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.



XV

TELEGRAPHING WITHOUT WIRES

The First Suggestion—Morse Sends Messages Through the Water—Trowbridge Telegraphs Through the Earth—Experiments of Preece and Heaviside in England—Edison Telegraphs from Moving Trains—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.



XVI

AN ITALIAN BOY'S WORK

The Italian Youth who Dreamed Wonderful Dreams—His Studies—Early Detectors—Marconi Seeks an Efficient Detector—Devises New Sending Methods—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.



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.



XVII

WIRELESS TELEGRAPHY ESTABLISHED

Marconi Goes to England—he Confounds the Skeptics—A Message to France Without Wires—The Attempt to Span the Ocean—Marconi in America Receives the First Message from Europe—Fame and Recognition Achieved.

The time had now come for Marconi to introduce himself and his discoveries to the attention of the world. He went to England, and on June 2, 1896, applied for a patent on his system of wireless telegraphy. Soon afterward his plans were submitted to the postal-telegraph authorities. Fortunately for Marconi and for the world, W.H. Preece was then in authority in this department. He himself had experimented with some little success with wireless messages. He was able enough to see the merit in Marconi's discoveries and generous enough to give him full recognition and every encouragement.

The apparatus was first set up in the General Post-office in London, another station being located on the roof but a hundred yards away. Though several walls intervened, the Hertzian waves traversed them without difficulty, and messages were sent and received. Stations were then set up on Salisbury Plain, some two miles apart, and communication was established between them.

Though the postal-telegraph authorities received Marconi's statements of his discoveries with open mind and put his apparatus to fair tests, the public at large was much less tolerant. The skepticism which met Morse and Bell faced Marconi. Men of science doubted his statements and scoffed at his claims. The Hertzian waves might be all right to operate scientific playthings, they thought, but they were far too uncertain to furnish a medium for carrying messages in any practical way. Then, as progress was made and Marconi began to prove his system, the inevitable jealousies arose. Experimenters who might have invented the wireless telegraph, but who did not, came forward to contest Marconi's claims and to seek to snatch his laurels from him.

The young inventor forged steadily ahead, studying and experimenting, devising improved apparatus, meeting the difficulties one by one as they arose. In most of his early experiments he had used a modification of the little tin boxes which had been set up in his father's garden as his original aerials. Having discovered that the height of the aerials increased the range of the stations, he covered a large kite with tin-foil and, sending it up with a wire, used this as an aerial. Balloons were similarly employed. He soon recognized, however, that a practical commercial system, which should be capable of sending and receiving messages day and night, regardless of the weather, could not be operated with kites or balloons. The height of masts was limited, so he sought to increase the range by increasing the electrical power of the current sending forth the sparks from the sending station. Here he was on the right path, and another long step forward had been taken.

In the fall of 1897 he set up a mast on the Isle of Wight, one hundred and twenty feet high. From the top of this was strung a single wire and a new series of experiments was begun. Marconi had spent the summer in Italy demonstrating his apparatus, and had established communication between a station on the shore and a war-ship of the Italian Navy equipped with his apparatus. He now secured a small steamer for his experiments from his station on the Isle of Wight and equipped it with a sixty-foot mast. Communication was maintained with the boat day after day, regardless of weather conditions. The distance at which communication could be maintained was steadily increased until communication was established with the mainland.

In July of 1898 the wireless demonstrated its utility as a conveyer of news. An enterprising Dublin newspaper desired to cover the Kingstown regatta with the aid of the wireless. In order to do this a land station was erected at Kingstown, and another on board a steamer which followed the yachts. A telephone wire connected the Kingstown station with the newspaper office, and as the messages came by wireless from the ship they were telephoned to Dublin and published in successive editions of the evening papers.

This feat attracted so much attention that Queen Victoria sought the aid of the wireless for her own necessities. Her son, the Prince of Wales, lay ill on his yacht, and the aged queen desired to keep in constant communication with him. Marconi accordingly placed one station on the prince's yacht and another at Osborne House, the queen's residence. Communication was readily maintained, and one hundred and fifty messages passed by wireless between the prince and the royal mother.

While the electric waves bearing the messages were found to pass through wood, stone, or earth, it was soon noticed in practical operation that when many buildings, or a hill, or any other solid object of size intervened between the stations the waves were greatly retarded and the messages seriously interfered with. When the apparatus was placed on board steel vessels it was found that any part of the vessel coming between the stations checked the communication. Marconi sought to avoid these difficulties by erecting high aerials at every point, so that the waves might pass through the clear air over solid obstructions.

