From Pearson's Magazine, April 1900
Pictures by Telegraph
by Charles Emmerson Cook
You know that your words can be flashed by telegraph. Do you know that it is equally possible to telegraph your features?
"Very likely," you answer; for the seemingly impossible has happened so persistently during this wonderful age that you are not disposed seriously to doubt any scientific assertion, however startling or extra ordinary. Yet your knowledge of the miraculous triumphs of modern invention reminds you that not a few among the great achievements have proved valuable only as they illustrated some scientific theory. So you bring forth the business man's argu- ments.
"The machine may bear out the inventor's theories, but has it any practical value? Is it not too expensive to operate commercially? Is not its mechanism so complicated that it will readily get out of order? And even granting that it may prove simple and not too expensive, is the thing of any use, and does anyone really want it?"
Such practical catechising has sealed the doom of many a clever invention. It wastes its force, however, against the Telediagraph.
Too expensive ? Scarcely more so than the ordinary telegraph machine, thousands of which are in constant use. Too complicated ? On the contrary; it is surprisingly simple. Of any use, and does anyone want it? Ask the newspaper editor who, when a new politician springs suddenly to fame hundreds of miles away, wants to give his readers an authentic likeness of the candidate in the next edition. Ask London's Chief of Police, when he is eager to head off a dangerous criminal. If the editor can show a picture of the great candidate within an hour of his nomination; if the criminal cannot get fifty miles away without being rounded up by his own likeness; then surely the picture- telegraphing machine proves its practical value, and may, like the telegraph itself, be counted hereafter a commercial and social necessity.
The inventor of this wonderful instrument is Ernest A. Hummel, of St. Paul, Minnesota. Though a young man, a watchmaker, he has, thus early in life, been the first to give practical form to an idea which for thirty years has been the cherished dream of many who are versed in the science of electricity. He started work on the instruments, or at least on his theory, in May, 1895.
At that time, while visiting his parents in Germany, he saw a newspaper article with which was published a portrait. The likeness was sketched over perpendicular lines, some drawn across, others up and down, the picture forming squares. "With those lines I could see how confusing it would be to an operator, so I worked on the theory of doing away with the crossing lines. It took me about a day to get my ideas into shape, and then I commenced to work on the patterns "
When Mr Hummel had completed his task and in January, 1898, set up his first machines in the office of the New York Herald, those invited to witness the experiments saw two cabinets, on the tops of which, in glass cases, were the fruits of his ingenuity and skill. One cabinet contained the transmitter, the machine by which the original drawing was sent. The other, the receiver, so called since it responds to the action of the transmitter and "receives," or reproduces, the likeness. During this first experiment a circuit of eight miles' length was employed, and, though the reproduction was clear and accurate, the attempt showed where a few improvements might be made with a view to convenience and simplicity.
So Mr. Hummel gave another year to the problem, and on April 19th, 1899, made a new test with his improved machines. Meantime, the New York Herald, which controls the invention, had caused machines to be placed in the offices of the Chicago Times Herald, the St. Louis Republic, the Boston Herald, and the Philadelphia Inquirer. On this historical day the offices in these widely remote cities were connected with the office in New York, and when all was ready, received simultaneously and over the same wire, an accurate picture of "the first gun fired at Manila." Then other pictures were sent back by telegraph, over the single circuit, from these cities to New York; with which remarkable achievement the invention carried itself beyond the stage of experiment to open up a new field in journalistic enterprise.
The principle of the telediagraph is amazingly simple-- so simple, indeed, that it seems incredible that no one hitherto has applied it successfully to the sending of pictures. When Professor Morse invented the system of transmitting ideas by causing his little electrical device to tick off a series of dots and dashes, he discovered the principle which, fifty years later. has been so cleverly utilised in picture-telegraphing. In truth, strange though it may seem, this later application of the idea is the more simple, because the dots and dashes of the telegraph need translating before they can be understood by the layman, whereas the lines produced by the telediagraph themselves form the picture, which is practically complete in itself the moment it is received.
To procure a "circuit," or unbroken path for the electric current, two connected wires or other conductors are necessary. A telegraph wire reaches from New York to Chicago, but there can be no circuit until a current, sent over this wire, can return to its starting point in New York. It has long been known that the earth is as good a conductor as any wire, and that, by connecting the wire with the ground at New York and Chicago, the earth itself would complete the circuit and thus allow a return of the current.
It is also known that electricity travels round the globe sixteen times, or 400,000 miles, in one second; consequently, the hundredth part of a second required for a current to complete the circuit between New York and Chicago is a period so small as to be practically instantaneous. It is by suddenly breaking, or opening, such a circuit, by means of the telegraph key, that the faint and loud " ticks " are produced; and a faint, quick tap on the key in Chicago is instantly repeated in New York.
