History of the Atlantic Cable & Undersea Communications
Deep-Sea Telegraphs (1861)
THEIR PAST HISTORY
A SERIES OF ARTICLES RECENTLY PUBLISHED IN THE “MECHANICS’
Price One Shilling.
DEEP- SEA TELEGRAPHS:
THEIR PAST HISTORY AND FUTURE PROGRESS.
THE history of submarine telegraphy—fairly written—would reflect little credit, either scientifically or morally, upon the present age. In truth, the business of making and laying telegraphic cables is—after a lapse of ten years since their introduction—only now commencing to be treated with the dignity of a science. Great and useful principles have been elicited by repeated failure, but they have been mostly ignored in practice. Experience there has been, but its lessons have too often been disregarded and thrust aside. Discussion there has been in abundance, but its tone has been too much for the display of theoretical learning to contribute to any valuable result, and far more apologetic in behalf of error than solicitous for truth—the grain of scientific wheat being usually hidden in a measure of algebraical chaff and mystification, as if to create and keep up a sort of telegraphical hierarchy, unapproachable except by the initiated. This latter mode of treating the question is especially the most dangerous and unnecessary that could be adopted, except for the purpose of speculative philosophy; as the successful construction of the telegraph is no mystery to any mind of fair capacity; depending as it does simply upon the practical application of a very few easy and perfectly well-known natural laws.
Nor have the moral aspects of submarine telegraphy been hitherto much more encouraging, the inception of these undertakings being generally on this wise.—A gentleman with a genius for negotiation and a laudable desire to relieve his normal impecuniosity, starts on a foreign expedition, and, by dint of introductions, intrigues, and promises of favour, he succeeds in obtaining a concession of the monopoly of laying cables in a particular district. Armed with this document, he returns to his native land, whose pockets (not forgetful of his own) he designs to fill with the fruits of his disinterested labours, and, unless ambitious of uniting in his own person the functions and rewards of projector, engineer, and contractor, he usually betakes himself to such gentlemen of those latter professions as he may deem to be desirable connections either on account of their influence in particular quarters or their skill in working these matters with the public or the government.
Preliminaries being thus settled, the confederacy proceed to decide upon the capital that shall (or can) be raised for the enterprise. The next step is to settle the remuneration to be absorbed out of that fund by themselves in cash and profits; and, that important question being agreed on, they, last of all, proceed to ascertain how far the balance will go towards constructing and laying the required cable, the form and substance of which is thus arranged among themselves on a principle which is, in fact, pecuniary; and, if accidentally scientific, so much the better.
Usually, as might be expected, the conductor is starved,—the insulation is starved,—and all the belongings of the cable are attenuated, except the profits of the contractors and the concessionaire, which latter having been the primal and leading objects of the scheme, it can hardly be said to “fail” under any circumstances, when once the capital has been secured. If the cable happens to go down to the bottom all right, it is good! Spirited projector! Talented engineer! Eminent contractor! If it fails, it was the copper, or the gutta percha, or the ship, or a submarine volcano! anything, of course, except the fault of the eminent personages engaged in the work.
Meanwhile the shareholders’ money is all gone, science is retarded, Mammon triumphs, and
Under such empirical treatment the whole question of ocean telegraphy has pretty nearly come to a dead lock; and it is only by carefully retracing our steps, by narrowly watching the initiation and original constitution of these undertakings, and by taking care that their scientific principles and business arrangements are settled on a sound and honourable basis, that the submarine telegraph can be made in future a safe and permanent institution.
Matters have indeed arrived at a climax when—the supplies being cut off—there is nothing for it but repentance and amendment; and when renewed confidence can only be secured by a code of morals, and a plan of operations, in accordance with reason and good sense.
The belief, even, in the ultimate practicability of deep-sea telegraphs has been deadened, if not destroyed, in the minds of thousands whose faith in them was at one time enthusiastic. Even those whose business pursuits would be greatly benefited and facilitated by the establishment of this rapid means of communication, and who on that account would readily provide the money for its establishment, under a reasonable prospect of success and permanence, have at present lost all sympathy in the matter, from witnessing until quite recently a recurrence, so constant, of disappointment and loss.
It is evident, then, that this feeling must undergo considerable change before much progress can be made; and, as it has very much arisen out of the want of credible information, and the gloss usually thrown over these undertakings, whereby the whole truth regarding them is kept in the background, it is desirable, not merely to indicate the teachings of experience as to the material means whereby success can be achieved, but also to endeavour, by recalling to memory, the salient points in some of the principal failures, to show how little of a really scientific character there has been to oppose the perfect establishment of the ocean telegraph, and how completely past efforts have been marred by causes which ought never to have existed, and would never have been heard of, but for the reckless manner in which these projects have been initiated and carried forward.
The magnitude of the loss thus occasioned by controllable causes may be judged of when we state that, out of more than 12,300 miles of deep-sea cable that have been made and laid or attempted to be laid (being somewhat more than is accounted for in the Board of Trade Report) less than 3,000 miles are actually at work. It is well, however, to state that the Atlantic and Red Sea cables form more than one half of the 12,300 miles. It is not a little remarkable also that out of the total of 9,000 miles of cable that have been lost more than 7,000 miles were manufactured by one firm alone; and it is the fact, that not an instance has occurred of any failure owing to the decay or decomposition of gutta percha, which, up to this time, has been the sole material employed for insulating submarine electrical conductors.
This latter circumstance is highly important—and being grounded upon ten years of actual experience is eminently re-assuring—having regard to the ultimate commercial success of these investments, inasmuch as the fact is thereby demonstrated that complete and indestructible insulation—the most vital of all considerations in a submarine cable—is at least a matter easy and certain of attainment.
THE RED SEA AND ATLANTIC PROTECTS.
THE various Blue Books that have been issued on the subject of Telegraphic Contracts, and especially the recent elaborate report of the Committee appointed by the Board of Trade to inquire into the construction of Submarine Telegraphs, provide abundant elements, in connection with other published documents, for raising the true issue in respect to this great question. We believe it can be shown that in every instance, where there has been a want of success, it is fairly attributable to circumstances which can be readily avoided in future, and which may be proximately comprehended in the following category:—1st. The traffic in concessions and monopolies.—2nd. The contests of rival contractors.—3rd. The false economy displayed in regulating the size of the conductor, and the quantity of insulation.—4th. The inadequacy of the tests applied during manufacture.—5th. The inordinate and unnecessary haste which has prevailed in the manufacture of cables.—6th. The absence of any useful or properly-conducted practical experiments with various and differently-constituted cables, so as to determine from facts the form and specific gravity most suitable for deep water.—7th. The insufficient soundings and imperfect examination of the route to be traversed.—8th. The inconsiderate and unskilful manner in which the specifications and contracts have been drawn, whereby, in some instances, an actual premium has been offered to cupidity and extortion; and, finally, we may not omit a cause of injury to submarine telegraph property, which, in common charity, we would fain disbelieve in, were it possible. It is, however, too true that malicious damage has, in more than one instance, been the ruin, partial or otherwise, of electric cables.
In enumerating avoidable sources of mischief, it would be ungenerous to those individuals who have laboured with ardour and bona fides upon a work so new and originally so untried as that of submarine telegraphy, were we to omit to say that some consideration and forbearance is due in respect to that proportion of error which is, of course, natural and incident to novelty, and to the consequent absence of experience. Great credit is due to many of these gentlemen; and whenever they have been allowed fair play and due influence, a corresponding success has usually been the result. Had these been the men chiefly consulted—had they been permitted to exercise a proper degree of control, and had their experience been allowed to bear its legitimate fruit, there would now be little to complain of, and the mind could at once address itself to the improvement of such lessons of the past as are exclusively scientific, without the necessity for first clearing the ground of their far more injurious though artificial obstructions and prejudices arising out of the blunders and excuses of mere charlatanism and cupidity, which have defaced these national undertakings.
This, unfortunately, is not the case; and it therefore becomes necessary, in order to understand why so many submarine telegraphs have failed, to enter somewhat in detail into the moral as well as the scientific history of some of the more important failures.
Let us, therefore, without regarding the order of date, select, in the first instance, one of the most gigantic and illustrative of these disasters, premising that its history chiefly differs from that of some other similarly constituted schemes in the magnitude of the loss sustained, and in the degree of notoriety thereby achieved. We allude to the Red Sea Company’s undertaking, and its connections in the Mediterranean.