Marconi's next effort was to connect France with England. He went to France to demonstrate his apparatus to the French Government and set up a station near Boulogne. The aerial was raised to a height of one hundred and fifty feet. Another station was erected near Folkestone on the English coast, across the Channel. A group of French officials gathered in the little station near Folkestone for the test, which was made on the 27th of March, 1899. Marconi sent the messages, which were received by the station on the French shore without difficulty. Other messages were received from France, and wireless communication between the nations was an accomplished fact.

The use of the wireless for ships and lighthouses sprang into favor, and wireless stations were established all around the British coasts so that ships equipped with wireless might keep in communication with the land. The British Admiralty quickly recognized the value of wireless telegraphy to war vessels. While field telegraphs and telephones had served the armies, the navies were still dependent upon primitive signals, since a wire cannot be strung from ship to ship nor from ship to shore. So the British battle-ships were equipped with wireless apparatus and a thorough test was made. A sham battle was held in which all of the orders were sent by wireless, and communication was constantly maintained both between the flag-ships and the vessels of their fleets and between the flag-ships and the shore. Marconi's invention had again proved itself.

The wireless early demonstrated its great value as a means of saving life at sea. Lightships off the English coast were equipped with the wireless and were thus enabled to warn ships of impending storms, and on several occasions the wireless was used to summon aid from the shore when ships were sinking because of accidents near the lightship.

Following the establishment of communication with France, Marconi increased the range of his apparatus until he was able to cover most of eastern Europe. In one of his demonstrations he sent messages to Italy. His ambition, however, was to send messages across the Atlantic, and he now attacked this stupendous task. On the coast of Cornwall, England, he began the construction of a station which should have sufficient power to send a message to America. Instead of using a single wire for his aerial, he erected many tall poles and strung a number of wires from pole to pole. The comparatively feeble batteries which had furnished the currents used in the earlier efforts were replaced with great power-driven dynamos, and converters were used instead of the induction coil. Thus was the great Poldhu station established.

Late in 1901 Marconi crossed to America to superintend the preparations there, and that he himself might be ready to receive the first message, should it prove possible to span the ocean. Signal Hill, near St. John's, Newfoundland was selected as the place for the American station. The expense of building a great aerial for the test was too great, and so dependence was had upon kites to send the wires aloft. For many days Marconi's assistants struggled with the great kites in an effort to get them aloft. At last they flew, carrying the wire to a great height. The wire was carried into a small Government building near by in which Marconi stationed himself. At his ear was a telephone receiver, this having been substituted for the relay and the Morse instrument because of its far greater sensitiveness.

Marconi had instructed his operator at Poldhu to send simply the letter "s" at an hour corresponding to 12.30 A.M. in Newfoundland. Great was the excitement and suspense in Cornwall when the hour for the test arrived. Forgetting that they were sleepy, the staff crowded about the sending key, and the little building at the foot of the ring of great masts supporting the aerial shook with the crash of the blinding sparks as the three, dots which form the letter "s" were sent forth. Even greater was the tension on the Newfoundland coast, where Marconi sat eagerly waiting for the signal. Finally it came, three faint ticks in the telephone receiver. The wireless had crossed the Atlantic. Marconi had no sending apparatus, so that it was not until the cable had carried the news that those in England knew that the message had been received.

Because Marconi had never made a statement or a claim he had not been able to prove, he had attained a reputation for veracity which made his statement that he had received a signal across the Atlantic carry weight with the scientists. Many, of course, were skeptical, and insisted that the simple signal had come by chance from some ship not far away. But the inventor pushed quietly and steadily ahead, making arrangements to perfect the system and establish it so that it would be of commercial use.

Marconi returned to England, but two months later set out for America again on the liner Philadelphia with improved apparatus. He kept in constant communication with his station at Poldhu until the ship was a hundred and fifty miles from shore. Beyond that point he could not send messages, as the sending apparatus on the ship lacked sufficient power. Messages were received, however, until the sending station was over two thousand miles away. This seemed miraculous to those on shipboard, but Marconi accepted it as a matter of course. He had equipped the Poldhu station to send twenty-one hundred miles, and he knew that it should accomplish the feat.

A large station was set up at Cape Breton, Nova Scotia, and regular communication was established between there and Poldhu. With the establishment of regular transatlantic communication the utility of Marconi's invention, even for work at great distances, was no longer open to question. By quiet, unassuming, conscientious work he had put another great carrier of messages at the service of the world, and he now reaped the fame and fortune which he so richly deserved.



XVIII

THE WIRELESS SERVES THE WORLD

Marconi Organized Wireless Telegraphy Commercially—The New Wonder at the Service of the World—Marine Disasters Prevented—The Extension of the Wireless on Shipboard—Improved Apparatus—The Wireless in the World War—The Boy and the Wireless.

