Lives of the electricians

by William T. Jeans

In 1859 the Board of Trade selected Professor Wheatstone as a member of the committee appointed to inquire into the subject of submarine cables with special reference to the Atlantic cable. To that committee he supplied an elaborate report which would fill fifty pages of this volume, “On the circumstances which influence the inductive discharge of submarine telegraph cables.” He was also a member of the scientific committee appointed in 1864 to advise the Atlantic Telegraph Company as to the manufacture, laying, and working of the cables of 1865 and 1866.

In 1848 Lord Palmerston made a remark about the telegraph that was at the time regarded as a jest. He said the day would come when a minister, if asked in Parliament whether war had broken out in India, would reply, “Wait a minute, I’ll just telegraph to the Governor General, and let you know.” At that time two or three months usually elapsed between the sending of a message and the receipt of an answer from Calcutta to London; and hence the remark of Lord Palmerston was derided as a joke. But in 1855 the electric telegraph performed a feat which astonished the nations of Europe. On the 2nd of March the Czar Nicholas died at St. Petersburg at one o’clock; and the same afternoon the Earl of Clarendon announced his death in the House of Lords—the intelligence having been received by two different lines of telegraph. Two years afterwards two different schemes were promoted for connecting Europe with India by telegraph; but this was not successfully accomplished till eight years afterwards. Three years before the Palmerstonian jest of 1848 became an accomplished fact, Professor Wheatstone communicated to Lord Palmerston the effects of a new telegraphic invention which seemed nearly as incredible as the idea of telegraphing to India appeared a few years previously. The noble lord was at Oxford University receiving his honorary degree, and was watched by Sir Henry Taylor at an evening party as the Professor gave him a somewhat prolonged explanation of his new invention for facilitating telegraphy. “The man of science,” says Sir Henry, “was slow, the man of the world seemed attentive; the man of science was copious, the man of the world let nothing escape him; the man of science unfolded the anticipated results—another and another, the man of the world listened with all his ears: and I was saying to myself, ‘His patience is exemplary, but will it last for ever?’ when I heard the issue:—‘God bless my soul, you don’t say so! I must get you to tell that to the Lord Chancellor.’ And the man of the world took the man of science to another part of the room, hooked him on to Lord Westbury, and bounded away like a horse let loose in a pasture.”

If it be true that men of the world regarded with impatience the ingenious devices of Professor Wheatstone, very different was the reception accorded to them by the prince of modern scientists. In the beginning of the following year (19th January, 1858) Professor Faraday wrote the following letter to him: “While thinking of your beautiful telegraphs it occured to me that perhaps you would not think ill of my proposing to give an account of the magneto-electric telegraph and the recording telegraph on a Friday evening after Easter—about the end of May or June. I suppose all will be safe by that time. I think that by the electric lamp and a proper lens, we might throw the image of the face on to the wall, and so we may illustrate the action to the whole audience.” The proposed lecture was delivered by Professor Faraday in the Royal Institution on June 11th, 1858, and his subject was “Wheatstone’s electric telegraph in relation to science (being an argument in favour of the full recognition of science as a branch of education).” That lecture was very interesting, not only as indicating the progress made in the telegraph, but as showing his high appreciation of the inventive ingenuity which had accelerated that progress. So far from representing the telegraph as “no invention” he spoke of it as a series of inventions. “It teaches us to be neglectful of nothing,” he said; “not to despise the small beginnings, for they precede of necessity all great things in the knowledge of science, either pure or applied. It teaches a continual comparison of the small and great, and that under differences almost approaching the infinite: for the small as often comprehends the great in principle as the great does the small.” As to the work done by Professor Wheatstone, he said: “Without referring to what he had done previously, it may be observed that in 1840 he took out patents for electric telegraphs, which included, amongst other things, the use of the electricity from magnets at the communicators—the dial face—the step-by-step motion—and the electro-magnet at the indicator. At the present time, 1858, he has taken out patents for instruments containing all these points; but these instruments are so altered and varied in character above and beyond the former, that an untaught person could not recognise them. In the first instruments powerful magnets were used, and keepers[7] with heavy coils associated with them. When magnetic electricity was first discovered, the signs were feeble, and the mind of the student was led to increase the results by increasing the force and size of the instruments. When the object was to obtain a current sufficient to give signals through long circuits, large apparatus were employed, but these involved the inconveniences of inertia and momentum; the keeper was not set in motion at once, nor instantly stopped; and if connected directly with the reading indexes, these circumstances caused an occasional uncertainty of action. Prepared by its previous education, the mind could perceive the disadvantages of these influences, and could proceed to their removal.... The alternations or successions of currents produced by the movement of the keeper at the communicator, pass along the wire to the indicator at a distance; there each one for itself confers a magnetic condition on a piece of soft iron, and renders it attractive or repulsive of small permanent magnets; and these, acting in turn on a propelment, cause the index to pass at will from one letter to another on the dial face. The first electro-magnets, i.e., those made by the circulation of an electric current round a piece of soft iron, were weak; they were quickly strengthened, and it was only when they were strong that their laws and actions could be successfully investigated. But now they are required small, yet potential; and it was only by patient study that Wheatstone was able so to refine the little electro-magnets at the indicator as that they shall be small enough to consist with the fine work there employed, able to do their appointed work when excited in contrary directions by the brief currents flowing from the original common magnet, and unobjectionable in respect of any resistance they might offer to these tell-tale currents. These small transitory electro-magnets attract and repel certain permanent magnetic needles, and the to-and-fro motion of the latter is communicated by a propelment to the index, being there converted into a step-by-step motion. Here everything is of the finest workmanship; the propelment itself requires to be watched by a lens, if its action is to be observed; the parts never leave hold of each other; the holes of the axes are jewelled; the moving parts are most carefully balanced, a consequence of which is that agitation of the whole does not disturb the parts, and the telegraph works just as well when it is twisted about in the hands, or placed on board a ship or in a railway carriage, as when fixed immovably. All this delicacy of arrangement and workmanship is introduced advisedly; for the inventor considers that refined and perfect workmanship is more exact in its action, more unchangeable by time and use, and more enduring in its existence, than that which, being heavier, must be coarser in its workmanship, less regular in its action, and less fitted for the application of force by fine electric currents.... Now,” added Faraday, “there was no chance in these developments;—if there were experiments, they were directed by the previously acquired knowledge;—every part of the investigation was made and guided by the instructed mind.... The beauty of electricity, or of any other force, is not that the power is mysterious and unexpected, but that it is under law, and that the taught intellect can even now govern it largely.”