So far back as 1855, Mr. Lionel Gisborne, and Messrs. Newall and Company, had jointly obtained a concession for establishing a submarine telegraph between the Dardanelles and Alexandria, with a monopoly of communication for fifty years. By a subsequent concession, Mr. Gisborne, as trustee for the same parties, was authorised to establish a submarine telegraph along the Red Sea, on condition that the Dardanelles line was completed by December, 1858.
There were, however, other competing projects, one of which was being worked by Mr. J.W. Brett, who was endeavouring to induce the Austrian Government to contract with him to lay a telegraphic line between Ragusa and Alexandria. Another scheme was favoured by the Indian Government, and recommended by Sir W. O’Shaughnessy. This latter was intended to commence at Constantinople, and to terminate at Kurrachee, by way of Bossorah and the Persian Gulf. For a third project, proposing to reach India by a land line along the valley of the Euphrates to the head of the Persian Gulf, and thence by a submarine cable to Kurrachee, a company was actually formed, and, at one time, they were in expectation of receiving a conditional guarantee upon their capital; but these were superseded, owing, in a measure, to the superior influence of the persons interested in the Red Sea scheme.
Not being able, under these circumstances, to carry out the Dardanelles concession by means of a company, within such a period as to secure the Red Sea monopoly, Mr. Gisborne sold it to Messrs. Newall, who undertook to lay the cable, at their own cost, by the time stipulated. This they attempted to do, with a cheap and ill-constructed cable, but failed, by its breaking, after the paying-out ship had hung on to it for thirty-six hours, in heavy weather. The Ottoman Government were, however, induced, in 1859, to renew the concession, granting Messrs. Newall £4,500 a-year on completion of the Dardanelles line, and containing the following extraordinary clause:—
It will be seen that the effect of this clause was to place the Red Sea project entirely at the mercy of Messrs. Newall, and to frustrate the desire so earnestly expressed in this country for direct and independent lines to connect our fortresses of Gibraltar and Malta with the south-west of England on the one side, and with the north coast of Egypt on the other, so as to form a continuous and national route to Alexandria, and onward to India. Every message would have had to pass over Messrs. Newall’s lines, and the monopoly would of course have been of enormous value. We shall see presently how it operated upon the interests of the Red Sea Company. Meanwhile, the English Government on the one hand were earnestly endeavouring to induce the Ottoman Government to cancel this arrangement, while Messrs. Newall on their part were doing their utmost to render it irrevocable by submerging in hot haste a cable of some kind between Constantinople and Alexandria, so as to complete and finally close their concession. The first attempt having been made with a hempen cable, of which a considerable balance remained on hand after the failure, they surrounded this with iron, but only very scantily, so that, in fact, the hemp was visible beneath it. Nevertheless, this cable, though never properly tested, so thinly insulated with gutta percha, and so imperfectly protected externally, would in all probability have succeeded for a time, had the appliances for paying out been well managed. As it was, however, the cable was jammed and broken. Messrs. Newall then borrowed some of the Red Sea cable (at that time in course of manufacture), for the purpose of carrying out their concession; but here a false economy proved again disastrous. Instead of using new cable for the entire distance, (420 miles), as they might have done, they borrowed 315 miles only of the sound, new, Red Sea cable. This they paid out successfully, and then tacked on to it the old iron-covered cable which had originally been part of failure No. 1; but when they had paid out 25 miles of the latter they were obliged to stop, and in attempting to haul it back they broke it, and lost the whole. To comment upon such reckless management is needless.
While all the matters just related had been progressing, the Red Sea Company had been formed, with £800,000 subscribed capital, upon which had been obtained a guarantee from the British Government of 4½ per cent., not conditional upon success, and we shall now see the force and bearing, in another direction, of the exclusive clause in the Dardanelles concession, which turns out a means of fixing, without competition, the appointments of engineer and contractor to the Red Sea Company, and thus forms a convenient “hedge,” at the expense of the English Government and the public, against the risks and losses of the Ottoman line. How all this was done is so well described in a letter, addressed by Glass, Elliot and Company, to the Lords of the Treasury, on 26th June, 1858, that we give that letter, which has never been contradicted, exactly as we find it in the Blue Book. Messrs. Glass’s letter is as follows:—
Now, the foregoing is, of course, open to the remark that it shows the subject from one point of view only; but it has been published in a Blue Book, read by the president of the Institution of Civil Engineers at a crowded meeting of that body, and has never been contradicted or impugned.
With the contests of rival contractors we have neither sympathy nor concern; but if the general facts are as stated in the letter just quoted, they bear strongly upon the public question we are now discussing, and we are bound to say that any enterprise so constituted gives very little hope of success.
But the sequel was still worse. The cable selected for submersion in the Red Sea, though possibly under better auspices it might have been laid with success (for cables, in general, though much maligned, have, in truth, shown great powers of endurance, considering the treatment they have received,) was not brought under discussion or submitted for approval to any of those who were best able to judge of its suitability—neither conductor nor insulation being founded upon any experience, but decided on with reference to considerations mainly apart from science. This was the more culpable as the Red Sea Company had ample time to have profited by the experience derived from the great experiment of the Atlantic Cable, in arranging the electrical constitution of their own line. Instead of doing so, the Red Sea Cable, at a greater cost per mile, was actually inferior to that of the Atlantic Company.
The terms of the contract entered into with Newall and Co. were equally fraught with danger, and there can be no doubt they were the proximate cause of the failure.
It was provided in one clause that the cable was to be laid between Suez and Kurrachee, and delivered over in good working order, in condition to transmit ten words per minute; but in clause 5 of the same document this stipulation, which would have been of some use, is annulled practically, for the cable being intended to be laid in sections, it is there provided that “no part of the money is to be considered due until the cable for each section shall have been at work efficiently, as hereinbefore specified, for one clear calendar month,” &c.
Now it has been denied, almost without contradiction, that any message ever passed from end to end of the Red Sea cable; but certainly the whole cable was never at work for anything like the period of a month.
The contractors, however, relying upon the ambiguity of the contract, insisted upon payment for each section separately, although they, one after another, broke down, before the completion of the whole. At first, indeed, there was some show of resistance to this, and it was thought, at one time, that a legal contest was imminent. It seems, however, that the whole story would have been too good for the public ear, and the affair was compromised—the country being thus saddled with a payment to the Red Sea shareholders of nearly £36,000 per annum—without any consideration in return—a result for which there was not a shadow of necessity if the business had been conducted in the spirit of good sense and good faith.
But finally, the point in this contract which in all probability proved to be the most fatal now deserves attention. The contractors were not bound to furnish and lay more than a given length of cable (calculated to leave about 20 per cent. for slack) for the very handsome lump sum which constituted their consideration; but it was provided that whatever they (the contractors) could save out of that length should become their own private property, forming an extra bonus upon their already large profit. Here was a direct premium offered for stretching the cable—especially as Newall and Co. were in the position of having to repay the 300 miles which they had borrowed for the purpose of establishing telegraphic communication between Alexandria and Constantinople.
The consequences of such arrangements are in evidence. It is stated that in many places the cable is laid as taut as a harp-string, and that when attempts were made to repair the faults—several of which were, in all human probability, produced by extreme tension—it was found impossible to raise it without fracture.
Much more might be said about the arrangements of this undertaking, but we think we have thus sufficiently shown that in this, the largest case of failure, the causes, immediate and proximate, are perfectly clear and quite capable of being avoided in future.
It only remains to be stated that the Alexandria and Constantinople line, which the directors of the Red Sea Company considered so important as to render it necessary for them to give their own contract to Newall and Co., without competition, in order to secure it, is to this day uncompleted—the absurd monopoly thereby created having been put an end to by the influence of her Majesty’s Government.
The Atlantic Telegraph is next among the failures in submarine telegraphy that offer material for instructive comment; and here, as in the foregoing case, we find the elements of future trouble in the very initiation of the undertaking.
So far back as 1854, seven citizens of New York, of whom the most active in the business was Mr. Cyrus W. Field, were enabled, by bringing powerful influence to bear upon the Newfoundland Legislature, to procure an Act, conferring upon them, on condition of their completing telegraphic communication between St. John’s and the United States, the following extraordinary privileges, namely, a guarantee of 6 per cent. upon £50,000 of bonds, the exclusive right, during 50 years, of landing cables upon the shores of Newfoundland and upon the Eastern shores of Labrador, as far as Ungava Bay; a grant of 50 square miles of land as a free gift upon completion of the lines in Newfoundland, and of another 50 square miles whenever, during the continuance of the grant, it should be found possible to lay a telegraph line between Newfoundland and Ireland.