With his clear understanding of the possibilities of his invention, Marconi was not long in establishing the wireless upon a commercial basis. He is a man of keen business judgment, and as he brought his invention forward and clearly demonstrated its worth at a time when commercial enterprise was alert he found no great difficulty in establishing his company. The first Marconi company was organized as early as 1897 under the name of the Wireless Telegraph and Signal Company, Limited. This was later displaced by the Marconi Telegraph Company, which operates a regular system of stations on a commercial basis, carrying messages in competition with the cable and telegraph companies. It also erects stations for other companies which are operated under the Marconi patents.

With the telegraph and the telephone so well established and serving the needs of ordinary communication on land, it was natural that the wireless should make headway but slowly as a commercial proposition between points on land. For communication at sea, however, it had no competition, and merchant-ships as well as war vessels were rapidly equipped with wireless apparatus.

When the great liner Republic was sinking as a result of a collision off the port of New York in 1903 her wireless brought aid. Her passengers and crew were taken off in safety, and what otherwise would have been a terrible disaster was avoided by the use of the wireless. The utility of the wireless was again brought sharply to the attention of the world. It was realized that a wireless set on a passenger-ship was necessary if the lives of the passengers were to be safeguarded. The United States Government by its laws now requires that passenger-ships shall be equipped with wireless apparatus in charge of a competent operator.

One of the early objections made to the wireless was its apparent lack of secrecy, since any other receiving apparatus within range of the waves sent forth by the sending station can receive the signals. It was also realized that as soon as any considerable number of stations were established about the world, and began sending messages to and fro, there would be a perfect jumble of waves flying about in all directions through the ether, so that no messages could be sent or received.

Marconi's answer to these difficulties was the tuning apparatus. The electric waves carrying the messages may be sent out at widely varying lengths. Marconi found that it was possible to adjust a receiving station so that it would receive only waves of a certain length. Thus stations which desired to communicate could select a certain wave-length, and they could send and receive messages without interfering with others using different wave-lengths, or without the receiving station being confused by messages coming in from other stations using different wave-lengths. You know that when a tuning-fork is set in vibration another of the same pitch near it will vibrate with it, but others of different pitch will not be affected. The operation of wireless stations in tune with each other is similar.



An example of the value of tuning is afforded by the manner in which press reports are sent from the great Marconi station at Poldhu. Each night at a certain hour this station sends out news reports of the events of the day, using a certain set wave-length. Each ship on the Atlantic and every land station within range which is to receive the reports at that hour adjusts its receiving set to receive waves of that length. In this way they hear nothing but the Poldhu news reports which they desire to receive, and are not troubled by messages from other stations within range.

Secrecy is also attained by the use of tuning. It is possible that another station may discover the wave-length being used for a secret message and "listen in," but there are so many possible wave-lengths that this is difficult. Secrecy may also be secured by the use of code messages.

Many of the advantages of tuning were lost by the international agreement which provided that but two wave-lengths should be used for commercial work. This, however, enables ships to get in touch with other ships in time of need. With his telephone receivers the operator can hear the passage of the waves as they are brought to him by his aerial and the dots and dashes sound as buzzes of greater or less length. Out of the confusion of currents passing through the air he can select the messages he wishes to read by sound.

You may wonder how one wireless operator gets into communication with another. He first listens in to determine whether messages are coming through the ether within range in the wave-length he is to use. Hearing nothing, he adjusts his sending apparatus to the desired wave-length and switches this in with the signal aerial which serves both his sending and his receiving set. This at the same time disconnects his receiving set. He sends out the call letters of the station to which he wishes to send a message, following them with his own call letters, as a signature to show who is calling. After repeating these signals several times he switches out his sending set and listens in with his receiving set. If he then gets an answer from the other station he can begin sending the message.

Marconi was not allowed to hold the wireless field unmolested. Many others set up wireless stations, some of them infringing upon Marconi's patents. Others have devised wireless systems along more original lines. Particularly we should mention two American experimenters, Dr. de Forest and Professor Fessenden. Both have established wireless systems with no little promise. The system of Professor Fessenden is especially unique and original and may be destined to work a revolution in the methods of wireless telegraphy.

With an increase in the number of wireless stations and varieties of apparatus came a wide increase in the uses to which wireless telegraphy was applied. We have already noticed the press service from Poldhu. The British Government makes use of this same station to furnish daily news to its representatives in all parts of the world. The wireless is also used to transmit the time from the great observatories.