The instrument which Faraday described in such appreciative terms has superseded the step-by-step instrument which was invented in 1840. The new instrument, like the old one, has a dial with the letters of the alphabet round the edge, and when in operation the indicating hand or finger points successively to each letter forming the message, which can thus be read by anyone. The sending instrument also has a dial round which are the letters of the alphabet, and projecting from each letter is a brass key or stud. The new mechanism inside this instrument is so ingeniously designed that when the sender of a message turns round a small handle which puts in motion the magneto-electric apparatus so as to generate electric currents, the indicating finger on the receiving dial moves round till it is stopped at the desired letter. This stoppage is effected by the sender depressing the brass stud which represents the desired letter. By this depression of any particular stud, the currents of electricity are cut off just when the indicating finger reaches the letter on the receiving dial corresponding to that of the depressed stud at the sending instrument; and the indicating finger remains at that letter till the stud of another letter is depressed, whereupon the indicating finger moves along the receiving dial till it reaches again the letter corresponding to that of the depressed stud. No knowledge of electrical science or of mechanics is needed to work this instrument, the hidden mechanism of which cannot be easily described in popular language. Surely it is an illustration of the classic adage that the highest art is to conceal art.

The working of this instrument excelled all others in simplicity; and at the same time Professor Wheatstone invented one which exceeded all others in rapidity. The former became known as Wheatstone’s A, B, C instrument, the latter as Wheatstone’s automatic fast speed printing instrument. The latter is so constructed that the passage of the current is regulated by means of a perforated strip of paper. The apparatus consists of three parts—the perforator, the transmitter, and the receiver. The perforator has keys which when pressed down by an operator punch in a strip of paper combinations of holes, which represent letters of the alphabet, thus

One person working a perforator can simultaneously punch duplicate messages, but only one strip of perforated paper can be put into the transmitter, which draws it forward with a continuous motion. Two small pins, one on each side, are underneath the strip of paper, and whenever one of these pins comes to a perforated hole it momentarily rises through it, and imparts sufficient electricity from the battery to the telegraph wire to move a pen at the other end of the wire, so as to make a mark in ink on a clean strip of paper passing through the receiving instrument. The ink marks thus produced in combinations represent letters of the alphabet, namely,

The receiver is thus a recording instrument so exact and sensitive that it mechanically and rapidly imprints on a strip of paper dots, dashes, and spaces, which, in a sense, correspond with the holes perforated in the tape passing through the transmitter, at the other end of the wire. When this apparatus was invented it was represented as capable of forwarding messages at the rate of 500 letters per minute, being five times faster than any other system then in use.

In 1868 the inventor stated that although for rapidity of transmission his automatic instrument had never been surpassed, he did not expect that the existing instruments would in all cases be given up for it. He believed it would be very useful on all “lines of great traffic,” and particularly on those lines over which newspaper intelligence is sent. In 1870 the telegraph lines of the United Kingdom were acquired by the Government—a step which Professor Wheatstone advocated as the best means of cheapening messages and extending the telegraph to places unapproached by the Telegraph Companies. Let us see how his expectations have been realised.