The Family's Interest in Speech Improvement—Early Life-Influence ofSir Charles Wheatstone—He Comes to America—Visible Speech and theMohawks—The Boston School for Deaf Mutes—The Personality of Bell.
The men of the Bell family, for three generations, have interested themselves in human speech. The grandfather, the father, and the uncle of Alexander Graham Bell were all elocutionists of note. The grandfather achieved fame in London; the uncle, in Dublin; and the father, in Edinburgh. The father applied himself particularly to devising means of instructing the deaf in speech. His book onVisible Speechexplained his method of instructing deaf mutes in speech by the aid of their sight, and of teaching them to understand the speech of others by watching their lips as the words are spoken.
Alexander Graham Bell was born in Edinburgh in 1847, and received his early education in the schools of that city. He later studied at Warzburg, Germany, where he received the degree of Doctor of Philosophy. He followed very naturally in the footsteps of his father, taking an early interest in the study of speech. He was especially anxious to aid his mother, who was deaf.
As a boy he exhibited a genius for invention, as well as for acoustics. Much of this was duo to the wise encouragement of his father. He himself has told of a boyhood invention.
My father once asked my brother Melville and myself to try to make a speaking-machine, I don't suppose he thought we could produce anything of value, in itself. But he knew we could not even experiment and manufacture anything which even tried to speak, without learning something of the voice and the throat; and the mouth—all that wonderful mechanism of sound production in which he was so interested.
So my brother and I went to work. We divided the task—he was to make the lungs and the vocal cords, I was to make the mouth and the tongue. He made a bellows for the lungs and a very good vocal apparatus out of rubber. I procured a skull and molded a tongue with rubber stuffed with cotton wool, and supplied the soft parts of the throat with the same material Then I arranged joints, so the jaw and the tongue could move. It was a great day for us when we fitted the two parts of the device together. Did it speak? It squeaked and squawked a good deal, but it made a very passable imitation of "Mam-ma—Mam-ma." It sounded very much like a baby. My father wanted us to go on and try to get other sounds, but we were so interested in what we had done we wanted to try it out. So we proceeded to use it to make people think there was a baby in the house, and when we made it cry "Mam-ma," and heard doors opening and people coming, we were quite happy. What has become of It? Well, that was across the ocean, in Scotland, but I believe the mouth and tongue part that I made is in Georgetown somewhere; I saw it not long ago.
The inventor tells of another boyhood invention that, though it had no connection with sound or speech, shows his native ingenuity. Again we will tell it in his own words.
I remember my first invention very well. There were several of us boys, and we were fond of playing around a mill where they ground wheat into flour. The miller's son was one of the boys, and I am afraid he showed us how to be a good deal of a nuisance to his father. One day the miller called us into the mill and said, "Why don't you do something useful instead of just playing all the time?" I wasn't afraid of the miller as much as his son was, so I said, "Well, what can we do that is useful?" He took up a handful of wheat, ran it over in his hand and said: "Look at that! If you could manage to get the husks off that wheat, that would be doing something useful!"
So I took some wheat home with me and experimented. I found the husks came off without much difficulty. I tried brushing them off and they came off beautifully. Then it occurred to me that brushing was nothing but applying friction to them. If I could brush the husks off, why couldn't the husks be rubbed off?
There was in the mill a machine—I don't know what it was for—but it whirled its contents, whatever it was, around in a drum. I thought, "Why wouldn't the husks come off if the raw wheat was whirled around in that drum?" So back I went to the miller and suggested the idea to him.
"Why," he said, "that's a good idea." So he called his foreman and they tried it, and the husks came off beautifully, and they've been taking husks off that way ever since. That was my very first invention, and it led me to thinking for myself, and really had quite an influence on my way and methods of thought.
Up to his sixteenth year young Bell's reading consisted largely of novels, poetry, and romantic tales of Scotch heroes. But in addition he was picking up some knowledge of anatomy, music, electricity, and telegraphy. When he was but sixteen years of age his father secured for him a position as teacher of elocution and this necessarily turned his thought into more serious channels. He now spent his leisure studying sound. During this period he made several discoveries in sound which were of some small importance.
When he was twenty-one years of age he went to London and there had the good fortune to come to the attention of Charles Wheatstone and Alex J. Ellis. Ellis was at that time president of the London Philological Society, and had translated Helmholtz'sThe Sensation of Toneinto English. He had made no little progress with sound, and demonstrated to Bell the methods by which German scientists had caused tuning-forks to vibrate by means of electro-magnets and had combined the tones of several tuning-forks in an effort to reproduce the sound of the human voice. Helmholtz had performed this experiment simply to demonstrate the physical basis of sound, and seems to have had no idea of its possible use in telephony.
That an electro-magnet could vibrate a tuning-fork and so produce sound was an entirely new and fascinating idea to the youth. It appealed to his imagination, quickened by his knowledge of speech. "Why not an electrical telegraph?" he asked himself. His idea seems to have been that the electric current could carry different notes over the wire and reproduce them by means of the electro-magnet. Although Bell did not know it, many others were struggling with the same problem, the answer to which proved most elusive. It gave Bell a starting-point, and the search for the telephone began.
Sir Charles Wheatstone was then England's leading man of science, and so Bell sought his counsel. Wheatstone received the young man and listened to his statement of his ideas and ambitions and gave him every encouragement. He showed him a talking-machine which had recently been invented by Baron de Kempelin, and gave him the opportunity to study it closely. Thus Bell, the eager student, the unknown youth of twenty-two, came under the influence of Wheatstone, the famous scientist and inventor of sixty-seven. This influence played a great part in shaping Bell's career, arousing as it did his passion for science. This decided him to devote himself to the problem of reproducing sounds by mechanical means. Thus a new improvement in the means of human communication was being sought and another pioneer of science was at work.
The death of the two brothers of the young scientist from tuberculosis, and the physician's report that he himself was threatened by the dread malady, forced a change in his plans and withdrew him from an atmosphere which was so favorable to the development of his great ideas. He was told that he must seek a new climate and lead a more vigorous life in the open. Accompanied by his father, he removed to America and at the age of twenty-six took up the struggle for health in the little Canadian town of Brantford.
He occupied himself by teaching his father's system of visible speech among the Mohawk Indians. In this work he met with no little success. At the same time he was gaining in bodily vigor and throwing off the tendency to consumption which had threatened his life. He did not forget the great idea which filled his imagination and eagerly sought the telephone with such crude means as were at hand. He succeeded in designing a piano which, with the aid of the electric current, could transmit its music over a wire and reproduce it.
While lecturing in Boston on his system of teaching visible speech, the elder Bell received a request to locate in that city and take up his work in its schools. He declined the offer, but recommended his son as one entirely competent for the position. Alexander Graham Bell received the offer, which he accepted, and he was soon at work teaching the deaf mutes in the school which Boston had opened for those thus afflicted. He met with the greatest success in his work, and ere long achieved a national reputation. During the first year of his work, 1871, he was the sensation of the educational world. Boston University offered him a professorship, in which position he taught others his system of teaching, with increased success.