Having secured these powers, they next sought, and were to a considerable extent successful in obtaining, similar exclusive rights of landing cables in Nova Scotia, New Brunswick, Cape Breton, Prince Edward’s Island, and the State of Maine; thus protecting at every possible opening the western terminus of the only route deemed to be practicable for connecting Europe with America, which latter was the ulterior object in procuring the Newfoundland concession.
With all these advantages, however, it was only found possible to carry out that portion of the scheme between St. John’s and the United States—public belief in ocean telegraphy being at that time very limited.
The Transatlantic portion of the undertaking was therefore cut off from the main project, and brought forward as a separate enterprise, and the funds for its execution not being forthcoming in the United States, Mr. Field opened a communication with Mr. J.W. Brett, of London, who was well known as a projector of submarine telegraphs.
It was arranged that all the exclusive privileges of the Newfoundland Company should be turned over to the future Atlantic Company, but not the grants of land nor the guarantee upon the bonds. Still there was little progress until 1856, in which year subsidies of £14,000 a-year from the United States Government, and of the same amount from the British Government, were simultaneously promised to Mr. Field and Mr. Brett.
A provisional committee was then formed in England, consisting of the projectors and others pecuniarily interested, and a number of experiments were tried to determine the possibility of working across a distance so great as the Atlantic Ocean, and to shew the best form of cable to be used for the purpose. So far good—but here the troubles of the undertaking commenced. The provisional committee were very soon at issue as to the description of cable to be used, and instead of boldly appealing, as they might have done, for aid and advice in so weighty a matter to the best and most practical engineers and electricians of the day, the whole issue was cramped and narrowed by considerations which ought to have had no weight, and the decision was pressed forward, especially by some of the projectors, with the most ill-advised precipitancy.
Their electrical adviser protested against the undue haste with which matters were progressing, and demanded time for further experiment, and this not being conceded him he should have refused to proceed; but, on the contrary, he was constrained after all to yield, against his convictions, to an electrical constitution of the cable in which he had only a very imperfect confidence. So the cable was at last decided on, and being a very pretty object to look at, it secured from the first a good deal of favour from persons unacquainted with science; indeed it has been stated, and we believe with truth, that its external appearance, and the apparent economy in the cost of it, weighed very strongly with the projectors, in deciding upon that part of the question against other and better descriptions of cable, and particularly against a less pretentious but far more suitable form of outside protection, constructed of steel wires covered with hemp, as suggested by Mr. Samuel Statham—the specific gravity of which would have been in accordance with the great depths of the Atlantic Ocean. Appearances and cheapness, however, carried the day; and the combined persuasions of the cable, of the exclusive privileges, of the subsidies, and of the projectors, were successful in procuring subscriptions for £350,000—a capital far too mall for so important a work.
The remuneration to the projectors was also settled by the provisional committee, and if they had then stopped all might have even yet been well. Had the questions influencing success been left at the point we have now arrived at, and emitted for further consideration and action to the men of business and mercantile standing, who were afterwards selected by the shareholders to form the working board, there was very possibility that much of the subsequent difficulty and precipitation might have been avoided, and many deficiencies corrected; hut this provisional committee, not satisfied with indicating, on insufficient experiment, the kind of cable they thought to be the right one, and ignoring the sound advice at was tendered to them by experienced telegraphers, as to the necessity for a larger conductor than the one adopted, actually proceeded to conclude and settle the contracts for its manufacture, without leaving the future board the least voice in the matter. Many of the experiments having been made by Messrs. Glass, Elliott, and Co., that firm had, from the first, been promised that they should be the manufacturers of his cable, and everything went on upon that understanding until the arrangements for the capital were completed. At this stage, however, the committee called in Messrs. Newall, and having submitted to them the samples prepared by Glass and Co., they consulted them as to their prices. These two firms were then, as they always have been, bitterly hostile to each other; and a great effort was made by Newall and Co. to get the contract away from Glass, notwithstanding that they strongly condemned the form of the cable. Thinking to adopt a middle policy, the committee gave half the contract to each, and the consequence was that the two halves of the cable were made by these two antagonistic parties—the one at Greenwich and the other at Birkenhead, and it was never possible to test the cable through from end to end until the ships were ready to sail from Queenstown in July, 1857, and even then very imperfectly. This was a fatal mistake, and not less fatal was the haste with which the materials of the cable were put together. The contractors were bound to deliver the whole cable on board in June, 1857, though it was not possible for them to commence their work till February of the same year; and it will give some idea of what this means, when we state that there were 2,500 miles of copper to be covered three times with gutta percha, and 332,000 miles of iron and copper wire to be drawn out and spun into nineteen strands of 2,500 miles each, besides the serving of hemp and tar, and the coiling of the completed cable on board the Niagara and the Agamemnon.
That some of this was put together most imperfectly, either at the manufacturers’ or on board ship, cannot be doubted, for there were recently exhibited at the Institution of Civil Engineers four or five joints in the copper wire which were stated to have been cut out of some of the recovered cable, any one of which would have led to certain failure, the copper being merely twisted together in a loose bunch, and surrounded by a solid lump of gutta percha. We are informed that none of these joints were discovered in that portion of the cable made by Glass and Company; but of course this does not prove that they were made by the other manufacturer, as their paternity cannot now be identified.
They must be sanguine men, however, who could hope for success under such circumstances. The board of directors was not chosen, as we have said, until the contracts had been disposed of and all they could do subsequently was to watch over the manufacture of the cable as well as they were able.
Even this they could only perform in a very imperfect and inefficient manner, owing to the confusion into which every thing had been thrown by the precipitate arrangements of their predecessors, and to the double relation in which, from the first, their chief scientific advisers stood towards the undertaking,—those gentlemen being, not only officers of the Company, but projectors and concessioners also.
The contract for the cable being in the hands of two separate contractors, and the time for its completion being so limited, it was impossible to test it under water, except in its uncovered state at the Gutta Percha Works, or to work through its entire length experimentally. In justice to every one, it ought also to be remarked, that every thing was at the time so new in respect to deep-sea cables, that the necessity for the test under water was not then deemed so essential a process as it has been shewn to be by subsequent experience.
Testing under pressure, too, had not been thought of, and, if known, there would not have been time to make the necessary arrangements for its application. The galvanometers then in use for testing cables electrically were, moreover, totally different and inferior to those now in use, and the plan of testing by units of resistance had never been applied. The phenomena of long deep-sea cables were at that time novel and obscure, and the instruments applied to the Atlantic core were, at any rate, much in advance of any that had preceded them; indeed, the insulation tests that had previously been thought sufficient and even admirable for shallow water cables and short lengths were such as would now be rejected by experienced electricians for the most inconsiderable lines.
Being duly completed at the stipulated time, the cable went to sea in August, 1857, and the inefficiency of the paying-out machinery then became at once manifest. This was a ponderous and complicated series of iron wheels, geared together, and regulated by friction breaks of lignum vitae, the lubrication of which was difficult and imperfect, and, being left in charge of a working man, too much pressure was applied, and the cable snapped 380 miles from Valentia. It is satisfactory to note, however, that the deep water offered no obstacle to the submergence of the cable with perfect safety; the signals were reported good to the last, and the sudden transition from 500 to 1,700 fathoms, in eight miles, had been long passed with facility. Then came the return to Plymouth, the uncoiling and packing away of the cable for the winter, its subsequent recoiling into the ships, and all the usage to which it was submitted in 1858, from the fearful storms in the Atlantic, and three preliminary trials in that year preceding the final success. We cannot but wonder that it was ever possible, under all the complications of unfavourable circumstances which we have endeavoured to sketch, that one word or one electrical signal should have ever passed through it; not to speak of the 300 messages which the directors have certified to have been conveyed by it between Ireland and Newfoundland.
The speed at which these messages could be sent through the Atlantic cable was certainly slow, having been at the rate of only two and-a-half words per minute, but even this low speed would have produced a large commercial profit to the shareholders, and the experience of the conductor now being laid by Glass, Elliot and Co., from Malta to Alexandria, shows that to be a fact of which the projectors of the Atlantic Company were early warned by practical telegraphers that distance offers no difficulty of any great moment to the transmission of electric force, provided that the size of the conducting medium be increased in a moderate ascertained ratio to meet its increased extension.