Some of the railroads in the United States have equipped their trails as well as their stations with wireless sets. It has proved its worth in communicating between stations, taking the place in time of need of either the telegraph or the telephone. In equipping the trains with sets a difficulty was met in arranging the aerials. It is, of course, impossible to arrange the wires at any height above the cars, since they would be swept away in passing under bridges. Even with very low aerials, however, communication has been successfully maintained at a distance of over a hundred miles. The speed of the fastest train affects the sending and receiving of messages not at all. It was also found that messages passed without hindrance, even though the train was passing through a tunnel.

Another interesting application of wireless telegraphy is to the needs of the fire-fighters. Fire stations in New York City have been equipped with wireless telegraph sets, and they have proved so useful in spreading alarms and transmitting news of fires that they seem destined to come into universal use.

The outbreak of the world war gave a tremendous impetus to the development of wireless telegraphy. The German cable to the United States was cut in the early days of the conflict. The sending power of wireless stations had been sufficiently increased, however, so that the great German stations could communicate with those in the United States. Communication was readily maintained between the Allies by means of wireless, the great stations at Poldhu and at the Eiffel Tower in Paris being in constant communication with each other and with the stations in Italy and in Russia.

Portable field sets had been used with some slight success even in the Boer War, and had definitely proved their worth in the Balkans. The outbreak of the greater war found all of the nations equipped with portable apparatus for the use of their armies. These proved of great use. The field sets of the United States Army also proved their utility in the campaign into Mexico in pursuit of Villa. By their means it was possible for General Pershing's forces to keep in constant touch with the headquarters in the United States.

The wireless proved as valuable to the navies as had been anticipated. The Germans in particular made great improvements in light wireless sets designed for use on aircraft. The problem of placing an aerial on an aeroplane is difficult, but no little headway has been made in this direction.

It is the American boy who has done the most interesting work with the wireless in the United States. While the commercial development has been comparatively slow, the boys have set up stations by the thousands. Most of these stations were constructed by the boys themselves, who have learned and are learning how best to apply this modern wonder to the service of man. So many amateurs set up stations that the Government found it necessary to regulate them by law. The law now requires that amateur experimenters use only short wave-lengths in their sending, which will not interfere with messages from Government or commercial stations. It also provides for the licensing of amateurs who prove competent.

The stations owned and operated by boys have already proved of great use. In times of storm and flood when wire communication failed they have proved the only means of communicating with many districts. In time of war these amateur stations, scattered in all parts of the country, might prove immensely valuable. Means have now been taken to so organize the amateurs that they can communicate with one another, and by this means messages may be sent to any part of the country.

One young American, John Hays Hammond, Jr., has applied the wireless in novel and interesting ways. By means of special apparatus mounted on a small boat he can by the means of a wireless station on shore start or stop the vessel, or steer it in any direction by his wireless control. He has applied the same system to the control of torpedoes. By this means a torpedo may be controlled after it has left the shore and may be directed in any direction as long as it is within sight. This invention may prove of incalculable benefit should America be attacked by a foreign power.

What startling developments of wireless telegraphy lie still in the future we do not know. Marconi has predicted that wireless messages will circle the globe. "I believe," he has said, "that in the near future a wireless message will be sent from New York completely around the world without relaying, and will be received by an instrument in the same office with the transmitter, in perhaps less time than Shakespeare's forty minutes."

Not long ago the United States battle-ship Wyoming, lying off Cape Henry on the Atlantic coast, communicated with the San Diego at Guaymas, on the Pacific coast of Mexico. This distance, twenty-five hundred miles across land, shows that Marconi's prediction may be realized in the not distant future.



XIX

SPEAKING ACROSS THE CONTINENT

A New "Hello Boy" in Boston—Why the Boy Sought the Job—The Useful Things the Boy Found to Do—Young Carty and the Multiple Switchboard—Called to New York City—He Quiets the Roaring Wires—Carty Made Engineer-in-Chief—Extending the Range of the Human Voice—New York Talks to San Francisco Over a Wire.

It seemed to many that the wireless telegraph was to be the final word in the development of communication, but two striking achievements coming in 1915 proved this to be far from the case. While one group of scientists had given themselves to experimentation with the Hertzian waves which led to wireless telegraphy, other scientists and engineers were busily engaged in bringing the telephone to a perfection which would enable it to accomplish even more striking feats. These electrical pioneers did not work as individuals, but were grouped together as the engineering staff of the American Telephone and Telegraph Company. At their head was John J. Carty, and it was under his guiding genius that the great work was accomplished. John Carty is the American son of Irish parents. He was born in Cambridge, Massachusetts, on April 14, 1861. His father was a gun-maker and an expert mechanic of marked intelligence and ingenuity who numbered among his friends Howe, the creator of the sewing-machine. As a boy John Carty displayed the liveliest interest in things electrical. When the time came for him to go to school, physics was his favorite study. He showed himself to be possessed of a keen mind and an infinite capacity for work. To these advantages was added a good elementary education. He was graduated from Cambridge Latin School, where he prepared for Harvard University. Before he could enter the university his eyesight failed, and the doctor forbade continuance of study. Many a boy would have been discouraged by this physical handicap which denied him complete scholastic preparation. But this boy was not the kind that gives up. He had been supplementing his school work in physics with experimentations upon his own behalf. Let us let Mr. Carty tell in his own words how he next occupied himself.