The demand for his services led him to open a School of Vocal Physiology. He had made some improvements in his father's system for teaching the deaf and dumb to speak and to understand spoken words, and displayed great ability as a teacher. His experiments with telegraphy and telephony had been laid aside, and there seemed little chance that he would turn from the work in which he was accomplishing so much for so many sufferers, and which was bringing a comfortable financial return, and again undertake the tedious work in search for a telephone.
Fortunately, Bell was to establish close relationships with those who understood and appreciated his abilities and gave him encouragement in his search for a new means of communication. Thomas Sanders, a resident of Salem, had a five-year-old son named Georgie who was a deaf mute. Mr. Sanders sought Bell's tutelage for his son, and it was agreed that Bell should give Georgie private lessons for the sum of three hundred and fifty dollars a year. It was also arranged that Bell was to reside at the Sanders home in Salem. He made arrangements to conduct his future experiments there.
Another pupil who came to him about this time was Mabel Hubbard, a fifteen-year-old girl who had lost her hearing and consequently her powers of speech, through an attack of scarlet fever when an infant. She was a gentle and lovable girl, and Bell fell completely in love with his pupil. Four years later he was to marry her and she was to prove a large influence in helping him to success. She took the liveliest interest in all of his experiments and encouraged him to new endeavor after each failure. She kept his records and notes and wrote his letters. Through her Bell secured the support of her father, Gardiner G. Hubbard, who was widely known as one of Boston's ablest lawyers. He was destined to become Bell's chief spokesman and defender.
Hubbard first became aware of Bell's inventive genius when the latter was calling one evening at the Hubbard home in Cambridge. Bell was illustrating some mysteries of acoustics with the aid of the piano. "Do you know," he remarked, "that if I sing the note G close to the strings of the piano, the G string will answer me?"
This did not impress the lawyer, who asked its significance.
"It is a fact of tremendous importance," answered Bell. "It is evidence that we may some day have a musical telegraph which will enable us to send as many messages simultaneously over one wire as there are notes on that piano."
From that time forward Hubbard took every occasion to encourage Bell to carry forward his experiments in musical telegraphy.
As a young man Bell was tall and slender, with jet-black eyes and hair, the latter being pushed back into a curly tangle. He was sensitive and high-strung, very much the artist and the man of science. His enthusiasms were intense, and, once his mind was filled with an idea, he followed it devotedly. He was very little the practical business man and paid scant attention to the small, practical details of life. He was so interested in visible speech, and so keenly alert to the pathos of the lives of the deaf mutes, that he many times seriously considered giving over all experiments with the musical telegraph and devoting his entire life and energies to the amelioration of their condition.
The Cellar at Sanderses'—Experimental Beginnings—Magic Revived inSalem Town—The Dead Man's Ear—The Right Path—Trouble andDiscouragement—The Trip to Washington—Professor Joseph Henry—TheBoston Workshop—The First Faint Twang of the Telephone—EarlyDevelopment.
Alexander Graham Bell had not resided at the Sanderses' home very long before he had fitted the basement up as a workshop. For three years he haunted it, spending all of his leisure time in his experiments. Here he had his apparatus, and the basement was littered with a curious combination of electrical and acoustical devices—magnets, batteries, coils of wire, tuning-forks, speaking-trumpets, etc. Bell had a great horror that his ideas might be stolen and was very nervous over any possible intrusion into his precious workshop. Only the members of the Sanders family were allowed to enter the basement. He was equally cautious in purchasing supplies and equipment lest his very purchases reveal the nature of his experiments. He would go to a half-dozen different stores for as many articles. He usually selected the night for his experiments, and pounded and scraped away indefatigably, oblivious of the fact that the family, as well as himself, was sorely in need of rest.
"Bell would often awaken me in the middle of the night," says Mr. Sanders, "his black eyes blazing with excitement. Leaving me to go down to the cellar, he would rush wildly to the barn and begin to send me signals along his experimental wires. If I noticed any improvement in his apparatus he would be delighted. He would leap and whirl around in one of his 'war-dances,' and then go contentedly to bed. But if the experiment was a failure he would go back to his work-bench to try some different plan."
In common with other experimenters who were searching for the telephone, Bell was experimenting with a sort of musical telegraph. Eagerly and persistently he sought the means that would replace the telegraph with its cumbersome signals by a new device which would enable the human voice itself to be transmitted. The longer he worked the greater did the difficulties appear. His work with the deaf and dumb was alluring, and on many occasions he seriously considered giving over his other experiments and devoting himself entirely to the instruction of the deaf and dumb and to the development of his system of making speech visible by making the sound-vibrations visible to the eye. But as he mused over the difficulties in enabling a deaf mute to achieve speech nothing else seemed impossible. "If I can make a deaf mute talk," said Bell, "I can make iron talk."
One of his early ideas was to install a harp at one end of the wire and a speaking-trumpet at the other. His plan was to transmit the vibrations over the wire and have the voice reproduced by the vibrations of the strings of the harp. By attaching a light pencil or marker to a cord or membrane and causing the latter to vibrate by talking against it, he could secure tracings of the sound-vibrations. Different tracings were secured from different sounds. He thus sought to teach the deaf to speak by sight.
At this time Bell enjoyed the friendship of Dr. Clarence J. Blake, an eminent Boston aurist, who suggested that the experiments be conducted with a human ear instead of with a mechanical apparatus in imitation of the ear. Bell eagerly accepted the idea, and Doctor Blake provided him with an ear and connecting organs cut from a dead man's head. Bell soon had the ghastly specimen set up in his workshop. He moistened the drum with glycerine and water and, substituting a stylus of hay for the stapes bone, he obtained a wonderful series of curves which showed the vibrations of the human voice as recorded by the ear. One can scarce imagine a stranger picture than Bell must have presented in the conduct of those experiments. We can almost see him with his face the paler in contrast with his black hair and flashing black eyes as he shouted and whispered by turns into the ghastly ear. Surely he must have looked the madman, and it is perhaps fortunate that he was not observed by impressionable members of the public else they would have been convinced that the witches had again visited old Salem town to ply their magic anew. But it was a new and very real and practical sort of magic which was being worked there.
His experiments with the dead man's ear brought to Bell at least one important idea. He noted that, though the ear-drum was thin and light, it was capable of sending vibrations through the heavy bones that lay back of it. And so he thought of using iron disks or membranes to serve the purpose of the drum in the ear and arrange them so that they would vibrate an iron rod. He thought of connecting two such instruments with an electrified wire, one of which would receive the sound-vibrations and the other of which would reproduce them after they had been transmitted along the wire. At last the experimenter was on the right track, with a conception of a practicable method of transmitting sound. He now possessed a theoretical knowledge of what the telephone he sought should be, but there yet remained before him the enormous task of devising and constructing the apparatus which would carry out the idea, and find the best way of utilizing the electrical current for this work.
