Lives of the electricians

by William T. Jeans

It has never been denied, though often overlooked, that Mr. Cooke obtained his first idea of a telegraph from Professor Möncke of Heidelberg—a circumstance which detracts from its originality. But the matter did not rest there.

When Mr. (then Sir) W. F. Cooke died in 1879, Mr. Latimer Clark published the portion of his private correspondence which related to his first connection with Professor Wheatstone, and although Mr. Latimer Clark endeavoured to put everything in the light most favourable to Mr. Cooke, the letters of the latter in essential points confirm the case of Professor Wheatstone. For example, after writing numerous letters to his mother explaining that he was busy trying to make a telegraph, Mr. Cooke wrote on February 27th, 1837: “Dissatisfied with the results obtained, I this morning obtained Dr. Roget’s opinion, which was favourable but uncertain; next Dr. Faraday’s, who, though speaking positively as to the general results formerly, hesitated to give an opinion as to the galvanic fluid action on a voltaic magnet at a great distance when the question was put to him in that shape. I next tried Clark, a practical mechanician, who spoke positively in favour of my views, yet I felt less satisfied than ever, and called upon a Mr. Wheatstone, Professor of Chemistry at the London University, and repeated my inquiries. Imagine my satisfaction at hearing from him that he had four miles of wire in readiness, and imagine my dismay on hearing afterwards that he had been employed for months in the construction of a telegraph, and had actually invented two or three with the view of bringing them into practical use. We had a long conference, and I am to see his arrangement of wire to-morrow morning, &c.... The scientific men know little or nothing absolute on the subject. Wheatstone is the only man near the mark.” Mr. Latimer Clark accounts for the notice of Professor Wheatstone’s experiments in the Magazine of Popular Science for March, 1837, by saying that it was “evidently inserted after the remainder of the articles had been completed, and set in type,” and that Wheatstone supplied the information after Mr. Cooke’s visit to him—a gratuitous assertion which is not supported by any positive evidence. Then, again, Mr. Latimer Clark, an eminent authority upon the laws of electricity, says, concerning Mr. Cooke’s proposed telegraph, that “upon the whole the instrument, the result of such long cogitation and experiment, is disappointing, and one is not surprised at Wheatstone, with his exquisite mechanical appreciation, criticising it as severely as he did.” Moreover, he admits that the first telegraph instrument used between Camden Town and Euston was Wheatstone’s.

Not less emphatic or explicit was the statement of the case given by Professor Wheatstone himself, and moreover it contained some passages of biographical interest. Addressing Mr. Cooke, he said: “You state that you alone had succeeded in reducing to practical usefulness the electric telegraph at the time you sought my assistance. This I wholly deny. Your instrument had never been practically applied, and was incapable of being so. Mine were all founded on principles which I had previously proved by decisive experiments would produce the required effects at great distances. Your statement that I employed myself at your request in perfecting your invention in detail is equally erroneous. My time, so far as it was devoted to telegraphic researches, was exclusively occupied in perfecting my own instrument, which had nothing in common with yours, and in which I was not only known to be engaged by all my scientific friends, but which was even announced in public print before I knew of your existence. I confined myself to carrying out one of my own inventions for two reasons: First, because my experiments led me to believe that the motions of a needle could be produced at distances at which no effects of electro-magnetic attraction could be obtained; and, secondly, I did not wish to interfere with you. With regard to the subsequent development of my first telegraph, the essential principles of which are the formation of numerous circuits from a few wires and the indication of characters by the convergence of needles, I am indebted to no person whatever; it is in all its parts entirely and exclusively my own. The modifications you introduced without consulting me in the instruments for the Great Western Railway altered the simplicity and elegance of the arrangement without the slightest advantage, and I certainly should not recognise them in any published description.”