Formerly, the meaning of these "ticks," light or loud, short or long, was understood only by their sound, and left no written record at the point at which they were received. But after this method had been in practice several years, it was discovered that the dots and dashes indented in the long, narrow slip of paper that ran under the starting key in Chicago, for example, could be easily re- produced by running a similar slip of paper under the receiving key in New York. It is on this simple and familiar scientific principle that Mr. Hummel has based his invention.
The equipment consists of two machines, almost identical in construction, the first being called the " transmitter," the second the " receiver." Each is provided with an eight-inch cylinder, which may be made to revolve by a delicate system of clockwork so finely regulated that both instruments work together to a nicety.
Above each cylinder rests a fine platinum needle, or stylus, not unlike the point in a telegraph key. A sheet of tin-foil, six inches by eight inches, ready to wrap round the transmitter's cylinder, and a sheet of ordinary carbon manifold-copying paper of the same dimensions, which, when placed between two sheets of blank paper, is to be wrapped round the receiver's cylinder--these complete the chief requirements.
Having these essentials at hand, the artist and the operators may begin their work. Let us suppose that a likeness of Richard Croker is to be telegraphed from New York to Boston. With a photograph of the subject before him, the artist draws its duplicate on the sheet of tin-foil, leaving a margin of about a half-inch on all sides. For this work, either pen or brush may be used; but, of first importance, the liquid must have more consistency than ink, and must be a non-conductor of electricity. An alcoholic solution of shellac is found most suitable for the purpose.
This likeness, drawn in shellac on a piece of tin-foil, is then bent carefully round the cylinder of the receiver in New York. A sharp "click, click" from the New York operator, answered by a mysterious " tick, tack " from the Boston end, announces that the duplex wires have been balanced, and that the machines are adjusted. The little platinum point is made to rest on the outer edge of the tin-foil, completing the circuit; a pressure on the starting button in front of the apparatus turns on the current.
There is a bee-hum of whirring wheels; the cylinder bearing the picture begins its first revolution. While the stylus rests on the clear tin-foil, the circuit is not disturbed, and no effect is made on the cylinder of the receiving machine in Boston, which is turning in perfect sympathy. But how is it when the platinum point comes in contact with the shellac lines of the drawing or, rather, when the shellac line intrudes itself between the tin-foil and the stylus? The first result obviously, is to interrupt, or open, the circuit in the New York machine, since the shellac refuses to conduct the current; the second and simultaneous effect is to close the circuit in the receiving machine in Boston, which remains closed as long as the New York circuit remains open.
This closing of the receiving circuit causes the needle at that end of the wire to drop instantly against the paper on its own cylinder, which, revolving, draws the carbon under the needle-point, making a fine black line on each of the sheets of plain paper, between which the carbon has been placed. As long as the non-conducting shellac interrupts the current in New York, the tiny needle in Boston will remain pressed against its cylinder and drawing its fine black line. When the New York needle again touches the clear tin-foil, the Boston needle jumps away from its cylinder and no longer leaves its mark against the paper. So on for a complete revolution; wherever a shellac line occurs in the original drawing on the transmitter, the platinum point of the receiver records its fine black line against the carbon.
At the end of every revolution the cylinders stop for just the smallest fraction of a second, so that the time of making another revolution may be corrected by the transmitter. Both cylinders then move to the left, automatically, a distance of one fifty-sixth of an inch. After which, another revolution and another series of black lines so close to the first as to form a part of them!
Thus, line after line is added to the picture, each line so near its neighbour as to leave no perceptible space between, until, when the complete portrait is shown, only a microscopic examination could disclose the simple fact that it is composed of thin parallel lines, all of the same width, and differing only in length as the shellac shading on the tin-foil may have required. If you have taken the trouble to time the process you will see that this remarkable result of sending a portrait by telegraph through a space of more than two hundred miles has been accomplished in from twenty to thirty minutes. We might have sent it simultaneously and as easily to half-a-dozen other cities thousands of miles apart.
Little need be done to the picture once it is taken from the receiver, except for the local artist to touch it up a little, strengthen- ing a line here or a bit of shading the there, in order to emphasise the general effect.
When we contemplate the scientific and political significance of the telediagraph, its marvellous possibilities seem almost incredible. Its chief wonder, however, lies in the fact that it has been so long in reaching us; like many a great invention its basic principle, now that we know it, is so very clear and simple that for lack of a poorer compliment to inventive genius, we grudgingly ask: "How is it no one thought of that before?"
(C) Marius Rensen