Bell was now at a critical point in his career and was confronted by the same difficulty which assails so many inventors. In his constant efforts to achieve a telephone he had entirely neglected his school of vocal physiology, which was now abandoned. Georgie Sanders and Mabel Hubbard were his only pupils. Though Sanders and Hubbard were genuinely interested in Bell and his work, they felt that he was impractical, and were especially convinced that his experiments with the ear and its imitations were entirely useless. They believed that the electrical telegraph alone presented possibilities, and they told Bell that unless he would devote himself entirely to the improvement of this instrument and cease wasting time and money over ear toys that had no commercial value they would no longer give him financial support. Hubbard went even further, and insisted that if Bell did not abandon his foolish notions he could not marry his daughter.
Bell was almost without funds, his closest friends now seemed to turn upon him, and altogether he was in a sorry plight. Of course Sanders and Hubbard meant the best, yet in reality they were seeking to drive their protégé in exactly the wrong direction. As far back as 1860 a German scientist named Philipp Reis produced a musical telephone that even transmitted a few imperfect words. But it would not talk successfully. Others had followed in his footsteps, using the musical telephone to transmit messages with the Morse code by means of long and short hums. Elisha Gray, of Chicago, also experimented with the musical telegraph. At the transmitting end a vibrating steel tongue served to interrupt the electric current which passed over the wire in waves, and, passing through the coils of an electro-magnet at the receiving end, caused another strip of steel located near the magnet to vibrate and so produce a tone which varied with the current.
All of these developments depended upon the interruption of the current by some kind of a vibrating contact. The limitations which Sanders and Hubbard sought to impose upon Bell, had they been obeyed to the letter, must have prevented his ultimate success. In a letter to his mother at this time, he said:
I am now beginning to realize the cares and anxieties of being an inventor. I have had to put off all pupils and classes, for flesh and blood could not stand much longer such a strain as I have had upon me.
But good fortune was destined to come to Bell along with the bad. On an enforced trip to Washington to consult his patent attorney—a trip he could scarce raise funds to make—Bell met Prof. Joseph Henry. We have seen the part which this eminent scientist had played in the development of the telegraph. Now he was destined to aid Bell, as he had aided Morse a generation earlier. The two men spent a day over the apparatus which Bell had with him. Though Professor Henry was fifty years his senior and the leading scientist in America, the youth was able to demonstrate that he had made a real discovery.
"You are in possession of the germ of a great invention," said Henry, "and I would advise you to work at it until you have made it complete."
"But," replied Bell, "I have not got the electrical knowledge that is necessary."
"Get it," was Henry's reply.
This proved just the stimulus Bell needed, and he returned to Boston with a new determination to perfect his great idea.
Bell was no longer experimenting in the Sanderses' cellar, having rented a room in Boston in which to carry on his work. He had also secured the services of an assistant, one Thomas Watson, who received nine dollars a week for his services in Bell's behalf. The funds for this work were supplied by Sanders and Hubbard jointly, but they insisted that Bell should continue his experiments with the musical telegraph. Though he was convinced that the opportunities lay in the field of telephony, Bell labored faithfully for regular periods with the devices in which his patrons were interested. The remainder of his time and energy he put upon the telephone. The basis of his telephone was still the disk or diaphragm which would vibrate when the sound-waves of the voice were thrown against it. Behind this were mounted various kinds of electro-magnets in series with the electrified wire over which the inventor hoped to send his messages. For three years they labored with this apparatus, trying every conceivable sort of disk. It is easy to pass over those three years, filled as they were with unceasing toil and patient effort, because they were drab years when little of interest occurred. But these were the years when Bell and Watson were "going to school," learning how to apply electricity to this new use, striving to make their apparatus talk. How dreary and trying these years must have been for the experimenters we may well imagine. It requires no slight force of will to hold oneself to such a task in the face of failure after failure.
By June of 1875 Bell had completed a new Instrument. In this the diaphragm was a piece of gold-beater's skin, which Bell had selected as most closely resembling the drum in the human ear. This was stretched tight to form a sort of drum, and an armature of magnetized iron was fastened to its middle. Thus the bit of iron was free to vibrate, and opposite it was an electro-magnet through which flowed the current that passed over the line. This acted as the receiver. At the other end of the wire was a sort of crude harmonica with a clock spring, reed, and magnet. Bell and Watson had been working upon their crude apparatus for months, and finally, on June 2d, sounds were actually transmitted. Bell was afire with enthusiasm; the first great step had been taken. The electric current had carried sound-vibrations along the wire and had reproduced them. If this could be done a telephone which would reproduce whole words and sentences could be attained.
[Illustration: ALEXANDER GRAHAM BELL]
[Illustration: THOMAS A. WATSON]
So great was Bell's enthusiasm over this achievement that he succeeded in convincing Sanders and Hubbard that his idea was practical, and they at last agreed to finance him in his further experiments with the telephone. A second membrane receiver was constructed, and for many more weeks the experiments continued. It was found that sounds were carried from instrument to instrument, but as a telephone they were still far from perfection. It was not until March of 1876 that Bell, speaking into the instrument in the workroom, was heard and understood by Watson at the other instrument in the basement. The telephone had carried and delivered an intelligible message.
The telephone which Bell had invented, and on which he received a patent on his twenty-ninth birthday, consisted of two instruments similar in principle to what we would now call receivers. If you will experiment with the receiver of a modern telephone you will find that it will transmit as well as receive sound. The heart of the transmitter was an electro-magnet in front of which was a drum-like membrane with a piece of iron cemented to its center opposite the magnet. A mouthpiece was arranged to throw the sounds of the voice against the diaphragm, and as the membrane vibrated the bit of iron upon it—acting as an armature—induced currents corresponding to the sound-waves, in the coils of the electro-magnet.
Passing over the line the current entered the coils of the tubular electro-magnet in the receiver. A thin disk of soft iron was fastened at the end of this. When the current-waves passed through the coils of the magnet the iron disk was thrown into vibration, thus producing sound. As it vibrated with the current produced by the iron on the vibrating membrane in the transmitter acting as an armature, transmitter and receiver vibrated in unison and so the same sound was given off by the receiver and made audible to the human ear as was thrown against the membrane of the transmitter by the voice.
The patent issued to Bell has been described as "the most valuable single patent ever issued." Certainly it was destined to be of tremendous service to civilization. It was so entirely new and original that Bell found difficulty in finding terms in which to describe his invention to the patent officials. He called it "an improvement on the telegraph," in order that it might be identified as an improvement in transmitting intelligence by electricity. In reality the telephone was very far from being a telegraph or anything in the nature of a telegraph.
As Bell himself stated, his success was in large part due to the fact that he had approached the problem from the viewpoint of an expert in sound rather than as an electrician. "Had I known more about electricity and less about sound," he said, "I would never have invented the telephone." As we have seen, those electricians who worked from the viewpoint of the telegraph never got beyond the limitations of the instrument and found that with it they could transmit signals but not sounds. Bell, with his knowledge of the laws of speech and sound, started with the principles of the transmission of sound as a basis and set electricity to carrying the sound-vibrations.