“The circumstances under which your name was allowed to take the lead in the titles of the British patents have escaped your memory. I will endeavour to recall them to you. When you first proposed partnership, you know how strongly I opposed it, and on what grounds. I said I was perfectly confident of being able to carry out my views to the end I anticipated, that I fully intended doing so, and publishing the results, then allowing any person to carry them into practical effect. I told you that, while I admired the ingenuity of your contrivance I deemed it inapplicable to the purpose proposed, and I urged that in that case the association of my name with that of others would diminish the credit I should obtain by separately publishing the result of my researches. You replied that you were not seeking scientific reputation, and therefore no difference could arise between us on that account, and that your sole object was to carry the project into profitable execution. A patent was arranged to be taken out in our joint names which should include our two separate instruments. When we met to settle the preliminaries for the English patent I was much surprised to find your name inserted first, considering that, as we put ourselves on an equality by each contributing an invention, to put my well-known name after yours, then totally unknown, might be construed into an admission of the superiority of your share. You urged that your pecuniary obligations were the greater, and that as I intended to leave negotiations with you, your authority might be less respected if your name appeared second, and that your invention was the more valuable—an assumption I did not admit, and the event proved I was right. But we agreed that in subsequent patents the order should alternate. Some time after we met to settle the Scotch patent draft, for which you had prepared the declaration. I was again surprised to find the same order of precedence repeated, and I objected to it as contrary to our previous understanding. You said it had been done without your knowledge, but objected to the alteration on the ground of delay. After discussion we made a new arrangement, that on my allowing your name to stand on the British patents, mine should take the lead in all foreign ones. It was resolved afterwards that an American patent should be obtained, and when I attended to sign the preliminary papers, I found that again, without any notice to me, my name was made to follow yours. I refused to sign the papers, and you then consented to keep your word. The only reason you alleged was that your authority as manager would be diminished if you appeared as second partner.

“When I had attained some complete results, I invited you to the College to see them, and before describing or showing the new experiments and instruments, I proposed conditions: That having, at my own expense, undertaken a series of investigations which led to important consequences greatly increasing the pecuniary value of the patents, and having invented new instruments which, besides being applicable to all the purposes for which the existing arrangements could be applied, might also be profitably applied to other purposes to which the previous instruments were not at all adapted, I required as a compensation that I should retain the exclusive right of manufacturing them and all instruments I should construct involving the same principles, and also the privilege of employing them exclusively for domestic and official purposes. To these conditions you assented, and afterwards I showed you the completed instruments, and read to you a list of the further experiments. You confirmed your assent. On this occasion you breathed not a word respecting the claim since put forward to be considered the joint inventor of my new instruments.

“You ask me to acknowledge that ‘I, having certain improvements on our joint invention in progress depending fundamentally upon principles first discovered and applied by you, had asked as a favour,’ &c. It is unjust to urge such an acknowledgment upon me, and I state plainly that nothing shall compel me to make it. My instruments are original combinations involving a great number of points entirely new. With equal justice Mr. Ronalds might call upon me to declare that he is the joint inventor, because, like him, I use a revolving dial with letters—or Professor Steinheil complain of my suppressing his name because, in one of my most recent important modifications I employ, as he has done, the magneto-electric machine—as you to put forth that claim, because in some of my new instruments I have employed magneto-electric attraction, which you had done before me in your instrument; or with the same reason might Mr. Morse call upon me to proclaim him to be joint inventor because he, independently of you, has employed an electro-magnet to move machinery intended for a telegraph. One of your complaints is, that in the notices of my experiments in Belgium the employment of two wires for an electric telegraph was not specifically mentioned as a discovery of yours. Such a claim on your part has no foundation, for, without going further back, Ronalds’ two telegraphs—two telegraphs on different principles, which I myself proposed before I knew you,—and Steinheil’s telegraph, with which I was acquainted before yours, had two wires. You forget that it is my electric telegraph, and not yours, that is in daily use. And, lastly, you forget that, had it not been for my exclusive attention to it since I first conceived the idea, a practical telegraph might still have remained an unaccomplished purpose.