THE MEDITERRANEAN PROJECTS AND SINGAPORE AND BATAVIA CABLE.
WE have thus endeavoured to set forth a few salient points in the failures of submarine telegraphy, in the Red Sea, the Atlantic Ocean, and the Levant; and in each case the facts are highly favorable to the belief that the final catastrophe might have been easily avoided under judicious management and by ordinary skill. In further illustration of this view of the subject, and in order to show that the same disregard of common prudence has characterized both great and small of these undertakings, we now proceed to comment upon some of the chief among the remaining enterprises whose untoward and unnecessary fate has done so much to retard the progress of communication throughout the world.
And first let us consider the lines of the Mediterranean Company, being from Spezzia to Corsica, Corsica to Sardinia, and Sardinia to Africa. It is but right to say that over the two first sections of this route the cables, though weighing eight tons per mile, were well made, well laid, and (consequently) have worked well ever since, and have not cost a shilling in repairs; but the African section is to this day unfinished, though three attempts have been made to complete it. On the first occasion, in 1855, the gerant and projector, Mr. J.W. Brett, went to sea with the cable, which was a good one, about eight tons per mile; but in order to save expense, the paying-out machinery was taken on board in sections, which were not put together until he arrived at the spot for commencing operations, and there were no means, therefore, of testing in any way its suitability. Moreover, though warned by a temporary accident, which had taken place in 600-fathom water, even between Spezzia and Corsica, the cable was only passed three times round each drum, and the consequence was that they had hardly started two hours before they were obliged to stop on account of the cable having too much play. On the second day’s work it ran out with such velocity as to be uncontrollable, and at last it tore up some of the heavy shoring planks, and flung them on the deck, and having then been tested, it was found to be electrically bad, and it was decided to cut it and begin again. They accordingly went back and began again. But it never occurred to them to make any proper calculation of the distance to be run, and the consequence was that when they had laid down about 60 miles without any means of comparing the rate of emission of the cable with that of the ship’s progress, they found by nautical observation that the distance yet to be run left them no hope of covering it with the cable at their disposal, and they therefore cut it in calm weather, abandoning the portion laid, in order to save the rest, and came home again. It should be stated as a further proof of imprudence, that this eight-ton cable was attempted to be paid out of a sailing vessel—towed by a little French coasting steamer, the Tartare, which of itself was unable to make five knots an hour. The projectors, however, did not despair. They determined to sell, if possible, the remainder of the heavy cable, and attempt to lay a line of a different character. But by this time the funds were getting low, and on this second occasion they were compelled—to use Mr. Brett’s own expression—“to cut their coat according to the cloth.” An evil maxim this in submarine telegraphy! the principles of which demand imperiously that there shall be no coat at all, if the exchequer will not pay for a good one. However, it has been admitted by Mr. Brett that, instead of being a cable upon which any hope of success could be founded, it was starved in every particular—in the conductors—in the insulation—in the external coverings. It weighed about four tons to the mile. It was taken out in the Dutchman steamer; and—will it be believed’? the persons in charge—unmindful of the two previous accidents in deep water by the cable running away from the ship—actually again committed the same error which had led to that result. They again only laid three turns round the drums, and again the same thing happened as on the former occasions—the cable surged and ran away, and in stopping it, it was jammed and broken. They went back, underran the sunken cable, and spliced it to that in the ship; and having this time taken five instead of three turns round the drums, all went well, and they laid this heavy cable perfectly in depths of 1,600 fathoms; but foresight seems to have been a quality quite absent from the managers of this expedition. After the greater part of the cable had been submerged, they found that on this, as well as on the last occasion, false economy was about to ruin the enterprise. There was not sufficient cable! They then thought if it would not reach Bona it might reach the island of Galita; but in this also they were mistaken, having drifted, for want of proper nautical skill, upwards of 13 miles out of their course. They paid out as far as they could, however; and being still 13 miles from Galita, they telegraphed through the wires to London for an additional supply of cable, and having lashed to the ship the end of that which remained, they dispatched a vessel to Algiers for other help. For five days and nights—in 500-fathom water—this cable held on, and remained perfect; but a storm arose, and after 48 hours’ pitching and rolling of the ship, in a heavy sea, it parted, and thus ended the second of these cables.
The projectors next determined, so soon as they were again in possession of pecuniary means, to turn over the whole business of making and laying the cable to a contractor; and they accordingly arranged with Mr. Newall that he should make, and lay, and deliver over in perfect order, a 4-wire cable, weighing about 3 tons to the mile, for the lump sum of £50,000.
When it was completed, Mr. Brett, on examining into the quantity provided for shipment, found that, in addition to the innate poverty of the cable as a cable, his own error of false economy was about to be again repeated, in respect to quantity also. He remonstrated in vain, and it turned out as he had foretold. They were again 12 miles short of cable! They managed to patch a piece on to make up the distance, after considerable delay, but the cable never worked properly, except in one wire; and is now not only useless, but the subject of a lawsuit in the French courts. Besides this, the cable is a miserably starved production, which, even under favourable circumstances, could have had but little prospect of permanent success. The agents of Mr. Brett were prohibited by the contractors from testing it with a negative current, and it is in evidence in the French proceedings that, in order to be enabled even to fulfil the letter of the contract—which provided that the cable should work during eight days—the agents of Messrs. Newall found it necessary to keep a positive current of electricity passing through it day and night, from 130 cells of Daniell’s battery, frequently renewed; so as to stop up thereby, for the time being, by conversion of the copper into oxyde (a non-conducting substance), the fissures and defects that existed in the insulation. Some of these fissures have since been taken up, and discovered to be maliciously effected; and it is stated in the French proceedings that they consist of long gashes in the gutta percha, artistically made, and partially closed again, so that the death of the cable might not be effected too suddenly. Unfortunately, the guilty persons have hitherto escaped, though we believe a clue exists whereby it is hoped they may yet be discovered.
Let us now glance at the proceedings in respect to the Mediterranean extension cable—a line of 700 miles from Cagliari to Malta, and thence to Corfu. The company had a capital of £120,000, and a conditional guarantee of 6 per cent. upon it from the British Government; and what did the directors do with it? Instead of looking into the matter with common sense, as merchants and men of business—calling around them the best advisers, and examining for themselves the description of cable to be used—they practically turn over their functions and nearly all their money to a contractor; and, forsooth, because he agrees to make and lay their cable so that it shall succeed for a week or so, they allow him to dictate its form and electrical qualifications, and leave him free from everything but the obligation of working through it during the short time agreed on. In such a contract there is manifestly the strongest inducement to make a cable that shall be the easiest to lay, without. reference to permanence or durability, with which the contractor has nothing to do.
This Cagliari to Corfu telegraph, therefore, as every experienced person must have well known, and as many had foretold, had no one element of success about it; although the money allotted to its construction was sufficient to have secured under better management a far different result. It might be a very good cable to lay, but being notoriously attenuated and imperfect in every other respect, it had not the least chance of permanence upon the jagged and imperfectly surveyed bed of the Mediterranean—laid, as it was, with very little regard to slack, and being, like the bumpkin’s razors, chiefly made to “sell.” After working, therefore, during a brief period, both sections failed, and after some badly managed and inefficient attempts to repair it, the entire property was abandoned.
On this part of our subject we have only now to allude to the Singapore and Batavia cable, which is another instance of total misapplication of means to ends, an absurd and misplaced economy being in this, as in several other cases, the proximate cause of disappointment. The route along which it is laid scarcely permits of its classification among deep-sea cables, as it is supposed to be for the most part very shallow, though possibly there may be sudden variations, as in this case, like many others, there was never—what is so much needed in all instances—a careful examination of the bottom along which the cable was to repose.
However, the route being for the most part, at all events, of no very serious depth—admitting, and indeed requiring, the strongest form of cable, the Dutch Government were induced to contract for a deep sea cable almost identical with that selected with equal imprudence for the Red Sea, having a very inferior constitution both internally and externally, the result in a great measure of the intrigues which preceded the allotment of the contract. Hence, after having been injured by anchors and repaired again on one or two occasions, it has at last been carried away altogether, and so far without hope of recovery.