Boll's Impromptu Trip to the Exposition—The Table Under theStairs—Indifference of the Judges—Enter Don Pedro, Emperor ofBrazil—Attention and Amazement—Skepticism of the Public—The Aidof Gardiner Hubbard—Publicity Campaign.
The Philadelphia Centennial Exposition—America's first great exposition—opened within a month after the completion of the first telephone. The public knew nothing of the telephone, and before it could be made a commercial success and placed in general service the interest of investors and possible users had to be aroused. The Centennial seemed to offer an unusual opportunity to place the telephone before the public. But Bell, like Morse, had no money with which to push his invention. Hubbard was one of the commissioners of the exposition, and exerted his influence sufficiently so that a small table was placed in an odd corner in the Department of Education for the exhibition of the apparatus. The space assigned was a narrow strip between the stairway and the wall.
But no provision was made to allow Bell himself to be present. The young inventor was almost entirely without funds. Sanders and Hubbard had paid nothing but his room rent and the cost of his experiments. He had devoted himself to his inventions so entirely that he had lost all of his professional income. So it was that he was forced to face the prospect of staying in Boston and allowing this opportunity of opportunities to pass unimproved. His fiancée, Miss Hubbard, expected to attend the exposition, and had heard nothing of Bell's inability to go. He went with her to the station, and as the train was leaving she learned for the first time that he was not to accompany her. She burst into tears at the disappointment. Seeing this, Bell dashed madly after the train and succeeded in boarding it. Without money or baggage, he nevertheless succeeded in arriving in Philadelphia.
Bell arrived at the exposition but a few days before the judges were to make their tour of inspection. With considerable difficulty Hubbard had secured their promise that they would stop and examine the telephone. They seemed to regard it as a toy not worth their attention, and the public generally had displayed no interest in the device. When the day for the inspection arrived Bell waited eagerly. As the day passed his hope began to fall, as there seemed little possibility that the judges would reach his exhibit. The Western Union's exhibit of recording telegraphs, the self-binding harvester, the first electric light, Gray's musical telegraph, and other prominently displayed wonders had occupied the attention of the scientists. It was well past supper-time when they came to Bell's table behind the stairs, and most of the judges were tired out and loudly announced their intention of quitting then and there.
At this critical moment, while they were fingering Bell's apparatus indifferently and preparing for their departure, a strange and fortunate thing occurred. Followed by a group of brilliantly attired courtiers, the Emperor of Brazil appeared. He rushed up to Bell and greeted him with a warmth of affection that electrified the indifferent judges. They watched the scene in astonishment, wondering who this young Bell was that he could attract the attention and the friendship of the Emperor. The Emperor had attended Bell's school for deaf mutes in Boston when it was at the height of its success, and had conceived a warm admiration for the young man and taken a deep interest in his work. The Emperor was ready to examine Bell's invention, though the judges were not. Bell showed him how to place his ear to the receiver, and he then went to the transmitter which had been placed at the other end of the wire strung along the room. The Emperor waited expectantly, the judges watched curiously. Bell, at a distance, spoke into the transmitter. In utter wonderment the Emperor raised his head from the receiver. "My God," he cried, "it talks!"
Skepticism and indifference were at an end among the judges, and they eagerly followed the example of the Emperor. Joseph Henry, the most venerable savant of them all, took his place at the receiver. Though his previous talk with Bell, when the telephone was no more than an idea, should perhaps have prepared him, he showed equal astonishment, and instantly expressed his admiration. Next followed Sir William Thomson, the hero of the cable and England's greatest scientist. After his return to England Thomson described his sensations.
"I heard," he said, "'To be or not to be … there's the rub,' through an electric wire; but, scorning monosyllables, the electric articulation rose to higher flights, and gave me passages from the New York newspapers. All this my own ears heard spoken to me with unmistakable distinctness by the then circular-disk armature of just such another little electro-magnet as this I hold in my hand."
Thomson pronounced Bell's telephone "the most wonderful thing he had seen in America." The judges had forgotten that they were hungry and tired, and remained grouped about the telephone, talking and listening in turn until far into the evening. With the coming of the next morning Bell's exhibit was moved from its obscure corner and given the most prominent place that could be found. From that time forward it was the wonder of the Centennial.
[Illustration: PROFESSOR BELL'S VIBRATING REED]
[Illustration: PROFESSOR BELL'S FIRST TELEPHONE]
[Illustration: THE FIRST TELEPHONE SWITCHBOARD USED IN NEW HAVEN,CONN, FOR EIGHT SUBSCRIBERS]
[Illustration: EARLY NEW YORK EXCHANGE
Boys were employed as operators at first, but they were not adapted to the work so well as girls.]
[Illustration: PROFESSOR BELL IN SALEM, MASS., AND MR. WATSON INBOSTON, DEMONSTRATING THE TELEPHONE BEFORE AUDIENCES IN 1877]
[Illustration: DR BELL AT THE TELEPHONE OPENING THE NEW YORK-CHICAGOLINE, OCTOBER 18, 1892]
Yet but a small part of the public could attend the exposition and actually test the telephone for themselves. Many of these believed that it was a hoax, and general skepticism still prevailed. Business men, though they were convinced that the telephone would carry spoken messages, nevertheless insisted that it presented no business possibilities. Hubbard, however, had faith in the invention, and as Bell was not a business man, he took upon himself the work of promotion—the necessary, valuable work which must be accomplished before any big idea or invention may be put at the service of the public. Hubbard's first move was to plan a publicity campaign which should bring the new invention favorably to the attention of all, prove its claims, and silence the skeptics. They were too poor to set up an experimental line of their own, and so telegraph lines were borrowed for short periods wherever possible, demonstrations were given and tests made. The assistance of the newspapers was invoked and news stories of the tests did much to popularize the new idea.
An opportunity then came to Bell to lecture and demonstrate the telephone before a scientific body in Essex. He secured the use of a telegraph line and connected the hall with the laboratory in Boston. The equipment consisted of old-fashioned box 'phones over a foot long and eight inches square, built about an immense horseshoe magnet. Watson was stationed in the Boston laboratory. Bell started his lecture, with Watson constantly listening over the telephone. Bell would stop from time to time and ask that the ability of the telephone to transmit certain kinds of sounds be illustrated. Musical instruments were played in Boston and heard in Essex; then Watson talked, and finally he was instructed to sing. He insisted that he was not a singer, but the voices of others less experienced in speaking over the crude instruments often failed to carry sufficiently well for demonstration purposes. So Watson sang, as best he could, "Yankee Doodle," "Auld Lang Syne," and other favorites. After the lecture had been completed members of the audience were invited to talk over the telephone. A few of them mustered confidence to talk with Watson in Boston, and the newspaper reporters carefully noted down all the details of the conversation.
