the camel load, and, with the necessary stoppages, occupies two

The transport of the same merchandise from Lobeidh to Souaken only costs at most 128 piasters per rahal, and only occupies from thirty to thirty-five days, namely,

Thus the merchant who, instead of taking his gum to Cairo, transports it to Souaken, would economise greatly, and during the latter part of the dry season, the period when the gum is collected, he would be able to make two voyages for gum instead of one. From Khartoum to Cairo there are two routes, namely;

The first route, for different reasons, is seldom followed. From Khartoum to Souaken, however, the carriage of a rahal only costs from 64 to 68 piasters, and the voyage occupies twenty or twentytwo days.

From this it appears to me that if the canal between the two seas were open to navigation the whole trade of the Egyptian Soudan would pass through Souaken, and the greater part of this trade would pass through the canal.

I think I have shown that the canal between the two seas would open important markets in the Red Sea to European commerce, and render us masters of the interior of this sea. Thus Europe would behold her commerce and power increase, while countries and people long forgotten would see the barrier melt away which has so long separated them from us.

We have only considered, and that very slightly, the smallest portion of this vast revolution. What would be the result if we were to examine all its consequences? When the canal between the two seas

is opened, we may with truth say of Europe

"All thine shall be the subject main,

And every shore it circles thine."

Or, again, with the Portuguese poet who was one of the first to sail to India, "The whole of the ocean shall be subject to Europe,"

"Ser lhe na todo o oceano obediente."

And "The Europeans soon becoming masters of the world, will diffuse better laws,"

Rock Ferry, 21st June, 1856. Sir,-My allusion, in your last number of the Nautical, to the electric agencies which constitute, in an iron ship, a species of evervarying galvanic arrangement, together with the remark that we must look to the chemist for aid in seeking a remedy for compass vacillations, has doubtless raised in the minds of many of your readers suspicions as to the capability of such remedies (if found) being available by men. who are not, as a body, specially prepared either by education or abundant leisure for delicate scientific manipulation. I beg to acquaint you, that experiments, since my last letter, leave no doubt on my mind of the possibility of so nearly insulating a ship's compass, as to render any amount of local attraction imperceptible on the compass

card.

From the few words I addressed you, (marked "confidential,") hinting vaguely at the means employed, you will not, I am sure, accuse me of speculative puerility in my belief in this insulation; and as I before promised I shall be happy in a future number of this Magazine to lay before the public the nature of my recent experiments, with NO. 7.-VOL. XXV.

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their results, in order that abler hands may pursue the all-important subject with better facilities, if such be desirable; but I must record a belief, that the delicacy and cost of an instrument, which would be necessary to render a compass-needle self-correcting (as I was about to propose,) and the increased scientific attainment which seamen would require to render its use infallibly effective, would rather be altering the nature of existing difficulties than evading them. I speak thus candidly and without hesitation from the only hope to render, in my humble way, some permanent help to the compass question. We have, as an illustration, the Dipping Needle, an instrument of such capabilities and so useful, when it can be used, that no one would dispute its value, in such case, to a commander of a ship; but, unfortunately, here again its delicacy is such that on ship board it is a failure. Precisely so, I fear, would be my expected Insulator, and from like cause. But, sir, I should not have felt justified in raising hopes of effective remedy if I had not had a second string to my bow: like second thoughts second strings often do the most work, and I trust to show that in this case failure with the first establishes, by this very failure, the importance of its successor.

It

So much of late years has been said and written on the Mariner's Compass, that many are bewildered and disheartened; and it is evident that this feeling would be increased were I to stop here (if it be possible that my very feeble attempts could have much influence). is, however, highly pleasant to be able to offer at once to your nautical readers something more substantial than a description of a cruise in the wake of an ignis fatuus,-assuming and declaring (fortunately for my credit sake, that on very near approach it bore no resemblance to any of the wildgoose species,-as I am prepared in due time to show. On concluding the above chace, I found leisure to breathe and survey more clearly, from the higher land which I had ascended, the exact present position of what is so widely known as the Compass Question: and in this letter, after briefly showing what it really is, I would define what we really want; and propose what I declare to be a thorough and perfect remedy.

1st. This really is the compass question :

Captains of iron ships and of many steamers complain that they cannot depend on their compasses. These compasses, before the ship sails, undergo the best correction that the present state of science, and in the hands, too, of competent men, can devise. Boards and committees of distinguished men are selected and formed, private subscriptions, assisted by the Board of Trade, provide the means, and the energy and direct interest of even the Compass Committee themselves are, together with those of the whole naval and mercantile world, involved in the search of further help. As a proof of the intensity of their zeal, costly fittings are adopted, whereby to lesson, if possible, the evils of local attraction, and, it cannot be denied, that very often these evils are greatly diminished; but there is so little chance of permanence in the efficacy of any present mode of correction, that a venerable and most experienced gentleman (all honour to him!) has

even gone to the antipodes in an iron steamer in order to make further research! And this principally because it is often found, to the dismay of the mariner, that local changes in a ship's position, such as change of hemisphere, immensely affect, even to annihilation, the most careful corrections made at a distance.