We have thus disposed of more than 8,000 out of the 9,000 miles of deep-sea cable failures; and it can hardly fail to have occurred to a candid enquirer, that success ought not to have been expected, even to the extent to which it was obtained in any one of these instances; nay more, it would flow naturally from the considerations to which the recitals of these disasters give rise, that if even a temporary triumph can be achieved under such disastrous circumstances, it must be clear that, with proper business arrangements, the art of making and laying deep-sea cables can be brought to as great certainty and perfection as any other mechanical operation.
We now desire to draw, so far as may be, from the records of experience for information as to the material means whereby this happy consummation is likely to be to some extent assisted and facilitated.
THE FUTURE OF DEEP-SEA TELEGRAPHY.
PROJECTORS’ INTERESTS—NECESSITY FOR SOUNDINGS—SIZE AND
THE preceding observations have been directed to the setting forth of such facts as prove that the success of deep-sea cables has hitherto not been impeded to any extent worthy of mention by natural or scientific obstacles, but chiefly by reckless, blundering, and selfish mismanagement.
It now remains to discuss by the light of past experience, the leading conditions hereafter necessary to the safe and permanent accomplishment of these undertakings, and,
First, the manner in which projectors, concessioners, and dealers in monopolies have been allowed to mix themselves up as directors, contractors, or officers in these undertakings cannot be too strongly deprecated. These gentlemen are a perpetual drag upon the work when it is once commenced, owing to their relative position towards those who are permanently and solely interested in it; and besides this men possessed of genuine scientific knowledge and experience are never found in the ranks of speculators of that description. If it be necessary that a property like submarine cables should be secured for a time to the first adventurers by exclusive privileges (and it may be that temporary protection in some form is due to those who are willing to lead the way in carrying out these useful, but peculiar, enterprises), and if it be unavoidable that a class of needy and busy individuals should seek to improve their means by negotiating foreign concessions, and selling them to English companies, by all means deal with such persons in cash, and get rid of them at once and for ever, leaving the responsible managers free as well from their prejudiced or interested advice, as from their still more obnoxious control. Let the board surround themselves with the ablest and most experienced officers; but great care is requisite even here that nothing in the arrangements made with them shall have the least tendency to entangle the undertaking with patents or crotchets, or diminish the perfect control of those entrusted with the business management, by raising obstacles to the employment of the highest available talent that may from time to time present itself. The next care will be to let the route along which the cable is to be laid have the earliest and most attentive consideration. This is a question which has hitherto received far too little attention. In the case of the Atlantic Company—although two so-called surveys were made—the soundings averaged more than twenty miles apart, and gave only the most elementary view of the existing deviations along the bed of the Atlantic. The soundings near shore, on both sides, were most inadequate, those at Trinity Bay having failed to prevent the cable being laid over jagged and metallic rocks, which, as subsequent events have shown, might easily have been avoided, and on the Irish side further soundings, north and south of Valentia, might have brought to light means of avoiding the up-lying slate strata near that place, and of obtaining a more gradual descent into the deep water.
In the Red Sea, the cable in some places was laid taut over coral banks and rocky bottom, in one of which places it received serious injury. These, in all human probability, a careful survey and subsequent pilotage by the surveying officer might have enabled the contractors to have altogether avoided. In the Mediterranean scarcely any new soundings have been taken until recently, and it is in evidence by an experienced sailor that the greater part of the old ones are not at all to be depended upon. To this fact may, in all likelihood, be partially traced the failure of the Cagliari line to Malta, and the repeated deficiency in length of the cables between Sardinia and Africa.
It is not sufficient that a few casts of the lead be taken here and there at distances of twenty or thirty miles apart, ending in an unwarrantable assumption as to the character of the intervening bottom. The route should be fully and carefully surveyed. Three or four parallel lines of soundings should be taken, and each line should be sounded at intervals of two or three miles. These parallel lines should be subsequently connected by diagonal lines of soundings, taking care in no instance to accept any cast as satisfactory unless a specimen of the bottom be brought up with the lead. In this way a fair knowledge of the contour of the sub-oceanic territory to be passed over may be obtained, and the best line could be determined and chosen. Especially near shore and in anchorage a deep and muddy channel should be diligently sought for, in which the cable might repose uninjured, and be ultimately covered as in a trench. Objections may be raised to this on the grounds of time and expense. In reference to the first, the reply is obvious. Hitherto cables have been pitched overboard into the ocean with undue haste, and the consequences have been failures and universal disappointment. In future operations, therefore, there should not be such eagerness to save time. Regarding the expense, we may say that any respectable association, engaged in a zealous and honourable attempt to realize one of these all-important enterprises, has a fair claim to the aid of Government ships for surveying purposes, and might make application for such assistance with every probability of success. The utility of ocean soundings is not confined to telegraphic operations. The most important and valuable results to physical geography and meteorology would incidentally flow from such occasional employment of our national ships, while the exercise of their crews in such a service could not fail to increase their efficiency and the scientific knowledge of their officers.
Supposing the route to have been selected on the principles just advocated, the next consideration is the constitution of the cable itself. It is admitted on all hands that, everything considered, copper is the most suitable metal for its electrical conductor. But it was shewn by Professor Thomson, early in 1858, that the quality of the copper employed exercises an important influence upon its conducting power, and the more recent investigations of Dr. Matthiessen have proved that, taking 100 as the standard of purity and maximum conducting power, the several qualities of copper in the market vary in value as conductors down to a ratio as low as fourteen, which latter is the relative value possessed by the Rio Tinto copper, and by mere iron.
It appears from Dr. Matthiessen’s researches that no substance added to pure copper is capable of increasing its conductivity. It follows, therefore, that it is a question of prime importance to secure for all cables, especially for long ones, a copper conductor as near to absolute metallic purity as is practicable. It is necessary to this end that the resistance of the wire to the passage of the electric current should be measurable against a standard as nearly as possible unchanging in its own resistance. Copper itself is not a suitable metal for such a standard, seeing that it easily oxydizes, and that it is very susceptible of the effects of temperature, and varies in conductivity with every variation of heat and cold. The standard recommended by Dr. Matthiessen is an alloy made of two parts gold and one of silver, the variation in the conducting power of which he has found to be exceedingly small. Other standards are recommended by Professor Thomson, LL.D., Mr. C.F. Varley, and by M. Werner Siemens, of Berlin. Against these or some equally constant resistance, every portion of the copper wire should be measured, taking care to provide for the changing temperature of the copper by contracting that each mile of it, either by reason of purity or quantity, shall exhibit in comparison with the standard an agreed excellence of conductivity during its subjection for a given length of time to a specified degree of heat. The tests of this conducting value can be effected by a class of instruments that have recently been introduced for this purpose; the delicacy and precision of which will amply secure the object in view, and it may be added that so far as is practicable, it is highly desirable that the copper should be up to the contract standard, in purity rather than in bulk increased to make up for its alloyed condition—as every increase in circumference, unaccompanied by its normal increase of conductivity due to enlargement of the mass, develops unduly the retarding influence of induction, and is in that ratio so much opposition over and above what is natural, to the transmission of electric force.
The early conductors of submarine telegraphs were each composed of a single solid wire. This, however, was found to be inconvenient, owing to the difference between the tensile capacity of the copper and the insulator, and to the fact that the insulator is, to some extent, resilient, while the copper retains any increased length acquired by stretching. Copper, moreover, being a metal which is seldom equal throughout in texture, especially when drawn into wire, the stretching frequently found out the weak places in the single solid wire conductor, and caused it to separate after being covered with the insulator—thus producing the fatal effect known as “want of continuity.”
Several devices for the avoidance of these accidents have been proposed by Mr. Varley, Mr. Latimer Clark, and Mr. Daft. The ordinary plan, however, of spinning a number of copper wires into a special strand, and so arranging that the joints shall occur at distant intervals, and in only one wire at a time, has hitherto proved to be an ample protection against a breach of continuity, as it is scarcely possible that the whole seven wires—the usual number composing a spiral strand—should be broken at once, unless by a power which would snap the entire cable. In the early form of these strands it was objected that they did not admit of being solidly embedded in the insulator, in consequence of which a kind of tube was formed, along which water, having penetrated at any part of the cable, would flow as in an ordinary pipe. This, however, has now been entirely obviated, and complete solidity given to the conductor, by means of a viscid insulating composition, known under the name of “Chatterton’s Compound.” The central wire of the strand is coated with this compound, and the other six wires are embedded in it at the time, and by the process of twisting them around the central wire.