The lecture aroused so much interest that others were arranged. The first one had been free, but admission was charged for the later lectures and this income was the first revenue Bell had received for his invention. The arrangements were generally the same for each of the lectures about Boston. The names of Longfellow, of Holmes, and of other famous American men of letters are found among the patrons of some of the lectures in Boston. Bell desired to give lectures in New York City, but was not certain that his apparatus would operate at that distance over the lines available. The laboratory was on the third floor of a rooming-house, and Watson shouted so loud in his efforts to make his voice carry that the roomers complained. So he took blankets and erected a sort of tent over the instruments to muffle the sound. When the signal came from Bell that he was ready for the test, Watson crawled into the tent and began his shoutings. The day was a hot one, and by the time that the test had been completed Watson was completely wilted. But the complaints of the roomers had been avoided. For one of the New York demonstrations the services of a negro singer with a rich barytone voice had been secured. Watson had no little difficulty in rehearsing him for the part, as he objected to placing his lips close to the transmitter. When the time for the test arrived he persisted in backing away from the mouthpiece when he sang, and, though Watson endeavored to hold the transmitter closer to him, his efforts were of no avail. Finally Bell told Watson that as the negro could not be heard he would have to sing himself. The girl operator in the laboratory had assembled a number of her girl friends to watch the test, and Watson, who did not consider himself a vocalist, did not fancy the prospect. But there was no one else to sing, the demonstration must proceed, and finally Watson struck up "Yankee Doodle" in a quavering voice.
The negro looked on in disgust. "Is that what you wanted me to do, boss?"
"Yes," replied the embarrassed Watson.
"Well, boss, I couldn't sing like that."
The telegraph wires which were borrowed to demonstrate the utility of the telephone proved far from perfect for the work at hand. Many of the wires were rusted and the insulation was poor. The stations along the line were likely to cut in their relays when the test was in progress, and Bell's instruments were not arranged to overcome this retardation. However, the lectures were a success from the popular viewpoint. The public flocked to them and the fame of the telephone grew. So many cities desired the lecture that it finally became necessary for Bell to employ an assistant to give the lecture for him. Frederick Gower, a Providence newspaper man, was selected for this task, and soon mastered Bell's lecture. It was then possible to give two lectures on the same evening, Bell delivering one, Gower the other, and Watson handling the laboratory end for both.
Gower secured a contract for the exclusive use of the telephone in New England, but failed to demonstrate much ability in establishing the new device on a business basis. How little the possibilities of the telephone were then appreciated we may understand from the fact that Gower exchanged his immensely valuable New England rights for the exclusive right to lecture on the telephone throughout the country.
The success of these lectures made it possible for Bell to marry, and he started for England on a wedding-trip. The lectures also aroused the necessary interest and made it possible to secure capital for the establishment of telephone lines. It also determined Hubbard in his plan of leasing the telephones instead of selling them. This was especially important, as it made possible the uniformity of the efficient Bell system of the present day.
The First Telephone Exchange—The Bell TelephoneAssociation—Theodore N. Vail—The Fight with the WesternUnion—Edison and Blake Invent Transmitters—Last Effort of theWestern Union—Mushroom Companies and Would-be Inventors—TheControversy with Gray—Dolbear's Claims—The Drawbaugh Case—On aFirm Footing.
Through public interest had been aroused in the telephone, it was still very far from being at the service of the nation. The telephone increases in usefulness just in proportion to the number of your acquaintances and business associates who have telephones in their homes or offices. Instruments had to be manufactured on a commercial scale, telephone systems had to be built up. While the struggles of the inventor who seeks to apply a new idea are often romantic, the efforts of the business executives who place the invention, once it is achieved, at the service of people everywhere, are not less praiseworthy and interesting.
A very few telephones had been leased to those who desired to establish private lines, but it was not until May of 1877 that the first telephone system was established with an exchange by means of which those having telephones might talk with one another. There was a burglar-alarm system in Boston which had wires running from six banks to a central station. The owner of this suggested that telephones be installed in the banks using the burglar-alarm wires. Hubbard gladly loaned the instruments for the purpose. Instruments were installed in the banks without saying anything to the bankers, or making any charge for the service. One banker demanded that his telephone be removed, insisting that it was a foolish toy. But even with the crude little exchange the first system proved its worth. Others were established in New York, Philadelphia, and other cities on a commercial basis. A man from Michigan appeared and secured the perpetual rights for his State, and for his foresight and enterprise he was later to be rewarded by the sale of these rights for a quarter of a million dollars. The free service to the Boston bankers was withdrawn and a commercial system installed there.
But these exchanges served but a few people, and were poorly equipped. There was, of course, no provision for communication between cities. With the telephone over a year old, less than a thousand instruments were in use. But Hubbard, who was directing the destinies of the enterprise during Bell's absence in Europe, decided that the time had come to organize. Accordingly the Bell Telephone Association was formed, with Bell, Hubbard, Sanders, and Watson as the shareholders. Sanders was the only one of the four with any considerable sum of money, and his resources were limited. He staked his entire credit in the enterprise, and managed to furnish funds with which the fight for existence could be carried on. But a business depression was upon the land and it was not easy to secure support for the telephone.
The entrance of the Western Union Telegraph Company into the telephone field brought the affairs of the Bell company to a crisis. As we have seen, the telegraph company had developed into a great and powerful corporation with wires stretching across the length and breadth of the land and agents and offices established in every city and town of importance. Once the telephone began to be used as a substitute for the telegraph in conveying messages, the telegraph officials awoke to the fact that here, possibly, was a dangerous rival, and dropped the viewpoint that Bell's telephone was a mere plaything. They acquired the inventions of Edison, Gray, and Dolbear, and entered the telephone field, announcing that they were prepared to furnish the very best in telephonic communication. This sudden assault by the most powerful corporation in America, while it served to arouse public confidence in the telephone, made it necessary for Hubbard to reorganize his forces and find a general capable of doing battle against such a foe.
Hubbard's political activities had brought to him a Presidential appointment as head of a commission on mail transportation. In the course of the work for the Government he had come much in contact with a young man named Theodore N. Vail, who was head of the Government mail service. He had been impressed by Vail's ability and had in turn introduced Vail to the telephone and aroused his enthusiasm in its possibilities. This Vail was a cousin of the Alfred Vail who was Morse's co-worker, and who played so prominent a part in the development of the telegraph. His experience in the Post-office Department had given him an understanding of the problems of communication in the United States, and had developed his executive ability. Realizing the possibilities of the telephone, he relinquished his governmental post and cast his fortunes with the telephone pioneers, becoming general manager of the Bell company.