“Do not, however, misunderstand me. Far be it from me to underrate your exertions; they have been very great, and absolutely indispensable to the success of our joint undertaking. Without your zeal and perseverance and practical skill, what has been done would not have been so readily effected; but on the other hand, I may say, that had you entered the field without me, your zeal, perseverance, and money would have been thrown away.”

His subsequent as well as his previous inventions afford the strongest evidence of his originality. His inventions were not more distinguished for ingenuity than for permanent usefulness, and they had this unusual characteristic, that nearly every one of them became the parent of a considerable offspring. These form his most enduring monument, and a simple record of them forms his best vindication.

In 1840 he produced three inventions at one birth—his dial telegraph, his printing telegraph, and his electric clock. Each of these instruments was worked by utilising one of the great discoveries previously made in electro-magnetism. It was known that when an electric current is sent through a wire coiled round a piece of soft iron, the iron becomes a magnet. If the current is stopped for a moment, the iron instantly ceases to act as a magnet. When the piece of iron is magnetic, it will attract another piece of iron, and as the attraction ceases as soon as the current ceases, the iron can then by means of a spring be made to resume its original position. Thus by frequently interrupting an electric current, a piece of iron held in its place by a small spring can be made to move to and fro as often as it is attracted. Professor Wheatstone invented a method of regulating the application of the current to such a magnet, and of converting the to-and-fro motion of the iron into symbols. The piece of mechanism that regulated the current was a wheel called a commutator or communicator; around its circumference were twenty-four teeth; and each tooth was made to act as a conductor of electricity in this way: Under the teeth of the communicator there was a metallic circle which was connected with the telegraph wire; and in this metallic circle twenty-four pieces of wood were inserted at equal distances apart; so that the teeth of the communicator, which was connected by wire with the battery, at one moment touched the conducting metal of the circle underneath it, and thus imparted a current to the telegraph wire, while at the next turn a pace round they rested on the non-conducting wood, by which the current was prevented from passing from the communicator wheel to the telegraph wire. In a complete revolution of such a wheel the current would be twenty-four times established and as often interrupted; and each of these twenty-four alternations was made to indicate a letter of the alphabet at the other end of the wire by means of a piece of mechanism like a clock. When the current passed along the wire, it electrified a magnet, which then drew towards it an armature (a piece of iron). The movement of this armature (forward by electricity and backward again by a spring) acted like a pendulum in moving a wheel, which in turn moved a hand on a dial containing the letters of the alphabet. Just as at each movement of the pendulum of a clock, a wheel moves one tooth forward; so at each movement of the armature by an electric current, a twenty-four toothed wheel was moved one tooth forward, and at each such movement the hand on the dial moved from one letter of the alphabet to the next one. If, for instance, the indicator hand stood at A and it was desired to transmit E, this would be done by moving the communicator wheel four teeth onward; in doing that four successive currents would be transmitted to the indicator, the hand of which would consequently move over B, C, D, and then reach E, where a pause would indicate that this was the letter intended to be read. This was called Wheatstone’s electro-magnetic telegraph, because it was worked by an electric current from a battery electrifying a magnet.

In 1841 he invented a machine in which magnets produced electricity sufficient to work the telegraph. Hence it was called a magneto-electric machine, and the telegraph worked by it was called a magneto-electric telegraph. In 1840 he explained that magneto-electricity was of momentary duration as contrasted with the continuous action of electro-magnetism. The magneto-electric machine then in use consisted of a coil or coils of insulated wire being made to revolve in the vicinity of a magnet, or the magnet revolving in the vicinity of the insulated coils of wire, and this apparatus only produced a series of shocks, or instantaneous as compared with continuous currents. His new invention combined several of these machines into one by so uniting their coils as to form one continuous circuit, thereby producing the same effect as a perfectly continuous current. He said this magneto-electric machine could be used for many purposes for which a voltaic battery had been employed. The patent for it was taken out in his own name.