As regards the thickness of the conductor, the exercise of a liberal spirit in the construction of all cables, for whatever strength required, cannot be too strenuously advocated. In no case should any conductor be less than No. 14 gauge. The larger the conductor the greater the protection against the improper use of battery power, and the less the temptation to pour into it the enormous currents that have shortened the lifetime of several cables.
For long distances increased conductors are an absolute necessity with a view to rapidity of transmission; and happily few scientific facts are now better defined or more generally admitted by all the best telegraphists. The Atlantic Company were warned of this necessity by men of experience, at the time when they had just commenced the manufacture of their cable, and, had their electrician availed himself of the advice thus tendered, it is not improbable that the cable, defective as it was, might with care have been capable of transmitting messages, however imperfectly, at the present moment. The law to be acted upon in future is, that the conducting power of the copper increases with every increase of its diameter, by lessening the resistance to the passage of the current, in the ratio of the square of the increase in the diameter; while the inductive or retarding action is only increased in regular proportions, according to the increased circumference. It therefore follows that the larger the conductor the more rapidly it will do its work—a great commercial result—and one in strict accordance with common sense. This view has just been strikingly confirmed in practice. In the Mediterranean are two cables of about equal length, which have been recently laid by Messrs. Glass, Elliot and Co., the one from the coast of Africa to Minorca, having a conductor about the size of that in the Atlantic cable; and the other from Malta to Tripoli, having a conductor seven times that size. The small conductor requires sixteen cells of a Daniell’s battery to work it at the rate of thirteen words per minute; while the large conductor with three cells only, of the same dimensions can be worked with perfect signals, at a speed only limited by the capacity of the operator to send his business into the wire. There still lingers, however, in the minds of a few theorizing individuals, a leaning in favour of diminutive conductors, although it is to be hoped for their own sakes that they will not again be in a position to carry their opinions into practice at the expense of a body of shareholders.
If an hydraulic engineer were to inform us that he proposed reducing to one half the size of a supply pipe, already barely large enough, in order to convey for a given distance a double volume of water in the same space of time as had been occupied by the greater pipe in discharging the lesser quantity, we should at once assign to him a position among the sages of Laputa, described by Lemuel Gulliver. The hope of signalling with increased rapidity by reducing the size of the electrical conductor is, however, scarcely less absurd; and, it is to be hoped that neither the suggestions of a false economy, nor the visionary deductions of theoretical sciolism, will be permitted in future operations to obscure this important part of the question.
THE FUTURE OF DEEP-SEA TELEGRAPHY—(continued.)
INSULATION—TESTING—CUSHION FOR EXTERNAL SHEATH—
IN an electrical conductor it is required that its material shall offer the smallest attainable resistance to the transmission of electric force between its extremities. Conversely, the protection of such conductors from contact with foreign matter, possessed of conducting qualities, demands a substance that shall offer the strongest possible opposition to the passage of electricity through or along it.
Substances of this latter kind are called insulators, and in the case of submarine cables it is necessary that the insulating material should be indestructible by water, easily manipulated, sufficiently hard, yet free from excessive rigidity, devoid of brittleness, and yet not too elastic.
From the time when submarine cables were first introduced, down to a comparatively recent date, it has been thought that these qualities were in no material so satisfactorily combined as in gutta percha, and the immense improvements which are constantly being introduced into the selection and preparation of this article leave little scope even at present for the introduction of other modes of insulation. Lately, however, energetic and ingenious efforts have been made in various directions by persons interested in the manufacture of india rubber, with a view to introduce that substance, alone or in combination, as a substitute, believed to be superior to gutta percha in some of its electrical qualifications, and in its assumed property of enduring continuous tropical heat without injury to its texture or insulation. We have no desire to enter into any theoretical discussion upon the respective merits of these rival substances, far less to prejudge in any way the question as between gutta percha and caoutchouc. The case immediately before us is, that of a special branch of submarine telegraphy, hitherto unsuccessful, from causes equally affecting any of these forms of insulation. It behoves us, therefore, carefully to examine whether, as to cables of considerable length in deep water, necessarily involving great outlay, there are yet sufficient grounds for departing, in a matter so important, and in the absence of more definite information, from the use of a known and approved material, in favour of others which must necessarily be for some time to come in the category of speculation and experiment.
In Professor Wheatstone’s account of his experiments upon various insulators he certainly speaks very favourably of india rubber when compared with gutta percha, such as formerly was manufactured; but he goes on to observe, that later improvements in the manufacture and purification of gutta percha have so decreased the amount of its inductive discharge, and increased the perfectness of its insulation, that it now closely resembles pure india rubber in both these particulars.
Mr. Latimer Clark also, in his very able and impartial report to the Board of Trade Committee upon the same question, states, with reference to india rubber, that, although in his opinion it will eventually be found trustworthy, yet its liability to occasional decomposition, and to the absorption of water, cast a slight shade of doubt upon its character at present.
The tendency of india rubber in some of its forms to absorb water is instanced by Mr. W. Fairbairn, F.R.S., in an account of his experiments on behalf of the Board of Trade Commission, in which he states that a cable of pure india rubber indicated very good insulation before pressure was applied, but after eighty hours’ immersion the insulation was almost destroyed; while a cable composed of alternate layers of gutta percha and Chatterton’s compound, though exhibiting some variation in the insulation, resulting in part from a variable hygrometric condition of the atmosphere, did not appear, after 170 hours of immersion, at a pressure of 10,000 pounds to the square inch, to have lost any part of its power of retaining the charge, but rather to have gained in insulation.
Professor Miller also, in his report to the Board of Trade Committee, gives instances both of absorption and decomposition in india rubber; while in respect to gutta percha, he states, that sea-water appears to be eminently conducive to its preservation, and that its powers of absorbing water are almost nil.
Now, in putting forward these facts, we must again be distinctly understood as in no way urging them as conclusive upon the general question, or intended to prejudice the case for or against any particular material, which, after all, must rely for success upon its practical adaptation to the object in view. We think the whole subject is well worthy of discussion and farther experiment, which cannot fail in every respect to benefit science.
But there is a serious inference to be drawn from these and other facts in their relation to the particular subject before us. The properties of gutta percha are known; it is indestructible in sea-water; it is admittedly a first-class insulator; its preparation is constantly being improved and subjected to the severest tests; while several thousand miles of cable in which it is employed have for many years remained in perfect working order, and portions raised from the sea after ten years’ submersion had shewn improvement instead of deterioration.
The new materials, on the other hand, have not yet passed through this experimentum crucis—they lack the practical tests of lengthened submersion and continuous electrification: and until these processes have been undergone tentatively by means of short lengths of actually-submerged cable, successfully worked through during a period of several years, it would appear like rushing into an inexpedient risk if it were determined, upon existing information, however promising, to expend a capital of a quarter or half a million in one vast and possibly disastrous experiment, upon a deep-sea cable constructed of india rubber or any other novelty.
There can be no doubt, therefore, that for some time to come, at any rate, the insulation of cables for deep-sea purposes must be effected by means of gutta percha. There is not a single instance on record of the failure of this substance from any cause inherent to, or affecting, its chemical constitution; and the ready manner in which it can be applied in separate, but closely-adhering coats, enables the electrician to adjust, with great nicety, the amount of the insulation to the ratio of the conducting copper. In future cables, however, every advantage must be taken of past experience. There can be no doubt that in some of the earlier specimens of insulation air bubbles have occasionally passed unperceived, due probably to the haste with which the covering has proceeded. These can now be entirely guarded against by multiplying the number of separate layers, and by testing each layer under hydraulic pressure. The possibility of injury from this cause can further be avoided, almost with certainty, by the application of a layer of the insulating substance, known as Chatterton’s compound, between each layer of gutta percha. The best insulated conductor we have seen was enveloped in four coverings of pure gutta percha, alternated by four thin strata of the compound—one between each layer of the percha—forming altogether eight separate bands or tubes around the strand of copper, which was itself well bedded in the compound for solidity, in the manner already described.
As to the quantity of insulation to be employed in different cables, so as to combine efficiency of conduction with economy of material, this can be scientifically regulated to the ratio of the copper with the greatest nicety, by means of the tables constructed by Mr. Cromwell Varley, and published in the evidence before the Board of Trade. The following highly valuable and practical remarks of Mr. Latimer Clark, C.E., in his interesting report to the Board of Trade Committee, are also most essential to be borne in mind in regulating the proportions of copper and gutta percha. He says:—
The electrical testing of cables, both immediately after the completion of the insulating process, and during the process of applying the external armour, is a matter requiring the most patient and conscientious care.