The Western Union strengthened its position by the introduction of a new and improved transmitter. This was the work of Thomas Edison, and was so much better than Bell's transmitter that it enabled the Western Union to offer much better telephonic equipment. As we have seen, Bell's transmitter and receiver were very similar, being about the same as the receiver now in common use. In his transmitter Edison placed tiny bits of carbon in contact with the diaphragm. As the diaphragm vibrated under the sound-impulses the pressure upon the carbon granules was varied. An electric current was passed through the carbon particles, whose electrical resistance was varied by the changing pressure from the diaphragm. Thus the current was thrown into undulations corresponding to the sound-waves, and passed over the line and produced corresponding sounds in the receiver. Much stronger currents could be utilized than those generated by Bell's instrument, and thus the transmitter was much more effective for longer distances.
Bell returned from Europe to find the affairs of his company in a sorry plight. Only the courage and generalship of Vail kept it in the field at all. Bell was penniless, having failed to establish the telephone abroad, even as Morse before him had failed to secure foreign revenue from his invention. Bell's health failed him, and as he lay helpless in the hospital his affairs were indeed at a low ebb. At this juncture Francis Blake, of Boston, came forward with an improved transmitter which he offered to the Bell company in exchange for stock. The instrument proved a success and was gladly adopted, proving just what was needed to make possible successful competition with the Western Union.
Prolonged patent litigation followed, and after a bitter legal struggle the Western Union officials became convinced of two things: one, that the Bell company, under Vail's leadership, would not surrender; second, that Bell was the original inventor of the telephone and that his patent was valid. The Western Union, however, seemed to have strong basis for its claim that the new transmitter of the Bell people was an infringement of Edison's patent. A compromise was arranged between the contestants by which the two companies divided the business of furnishing communication by wire in the United States. This agreement proved of the greatest benefit to both organizations, and did much to make possible the present development and universal service of both the telephone and telegraph. By the terms of the agreement the Western Union recognized Bell's patent and agreed to withdraw from the telephone business. The Bell company agreed not to engage in the telegraph business and to take over the Western Union telephone system and apparatus, paying a royalty on all telephone rentals. Experience has demonstrated that the two businesses are not competitive, but supplement each other. It is therefore proper that they should work side by side with mutual understanding.
Success had come at last to the telephone pioneers. Other battles were still to be fought before their position was to be made secure, but from the moment when the Western Union admitted defeat the Bell company was the leader. The stock of the company advanced to a point where Bell, Hubbard, Sanders, and Watson found themselves in the possession of wealth as a reward for their pioneering.
The Western Union had no sooner withdrawn as a competitor of the Bell organization than scores of small, local companies sprang up, all ready to pirate the Bell patent and push the claims of some rival inventor. A very few of them really tried to establish telephone systems, but the majority were organized simply to sell stock to a gullible public. They stirred up a continuous turmoil, and made much trouble for the larger company, though their patent claims were persistently defeated in the courts.
Most of the rival claimants who sprang up, once the telephone had become an established fact and had proved its value, were men of neither prominence nor scientific attainments. Of a very different type was Elisha Gray, whose work we have before noticed, and who now came forward with the claim that he had invented a telephone in advance of Bell. Gray was a practical man of real scientific attainments, but, as we have noticed, his efforts in search of a telephone were from the viewpoint of a musical telegraph and so destined to failure. It has frequently been stated that Gray filed his application for a patent on a telephone of his invention but a few minutes after Bell, and so Bell wrested the honor from him by the scantiest of margins. A careful reading of the testimony brought out in Gray's suit against Bell does not support such a statement. While Bell filed an application for a patent on a completed, invention, Gray filed, a few moments later, a caveat. This was a document, stating that he hoped to invent a telephone of a certain kind therein stated, and would serve to protect his rights until he should have time to perfect it. Thus Gray did not have a completed invention, and he later failed to perfect a telephone along the lines described in his caveat. The decision of the court supported Bell's claims in full.
Another of the Western Union's telephone experts, Professor Dolbear, of Tufts College, also sought to make capital of his knowledge of the telephone. He based his claims upon an improvement of the Reis musical telegraph, which had formed the starting-point for so many experimenters. The case fell flat, however, for when the apparatus was brought into court no one could make it talk.
None of the attacks upon Bell's claim to be the original inventor of the telephone aroused more popular interest at the time than the famous Drawbaugh case. Daniel Drawbaugh was a country mechanic with a habit of reading of the new inventions in the scientific journals. He would work out models of many of these for himself, and, showing them very proudly, often claim them as his own devices. Drawbaugh was now put forward by the opponents of the Bell organization as having invented a telephone before Bell. It was claimed that he had been too poor to secure a patent or to bring his invention to popular notice. Much sympathy was thus aroused for him and the legal battle was waged to interminable length, with the usual result. Bell's patent was again sustained, and Drawbaugh's claims were pronounced without merit.
Many other legal battles followed, but the dominance of the Bell organization, resting upon the indisputable fact that Bell was the first man to conceive and execute a practical telephone, could not be shaken. The telephone business was on a firm footing: it had demonstrated its real service to the public; it had become a necessity; and, under the able leadership of Vail, was fast extending its field of usefulness.
The First Suggestion—Morse Sends Messages Through theWater—Trowbridge Telegraphs Through the Earth—Experiments ofPreece and Heaviside in England—Edison Telegraphs from MovingTrains—Researches of Hertz Disclose the Hertzian Waves.
Great as are the possibilities of the telegraph and the telephone in the service of man, these instruments are still limited to the wires over which they must operate. Communication was not possible until wires had been strung; where wires could not be strung communication was impossible. Much yet remained to be done before perfection in communication was attained, and, though the public generally considered the telegraph, and the telephone the final achievement, men of science were already searching for an even better way.
The first suggestion that electric currents carrying messages might some day travel without wires seems to have come from K.A. Steinheil, of Munich. In 1838 he discovered that if the two ends of a single wire carrying the electric current be connected with the ground a complete circuit is formed, the earth acting as the return. Thus he was able to dispense with one wire, and he suggested that some day it might be possible to eliminate the wire altogether. The fact that the current bearing messages could be sent through the water was demonstrated by Morse as early as 1842. He placed plates at the termini of a circuit and submerged them in water some distance apart on one side of a canal. Other plates were placed on the opposite side of the waterway and were connected by a wire with a sensitive galvanometer in series to act as a receiver. Currents sent from the opposite side were recorded by the galvanometer and the possibility of communication through the water was established. Others carried these experiments further, it being even suggested that messages might be sent across the Atlantic by this method.
But Bell's greatest contribution to the search for wireless telegraphy was not his direct work in this field, but the telephone itself. His telephone receiver provided the wireless experimenters with an instrument of extreme sensitiveness by which they were able to detect currents which the mirror galvanometer could not receive. While experimenting with a telephone along a telegraph line a curious phenomenon was noticed. The telephone experimenters heard music very clearly. They investigated and found that another telegraph wire, strung along the same poles, but at the usual distance and with the usual insulation, was being used for a test of Edison's musical telephone. Many other similar tests were made and the effect was always noted. In some way the message on one line had been conveyed across the air-gap and had been recorded by the telephones on the other line. It was decided that this had been caused by induction.