The last phase which the compass question has undergone, does infinite credit not only to the promptitude but to the judgment of the Liverpool Committee: they have adopted the valuable suggestion of Sir John Ross, made several years since, and afterwards by Mr. Burdwood, R.N., in 1846, in the pages of your Magazine, and as recommended in principle by my unworthy self in my published address to the Liverpool shipowners in 1852. They have caused to be painted within these few days, in large and conspicuous figures, on the walls of the Liverpool Docks, the compass bearings, in degrees, of a tall prominent chimney, as coinciding with these points, thus enabling a vessel, when at anchor, or as she leaves the Mersey, to correct her compasses by mere comparison with these marks. It is admirably done, and worthy of imitation at other ports, and I hope soon to hear of its adoption at all the principal headlands in the British dominions. But imagine the whole coast of Europe, Asia, Africa, America, and Australia, to be painted thus! Would this prove a perfect remedy? Certainly not, far from it! As an instance,- -a few days since, in speaking to a captain of an iron steamer just arrived from foreign service, who appeared still weary and hoarse from two or three nights' exposure on deck, and in only moderate but thickish weather in the channel, his reply to my friendly question, "But could you not get at least some rest on these occasions?" was simply this,-" Yes, but I am always afraid to trust my compasses, and we could not see the land."

Now, sir, devoted as your Magazine has always been to the best interests of naval and mercantile captains and officers, surely I may be borne with while remarking on this state of things. Why, the hard earned reputation of a captain of forty years' experience, who never before damaged a sheet of copper from touching terra firma, hangs by a thread, because he can depend so little on his compass! The office of commander of a merchant vessel, is one of immense responsibility, care, and peculiar hardship. I should be ashamed to draw such a conclusion from the circumstance of two or three nights' exposure. Nor would they sanction its mention it is their avocation, their lot! and for ages endurance has been the proverbial character of British Seamen, nor have, as all the world know, either sailors or soldiers degenerated. But is it not adding needlessly to the cares of a most honourable and distinguished class of our fellow men, when we permit the slightest hope of amelioration of those evils which press on them through the compass question to go unheeded? For it must be borne in mind, that since the supervision of the Board of Trade adds to the security of commerce, it is at the cost of great personal privation, and increase of danger to the reputations of merchant captains,— through the errors which affect the best regulated compass. Where

no indication on land, like those on the Mersey, are visible, I would ask.

Secondly, What we really want?

A sailor only wants to know what course to steer by his ship's compass to bring him by the shortest route to his destination. But in the absence of all honest guides, (as his compass deceives him,) it appears to me that at sea, in order to render the compass reliable, there can be but two kinds of remedy or correction: the one would be a perfect or sufficiently approximate insulation of the compass-needle from all but terrestrial magnetism; (and this I have now no hope of ever seeing;) the other would be by instrumental correction. As regards the latter, my object is not to deny any man's attempt, much less would I wish to disparage such corrections as, in the absence of better, have been sanctioned by so high an authority as the Astronomer Royal; but it appears that all corrections by instrument or apparatus may be separated into two classes; namely, the one dependent on magnetism or some modification of it; (but which Compass Committees pronounce to be inadequate ;) the other depending on the help of the quadrant or sextant, as used with the heavenly bodies. And here again we are met with hitherto insurmountable difficulties in actual practice. What we really want, then, is (no matter from what source) to be able readily to ascertain the true direction of the cardinal points of the compass; and by a method which requires little or no calculation, available at most times of the day or night, either at sea or near a coast, a method clear and positively efficacious, always to be confidently relied upon. In considering, therefore,

Thirdly, A thorough and perfect remedy,

I beg leave respectfully to acquaint you, that after much labour I have succeeded in producing an infallible correction of the following general nature; namely, I thus publicly undertake to suspend, in a captain's state room, or to attach to his timepiece, a very sightable and in many of its other applications a highly useful and instructive instrument, (very cheap, even to a few shillings, or expensive, according to the will and means of the possessor,) which will, without reference to books, (or more knowledge than the captain of a ship carries in his head at present,) and by means of a slight mechanical movement, aided by a second act equally simple, which will, I say, give such captain his true compass error. He may keep this instrument in his writingdesk, or even in his waistcoat pocket. I speak deliberately when I assure you that it is so ridiculously simple, (alas! parturiunt montes nascetur ridiculus mus,) so perfectly unpretending is this instrument, that sailors, with all their professional gravity, must laugh at it;-I only hope it may not from its simplicity be underrated. In itself, as an arrangement, it is so comprehensible, that any master of a vessel of common intelligence, will on once seeing it used clearly comprehend it. I furthermore see no reason why the compass error should not henceforth be entered in the log every watch when practicable.

In apologising for a somewhat enigmatical and apparently selfish style of introduction, I beg to explain that, apart from pecuniary con