It is gratifying to observe the almost perfect state to which this portion of the cable business has now progressed. The original Dover and Calais wires, and those of one or two succeeding cables, were never tested at all, except at the gutta percha works, and previous to the application of the external iron. The instruments used even for testing the gutta percha were of the most rudimentary character, though considered at the time to be sensitive in comparison with anything antecedent.
The galvanometer in use for some years was of the vertical description. The coils consisted of 300 yards of 25-gauge copper, covered with silk, and the magnetic needle employed was 1¼ inch in length, by ¼ inch in width, and one-sixteenth of an inch in thickness. The battery power was composed of 288 pairs of zinc and copper plates, 3¼ inches by 4¼ inches each.
Testing with these apparatus would at the present day be considered entirely futile, although in 1851 they were stated, even by Dr. Faraday, to be efficient for some delicate experiments then under his investigation. Gradually, however, the galvanometer was improved—first by increasing the quantity of wire in the coils, and afterwards by increasing further the length, and at the same time decreasing the thickness, of the wire. The horizontal form of galvanometer was then introduced, and in the most recent of this description the length of wire surrounding the coils is upwards of three miles, and the gauge of the copper is No. 40; all of this metal being first carefully tested as to its conductivity. The magnetic needle is ¾ inch wide, 2⅞ inches long, and ¼ inch thick. The battery power employed has also been more than doubled, and the old sand batteries are everywhere being discarded for the more constant apparatus introduced by Professor Daniell. The effect of all these improvements may be estimated by the fact that a loss of insulation, indicated by a deflection of 1° upon the earliest instruments, would be shewn by a reading of 10° or 15° upon those next in advance, and that a reading of 1° upon these latter would show upon the present large horizontal apparatus more than 40° of loss. In either of the two last eases the coil giving such indications would be altogether rejected. But improvement does not pause even here. It has been found that the earth’s magnetism interferes with the accuracy of an electrical test, unless the galvanometer be arranged in the plane of the magnetic meridian; and as this latter is to some extent variable, an element of error thus crept in.
Instruments are now therefore constructed having two magnets astatically connected, the north pole of the one over the south pole of the other; in order to reduce their inertia to a minimum, these are suspended in the coils by a single fibre, instead of working upon a pivot, as heretofore. The result is a very great increase in sensitiveness over even the most recent horizontal galvanometer. The system of testing all wires against a given standard, as a constant or single unit of resistance, though very recently introduced, will also undoubtedly be employed with great results in the manufacture of future cables.
It is desirable also, that hereafter, in ascertaining the electrical value of the insulator and conductor, due consideration will be given to the influence of temperature upon this question. It is not sufficient that tests should be made under the varying conditions of the atmosphere from day to day. Nor is it sufficient that the coils of insulated wire be submerged for a short time only in water even of a regulated temperature.
Before the tests are made, these coils should each be allowed to lie, during at least twenty-four hours, surrounded by water carefully maintained during the whole time at a specified heat. The insulator and the conductor would in that time be thoroughly brought under an unvarying influence, and the results would be proportionally certain and valuable.
We have dwelt at some length upon the question of insulation and testing, as being amongst the most important of the operations in submarine telegraphy. There are still, however, several other important facts to be considered in reference to the manufacture of cables. It has hitherto been the custom to surround the core of the cable next to the gutta percha with a pad or bed of hempen fibre, to serve as a cushion for the protection of the insulation from injury by the external armour with which the whole has been surrounded. This hempen protector has invariably been saturated with tar and other substances of an insulating character, for the purpose of preserving the vegetable fibre from decay.
This arrangement has, doubtless, been in many instances an insidious cause of mischief, by providing a means of patching up and concealing faults that may have occurred either during the passage of the core through the “lay plates” at the manufacturer’s, in company with the final coverings of iron wire, or subsequently during its progress to the ships and into the sea. The following facts, witnessed by the writer, will illustrate the deceptive effects liable to be produced by this arrangement. Several pieces of gutta-percha-covered copper wire, each a few yards in length, were purposely pierced through their diameter by driving in a large nail so as to lay bare the copper, thus causing a known and fatal defect of insulation to exist in each. The defects so made were severally covered round with hemp, saturated in Stockholm tar as if for the reception of the iron. The cores were then sunk under water and tested, when they all gave every indication of being quite perfect. Some of these continue perfect to the present time, after six months’ submersion. In others there have been faults artificially developed, simply by passing through them, for some twenty-four hours, continuous alternate positive and negative currents from a powerful battery. In all instances, the pressure in the deep-sea and continuous electrification would probably ruin gradually any cable circumstanced as these wires. From the variable condition shown previous to the final silence of the Atlantic and other cables, there is fair reason for the inference that they were possibly ruined by faults previously unknown, and concealed up to the time of submersion by such means as we have now stated. It seems, therefore, manifestly desirable that the cushion for the reception of the external armour should in future be composed of a conducting, not of an insulating substance. The submersion under water at the manufacturer’s, or, if the cause of injury occurred in the ship, then the first contact of the injured part with the sea, would give instant indication of the damage, and allow of instant remedy. Moreover, we venture further to suggest that this intervening cushion should be placed around the core immediately the tests have been completed at the Gutta Percha works, and not, as heretofore, at the manufacturer’s. This would save at least one handling of the cable, as the process might be going on during the final unwinding of the core after its emergence from the pressure tanks, and the padding would form a useful protection to it during its transit to the works of the manufacturer.
As to the external protecting sheath best adapted for deep-sea cables, it is at present only possible with certainty to indicate as a general principle that it resolves itself in one respect into a practical determination of specific gravities offering in great and increasing depths the most facility for submersion without strain, and in other respects into the form of cable that can be coiled and manipulated with the least risk of kinking or unsteadiness during its emission from the paying out ship. It is generally thought that mere iron will not in future be suitable. Either it must be hemp alone, or in combination with wire, or some other substance, though it may fairly be urged by the advocates of iron that some of the lighter cables have been least successful, while others of heavy specific gravity are satisfactorily working in very deep water. The most promising external covering we have seen is one in which the wires are of steel, each being covered first with hemp and subsequently with common gutta percha. This form of cable is at once light, strong, and indestructible in water. The invention of it is due, we believe, to Mr. Chatterton. An ingenious application of rattan cane to the covering of cables has also just been patented, which has been thought by several experienced persons to be well suited for some situations, but could be hardly used in mid-ocean. Mr. Latimer Clark has devised a deep-sea cable composed of numerous steel wires laid longitudinally or nearly so, and tightly wrapped by coarse hempen tape, saturated with marine glue or with gutta percha to prevent oxydation.
The laying of the external wires in a longitudinal direction is, however, strongly objected to by many experienced engineers, on account of the difficulty feared in coiling a cable so constructed, and, the liability of injury to the electrical core by the probability of fracture to one or other of the wires so laid, should any portion of the cable be suddenly bent to a sharp curve.
The various methods of applying hemp to the external protection of cables have been very numerous. Those of Rogers, De Bergue, and Rowett, are of the most promising character, but none of these new suggestions have as yet received any practical elucidation.
In concluding this part of the subject we venture to suggest that before the undertaking of any great project of deep-sea telegraphy again commit themselves upon this point, it would be most desirable to submit the question of external protection to a sound practical test, even if they had themselves to encounter the expense of doing so; but as so much private capital has been lost upon these undertakings, and as they are works of imperial as well as private necessity, it would be but fair that the Government should give assistance towards the absolute determination of the point, by causing eight or ten miles each of several cables differing in external form and specific gravity, to be manufactured at the public expense, and taken in one of her Majesty’s ships to the deepest part of the Atlantic, there to be paid out, and, if possible, hauled in again with suitable machinery. The cable that was easiest to handle would then be readily indicated, and by the same process the most suitable kind of machinery for submerging cables could be determined.
The cost of doing this would not exceed thirty or forty thousand pounds, which would be more than repaid to the public treasury in the saving that would be effected to the State during a couple of months, by obtaining the power to communicate freely, by means of the electric telegraph, with India and America alone.
The satisfactory solution of this question would give an impetus and a right direction to these undertakings, which would tend to the desirable end of removing them out of the undeserved category of naturally disastrous enterprises, into great, and permanent, and profitable institutions.