Prof. John Trowbridge, of Harvard University, might well be termed the grandfather of wireless telegraphy. He made the first extensive investigation of the subject, and his experiments in sending messages without wires and his discoveries furnished information and inspiration for those who were to follow. His early experiments tested the possibility of using the earth as a conductor. He demonstrated that when an electric current is sent into the earth it spreads from that point in waves in all directions, just as when a stone is cast into a pond the ripples widen out from that point, becoming fainter and fainter until they reach the shore. He further found that these currents could be detected by grounding the terminals of a telephone circuit. Telegraphy through the earth was thus possible. However, the farther the receiving station was from the sending station the wider must be the distance between the telephone terminals and the smaller the current received. Professor Trowbridge did not find it possible to operate his system at a sufficient distance to make it of value, but he did demonstrate that the currents do travel through the earth and that they can be set to carrying messages.
Professor Trowbridge also revived the idea of telegraphing across the Atlantic by utilizing the conductivity of the sea-water to carry the currents. In working out the plan theoretically he discovered that the terminals on the American side would have to be widely separated—one in Nova Scotia and the other in Florida—and that they would have to be connected by an insulated cable. Two widely separated points on the coast of France were suggested for the other terminals. He also calculated that very high voltages would be necessary, and the practical difficulties involved made it seem certain that such a system would cost far too much to construct and to operate to be profitable.
Trowbridge suggested the possibility of using such a system for establishing communication between ships at sea. Ship could communicate with ship, over short distances, during a fog. A trailing wire was to be used to increase the sending and receiving power, and Trowbridge believed that with a dynamo capable of supplying current for a hundred lights, communication could be established at a distance of half a mile.
Not satisfied with the earth or the sea as a medium for carrying the current, Trowbridge essayed to use the air. He believed that this was possible, and that it would be accomplished at no distant date. He believed, however, that such a system could not be operated over considerable distances because of the curvature of the earth. He endeavored to establish communication through the air by induction. He demonstrated that if one coil of wire be set up and a current sent through it, a similar coil facing it will have like currents induced within it, which may be detected with a telephone receiver. He also determined that the currents were strongest in the receiving coil when it was placed in a plane parallel with the sending coil. By turning the receiving coil about until the sound was strongest in the telephone receiver, it was thus possible to determine the direction from which the messages were coming. Trowbridge recognized the great value of this feature to a ship at sea.
But these induced currents could only be detected at a distance by the use of enormous coils. To receive at a half-mile a coil of eight hundred feet radius would have been necessary, and this was obviously impossible for use on shipboard. So these experiments also developed no practical improvement in the existing means of communication. But Professor Trowbridge had demonstrated new possibilities, and had set men thinking along new lines. He was the pioneer who pointed the way to a great invention, though he himself failed to attain it.
Bell followed up Trowbridge's suggestions of using the water as a medium of communication, and in a series of experiments conducted on the Potomac River established communication between moving ships.
Professor Dolbear also turned from telephone experimentation to the search for the wireless. He grounded his wires and sent high currents into the earth, but improved his system and took another step toward the final achievement by adding a large induction coil to his sending equipment. He suggested that the spoken word might be sent as well as dots and dashes, and so sought the wireless telephone as well as the wireless telegraph. Like his predecessors, his experiments were successful only at short distances.
The next application of the induction telegraph was to establish communication with moving trains. Several experimenters had suggested it, but it remained for Thomas A. Edison to actually accomplish it. He set up a plate of tin-foil on the engine or cars, opposite the telegraph wires. Currents could be induced across the gap, no matter what the speed of the train, and, traveling along the wires to the station, communication was thus established. Had Edison continued his investigation further, instead of turning to other pursuits, he might have achieved the means of communicating through the air at considerable distances.
These experiments by Americans in the early 'eighties seemed to promise that America was to produce the wireless telegraph, as it had produced the telegraph and the telephone. But the greatest activity now shifted to Europe and the American men of science failed to push their researches to a successful conclusion. Sir W.H. Preece, an Englishman, brought himself to public notice by establishing communication with the Isle of Wight by Morse's method. Messages were sent and received during a period when the cable to the island was out of commission, and thus telegraphing without wires was put to practical use.
Preece carried his experiments much further. In 1885 he laid out two great squares of insulated wire, a quarter of a mile to the side, and at a distance of a quarter of a mile from each other. Telephonic communication was established between them, and thus he had attained wireless telephony by induction. In 1887, another Englishman, A.W. Heaviside, laid circuits over two miles long on the surface and other circuits in the galleries of a coal-mine three hundred and fifty feet below, and established communication between the circuits. Working together, Preece and Heaviside extended the distances over which they could communicate. Preece finally decided that a combination of conduction and induction was the best means of wireless communication. He grounded the wire of his circuit at two points and raised it to a considerable height between these points. Preece's work was to put the theories of Professor Trowbridge to practical use and thus bring the final achievement a step nearer.
But conduction and induction combined would not carry messages to a distance that would enable extensive communication. A new medium had yet to be found, and this was the work of Heinrich Hertz, a young German scientist. He was experimenting with two flat coils of wire, as had many others before him, but one of the coils had a small gap in it. Passing the discharge from a condenser into this coil, Hertz discovered that the spark caused when the current jumped the gap set up electrical vibrations that excited powerful currents in the other coil. These currents were noticeable, though the coils were a very considerable distance apart. Thus Hertz had found out how to send out electrical waves that would travel to a considerable distance.
What was the medium that carried these waves? This was the question that Hertz asked himself, and the answer was, the ether. We know that light will pass through a vacuum, and these electric waves would do likewise. It was evident that they did not pass through the air. The answer, as evolved by Hertz and approved by other scientists, is that they travel through the ether, a strange substance which pervades all space. Hertz discovered that light and his electrical waves traveled at the same speed, and so deduced that light consists of electrical vibrations in the ether.
With the knowledge that this all-pervading ether would carry electric waves at the speed of light, that the waves could be set up by the discharge of a spark across a spark-gap in a coil, and that they could be received in another coil in resonance with the first, the establishment of a practical wireless telegraph was not far away.
The Italian Youth who Dreamed Wonderful Dreams—His Studies—EarlyDetectors—Marconi Seeks an Efficient Detector—Devises New SendingMethods—The Wireless Telegraph Takes Form—Experimental Success.
With the nineteenth century approaching its close, man had discovered that the electric waves would travel through the ether; he had learned something of how to propagate those waves, and something of how to receive them. But no one had yet been able to combine these discoveries in practical form, to apply them to the task of carrying messages, to make the improvements necessary to make them available for use at considerable distances. Though many mature scientists had devoted themselves to the problem, it remained for a youth to solve it. The youth was Guglielmo Marconi, an Italian.
