to arrive at any other. While we are rejecting the position which the Charlotte places it in, we do not for a moment doubt the veracity of her commander. We are satisfied that he believed his reckoning to be perfectly correct; he gave the position of the rock, as he had found it; and we are no less satisfied, that, striking suddenly on the reef at the distance of four miles nearly off land, in the dusk of the evening, the island might not be seen through the mist occasioned by the surf, and the confusion which would ensue. The distance from the island the next day, which might have been determined by an angle of elevation of the land, would, as we have before observed, determine the question. But such as it is in its present state we leave it, fully persuaded that, under all the circumstances we have stated, and the deep water soundings which the chart presents in further support of our views, the Bonetta rock is no more than a part of the Hartwell reef. But whether it is or is not, sufficient reason will have been adduced to caution vessels to make a good allowance for the effects of a current in passing to wind ward of the Cape Verde Islands, without passing to the westward of them, as recommended by the American Consul, to avoid “the outlying reefs of Bonavista."

There are one or two points yet which have arisen in this discussion, on which we may say a word before parting with it. The Hartwell reef has been before us, and it would be interesting to know where the Hartwell considered herself to be by her reckoning when she struck. Her log, we presume, is preserved in the India house, as she is said to have been an East Indiaman, and baving treasure on board.

Another remark we would add is, that all the positions assigned to the Bonetta Rock, are comprised within seventeen miles of latitude, but range through nearly a degree of longitude, and all to the northward and eastward of Bonavista,-shewing a far greater westerly set than a southerly one, and agreeing with the conclusions of Major Rennell.

« 이전계속 »