GOVERNMENT AID TO DEEP-SEA TELEGRAPHY.
OVER and above the assistance due from Government to determine experimentally the one or two remaining points upon which actual trial is desirable, it is as reasonable as it is expedient, that a generous share of substantial support should be granted by the executive towards encouraging the subscription of capital for such of the more gigantic of these important works as can be shown to have based their arrangements upon sound data and thorough bona fides.
That the Government as well as commerce are interested in their success cannot be denied, and the present aspect of political affairs in Europe and in America is admittedly such as to demand from the statesmen of this country the most anxious vigilance—not only in steering a neutral course abroad, clear of all just complaint from contending factions, while upholding by moral assent the interests of peace and civilization—but equally in providing at home, by all the aids of modern information, the most efficient and complete administration of the vast material resources of this empire, should it prove necessary, as a last resource, to protect or vindicate the property or the honour of Great Britain by an appeal to arms.
In preparations of this latter kind England has too often been found wanting at the hour of need: the advent of actual warfare has nearly always discovered that enormous pecuniary resources, freely poured into the public exchequer at the first note of national danger, have been squandered without useful result upon a host of crude and disconnected crotchets which have all had to be swept away, as in the Crimea, before British manhood could assert its supremacy, or British science lend her powerful aid in preserving the lives and diminishing the labours of our struggling squadrons.
It is lamentable to consider the enormous loss of valuable life and costly material which this state of affairs has from time to time entailed upon this country. In all matters of organization, precision, and forethought, England has confessedly been found hitherto far behind many of the continental nations, whose condition in other respects we have not been taught to look upon with envy. A modern English writer has asserted, with truth, that, owing to a want of organizing skill, one half the labour of this—the most laborious country in the world—is either wasted, or is of such an imperfect character as to require much further labour; and that, owing to the same want, the loss of life, of comfort, and of enjoyment, are positively incalculable.
Scattered abroad over the whole world are Colonial possessions, dependent on the protection, and ministering to the high position, of these islands. In peace they are one of our chief sources of national wealth. In war they would probably form prominent objects of attack, and the foremost prizes of which an enemy would seek to possess himself. In the former case, their trade and importance would be advanced enormously by the near connection which telegraphic communication with the mother country would confer upon them. In the latter ease, it is hardly too much to say that direct correspondence with head-quarters would be pretty nearly equivalent to a doubling of their material means of defence. At present, not one of these possessions is in direct telegraphic rapport with England, although the means are ready at hand, and require only such an impetus as would set them in motion, either by Government itself undertaking the work, or by the grant of such a fair share of assistance on their part as would procure the capital elsewhere.
Assistance, has, indeed, been rendered to telegraphic enterprise, or rather to telegraphic projectors; but it has not been extended in an impartial or businesslike manner, nor in a way calculated to support an honest struggle for the accomplishment of a grand national result, but more in proportion to the influence brought to bear upon the donors than with a due regard to the rightful disposal of the donation. To one has been granted an absolute unconditional guarantee: to others, subsidies, or annual dividends, contingent upon success. In no case, except in that of the Malta and Alexandria cable, now being laid by Glass, Elliot, and Co., who are to keep it in working order for seven years, has there been any examination, either into the merits of the route chosen, the structure of the cable, the appliances for submerging it, or the qualifications of the men selected to do the work.
Such a course of proceeding has ended, logically enough, in continuous disappointment and disaster, and the disappointment and disaster have as illogically been set down to some supposed inseparable and excessive risk attached to this description of adventure.
So great has been the influence of the damaging mistake, that there is room for apprehension that the present Government, having now got safely off their hands the 1,200 miles of cable ordered by their predecessors, for connecting Falmouth with Gibraltar, may for a long time, at least, be by no means disposed to render further assistance towards the raising of capital for the prosecution of submarine telegraphy. Without their aid, all enterprise in this direction must languish for many years to come, and it is submitted that so to regard a subject of vast national and international importance is unreasonable, and opposed to sound policy. It is true that one great undertaking has failed from haste and inexperience, and another through jobbery and incompetence, and that the one has inflicted loss upon the shareholders, while the loss of the other has fallen upon the public. But, surely, these events form no reason for arresting science in her onward march, or for keeping America and India severed unnecessarily from Europe, when the very experience gained from failure is only awaiting the pecuniary means for permanently effecting telegraphic union between them. Great works like these cannot be wholly effected by private persons until repeated practice has rendered them more certain, and they are precisely of that character which Government can properly foster, by means of discriminating, impartial and properly directed assistance, until they are strong enough to go alone. The enormous benefits they would bestow when once established—whether looked upon as imperial, mercantile, or scientific agents, fully warrant every attention which can be bestowed upon them by the executive of great country.
As to the mode in which the should be encouraged, the degree of encouragement that would be efficient, yet not excessive, and the amount of control to be exercised in respect to their inauguration and management, it would seem that if the Government have determined to avoid the responsibility of independent action in the matter, no better tribunal could be formed for advising the Government on all these points than a committee of the House of Commons. Their labours would be materially assisted by the report and evidence just issued from the Board of Trade, who have been engaged for eighteen mouths in investigating the scientific facts in connection with these undertakings. That document refers to most of the leading facts in the past history or future prospects of deep-sea telegraphy. It is of a highly encouraging character, and, if sound principles were once laid down, in accordance with the experience there detailed, in addition to that to be derived from such further evidence as the committee might deem it right to demand there would be little fear that the aid of Government could be used in any but a legitimate manner.
Anyhow, it is clear that deep-sea telegraphy is at a deadlock, so far as its prosecution depends upon private means. The communication is ardently desired by commercial men; but the discouragement resulting from repeated failure, and the disparaging manner in which these enterprises have come to be talked about by persons who do not understand the subject, have rendered capitalists averse from entering into them alone. It is contended that they are works of an imperial as well as of a mercantile character, and that it is just that the imperial element should bear its fair proportion of risk during at least their original establishment.
This is a state of feeling, at the present time especially, opposed to the public good. While we write, a rapid interchange of communication with India would be of inestimable value. The power of instantaneously telegraphing the American outbreak to London, and thence to India and elsewhere, at its first commencement, might very possibly have made all the difference between plenty and starvation in thousands of Lancashire homes during next winter; and it is not too much to say, that, had the cables of the Red Sea and the Atlantic Companies existed in working order during the last six months, they would have paid for themselves twice over in value made and saved to this country at large, if not even to their owners also.
The amount of gold of which England has been drained since last November is over six millions, and the loss upon American securities, on this side the Atlantic, at the commencement of the secession movement, must have been enormous, considering that upwards of sixty millions of United States’ securities are held in Great Britain alone. Had the Electric Telegraph then existed, these losses would have been very greatly mitigated; while an accurate knowledge, from day to day, of the state of exchanges at New York, would have materially checked the export of precious metals to that city, especially in large quantities, as it has frequently happened that the very gold sent out in expectation of securing, as a profit, the turn of exchange, has had the effect of so reducing the rate as to destroy all margin, and even convert the operation into a loss for the time being.
Politically the establishment of oceanic telegraphs would prove not less important. During the last two months the Government have dispatched to Canada three additional regiments, and a park of artillery, showing that they feel, in one respect, the desirability of foresight and watchfulness; but in case, from any deplorable cause, the necessity should arise for bringing this force into action, and for sending reinforcements to its support, how deeply would be felt the want of early information in the matter, and how great the loss of life and property that would, in all probability, be spared by the agency of the electric wire! In its capacity of peace-maker, it might even have spared the necessity for sending out these troops at all! Regarding the subject from every point of view, it is evident that commerce, and the state of the political horizon alike, at the present time, demand the rapid development of telegraphic communication with our distant dependencies; and it is to be hoped that, at any rate, the best mode of completing the Indian and American lines will be earnestly considered by her Majesty’s Government without delay.
RICHARD BARRETT, Printer, 13, Mark Lane, London.
Copyright © 2007 FTL Design
Last revised: 15 September, 2009
Return to Atlantic Cable main page
Research Material Needed
The Atlantic Cable website is non-commercial, and its mission is to make available on line as much information as possible.
You can help - if you have cable material, old or new, please contact me. Cable samples, instruments, documents, brochures, souvenir books, photographs, family stories, all are valuable to researchers and historians.
If you have any cable-related items that you could photograph, copy, scan, loan, or sell, please email me: [email protected]