We have noticed that the telegraph, the cable, and the telephone were the work of those of the Anglo-Saxon race—Englishmen or Americans—so it came as a distinct surprise that an Italian youth should make the next great application of electricity to communication. But Anglo-Saxon blood flows in Marconi's veins. Though his father was an Italian, his mother was an Irishwoman. He was born at Villa Griffone near Bologna, Italy, on April 25, 1874. He studied in the schools of Bologna and of Florence, and early showed his interest in scientific affairs. From his mother he learned English, which he speaks as fluently as he does his native tongue. As a boy he was allowed to attend English schools for short periods, spending some time at Bedford and at Rugby.
One of his Italian teachers was Professor Righi, who had made a close study of the Hertzian waves, and who was himself making no small contributions to the advancement of the science. From him young Marconi learned of the work which had been accomplished, and of the apparatus which was then available. Marconi was a quiet boy—almost shy.
He did not display the aggressive energy so common with many promising youths. But though he was quiet, he was not slothful. He entered into his studies with a determination and an application that brought to him great results. He was a student and a thinker. Any scientific book or paper which came before him was eagerly devoured. It was this habit of careful and persistent study that made it possible for Marconi to accomplish such wonderful things at an early age.
Marconi had learned of the Hertzian waves. It occurred to him that by their aid wireless telegraphy might be accomplished. The boy saw the wonderful possibilities; he dreamed dreams of how these waves might carry messages from city to city, from ship to shore, and from continent to continent without wires. He realized his own youth and inexperience, and it seemed certain to him that many able scientists had had the same vision and must be struggling toward its attainment. For a year Marconi dreamed those dreams, studying the books and papers which would tell him more of these wonderful waves. Each week he expected the news that wireless telegraphy had been established, but the news never came. Finally he concluded that others, despite their greater opportunities, had not been so far-seeing as he had thought.
Marconi attacked the problem himself with the dogged persistence and the studious care so characteristic of him. He began his experiments upon his father's farm, the elder Marconi encouraging the youth and providing him with funds with which to purchase apparatus. He set up poles at the opposite sides of the garden and on them mounted the simple sending and receiving instruments which were then available, using plates of tin for his aerials. He set up a simple spark-gap, as had Hertz, and used a receiving device little more elaborate. A Morse telegraph-key was placed in circuit with the spark-gap. When the key was held down for a longer period a long spark passed between the brass knobs of the spark-gap and a dash was thus transmitted. When the key was depressed for a shorter period a dot in the Morse code was sent forth. After much work and adjustment Marconi was able to send a message across the garden. Others had accomplished this for similar distances, but they lacked Marconi's imagination and persistence, and failed to carry their experiments further. To the young Irish-Italian this was but a starting-point.
[Illustration: GUGLIELMO MARCONI
Photographed in the uniform of an officer in the Italian army]
Marconi quickly found that the receiver was the least effective part of the existing apparatus. The waves spread in all directions from the sending station and become feebler and feebler as the distance increases. To make wireless telegraphy effective over any considerable distance a highly efficient and extremely sensitive receiving device is necessary. Some special means of detecting the feeble currents was necessary. The coherer was the solution. As early as 1870 a Mr. S.A. Varley, an Englishman, had discovered that when he endeavored to send a current through a mass of carbon granules the tiny particles arranged themselves in order under the influence of the electric current, and offered a free path for the passage of the current. When shaken apart they again resisted the flow of current until it became powerful enough to cause them to again arrange themselves into a sort of bridge for its passage. Thus was the principle of the coherer discovered.
An Italian scientist, Professor Calzecchi-Onesti, carried these experiments still further. He used various substances in place of the carbon granules and showed that some of them will arrange themselves so as to allow the passage of a current under the influence of the spark setting up the Hertzian waves. Professor E. Branly, of the Catholic University of Paris, took up this work in 1890. He arranged metal filings in a small glass tube six inches long and arranged a tapper to disarrange the filings after they had been brought together under the influence of the spark.
With the Branly coherer as the basis Marconi sought to make improvements which would result in the detector he was seeking. For his powder he used nickel, mixed with a small proportion of fine silver filings. This he placed between silver plugs in a small glass tube. Platinum wires were connected to the silver plugs and brought out at the opposite ends of the tube. It required long study to determine just how to adjust the plugs between which the powder was loosely arranged. If the particles were pressed together too tightly they would not fall apart readily enough under the influence of the tapper. If too much space was allowed they would not cohere readily enough. Marconi also discovered that a larger proportion of silver in the powder and a smaller amount between the plugs increased the sensitiveness of the receiver. Yet he found it well not to have it too sensitive lest it cohere for every stray current and so give false signals.
Under the influence of the electric waves set up from the spark-gap those tiny particles so arranged themselves that they would readily carry a current between the plugs. By placing these plugs with their platinum terminals in circuit with a local battery the current from this local battery was given a passage through the coherer by the action of the electric waves coming through the ether. While these waves themselves were too feeble to operate a receiving mechanism, they were strong enough to arrange the particles of the sensitive metal in the tube in order, so that the current from the local battery could pass through them. This current operated a telegraph relay which in turn operated a Morse receiving instrument. An electrical tapper was also arranged in this circuit so that it would strike the tube a light blow after each long or short wave representing a dot or a dash had been received. Thus the particles were disarranged, ready to array themselves when the next wave came through the ether and so form the bridge over which the stronger local circuit could convey the signal.
Marconi further discovered that the most effective arrangement was to run a wire from one terminal of the coherer into the ground, and from the other to an elevated metal plate or wire. The waves coming through the ether were received by the elevated wire and were conducted down to the coherer. Experimenting with his apparatus on the posts in the garden, he discovered that an increase in the height of the wire greatly increased the receiving distance.
At his sending station he used the exciter of his teacher, Professor Righi. This, too, he modified and perfected for his practical purpose. As he used the device it consisted of two brass spheres a millimeter apart. An envelope was provided so that the sides of the spheres toward each other and the space between was occupied by vaseline oil which served to keep the faces of the spheres clean and produce a more uniform spark. Outside the two spheres, but in line with them, were placed two smaller spheres at a distance of about two-fifths of a centimeter. The terminals of the sending circuit were attached to these. The secondary coil of a large induction coil was placed in series with them, and batteries were wired in series with the primary of the coil with a sending key to make and break the circuit. When the key was closed a series of sparks sprang across the spark-gap, and the waves were thus set up in the ether and carried the message to the receiving station.
As in the case of his receiving station, Marconi found that results were much improved when he wired his sending apparatus so that one terminal was grounded and the other connected with an elevated wire or aerial, which is now called the antenna. By 1896 Marconi had brought this apparatus to a state of perfection where he could transmit messages to a distance of several miles. This Irish-Italian youth of twenty-two had mastered the problem which had baffled veteran scientists and was ready to place a new wonder at the service of the world.
The devices which Marconi thus assembled and put to practical use had been, in the hands of others, little more than scientific toys. Others had studied the Hertzian waves and the methods of sending and detecting them from a purely scientific viewpoint. Marconi had the vision to realize the practical possibilities, and, though little more than a boy, had assembled the whole into a workable system of communication. He richly deserves the laurels and the rewards as the inventor of the wireless telegraph.