I had often visited the shop of Thomas Hall, at 19 Bromfield Street, and looked in the window. I went in from time to time, not to make large purchases, but mostly to make inquiries and to buy some blue vitriol, wire, or something of the kind. It was a store where apparatus was sold for experimentation in schools, and on Saturdays a number of Harvard and Institute of Technology professors could be found there. It was quite a rendezvous for the scientific men in those days, just the same as the Old Corner Bookstore at the corner of School and Washington Streets was a place where the literary men used to congregate. Don't think that I was an associate of these great scientists, but I was very much attracted to the atmosphere of that store. I wanted to get in and handle the apparatus.

Finally it occurred to me that I would like to get into the business, somehow. But I did not have the courage to go in and ask them for a job. One day I was going by and saw a sign hanging out, "Boy Wanted." I was about nineteen, and really thought I was something of a scientist, not exactly a boy. I was a boy, however. I walked by on one side of the street and then on the other, looking in, and finally the idea possessed me to go in and strike for that job. So I took down the sign, which was outside the window, put it under my arm, and went in and persuaded Tom Hall that I was the boy he wanted.

He said, "When can you begin?" I said, "Now." There was no talk of wages or duties. He said, "Take this package around to Earle & Prew's express and hurry back, as I have another errand for you to do." So I had to take a great, heavy box around to the express-office and get a receipt for it. I found, when Saturday night came around, that I had been engaged at the rate of fifty cents a day. I would have been glad to work for nothing.

Well, I did not get near that apparatus in a hurry, not until the time came for fixing up the window. My first talk in regard to it had no reference to services in a scientific capacity on my part. I had rather hoped that the boss would come around and consult with, me as to how to adjust the apparatus. But that was not it. He said: "John, clean out that window. Everything is full of dust, and be careful and don't break anything!" So I cleaned it out. I swept out the place, cleaned about there, did errands, mixed battery solutions, and got a great deal of experience there in one way or another. I did whatever there was to do and got a good deal of fun out of it, while becoming acquainted with the state of the art of that day. I got to know intimately all the different sorts of philosophical apparatus there were, and how to mix the various battery solutions. In fact, I became really quite experienced for those times in such matters.

It was not long before young Carty lost his job. Being a regular boy, he had been guilty of too much skylarking. This experience steadied him, and he forthwith sought a new job. He had met some of the employees of the telephone company and was naturally interested in their work. At that time "hello boys" held sway in the crude telephone exchanges, the "hello girl" having not yet appeared. So John Carty at the age of nineteen went to work in the Boston telephone exchange.

The switchboard at which they placed him had been good enough for the other boys who had been called upon to operate it, and indeed it represented the best thought and effort of the leaders in the telephone world. But it did not satisfy Carty, who, not content with simply-operating the board, studied its construction and began planning improvements. As Mr. Carty himself puts it:

The little switchboards of that day were a good deal like the automobiles of some years ago—one was likely to spend more time under the switchboard than, sitting at it! In that way I learned a great deal about the arrangement and construction of switchboards. Encountering the trouble first, I had an advantage over others in being able to suggest a remedy. So I have always thought it was a good thing to have troubles, as long as they are not too serious or too numerous. Troubles are certainly a great advantage, if we manage them correctly.

Certainly Carty made these switchboard troubles the first stepping-stone in his climb to the top in the field of telephone engineering. The improvements which the youngster suggested were so valuable that they were soon being made under his direction, and ere long he installed in the Boston exchange the first multiple switchboard, the fundamental features of which are in the switchboards of to-day. In his work with the switchboards young Carty early got in touch with Charles E. Scribner, another youngster who was doing notable work in this field. The young men became fast friends and worked much together. Scribner devoted himself almost exclusively to switchboards and came to be known as the father of the modern switchboard.

Boston had her peculiar problems and an "express" service was needed. How to handle this in the exchange was another problem, and this, too, Carty solved. For this purpose he designed and installed the first metallic circuit, multiple switchboard to go into service. The problems of the exchange were among the most serious of the many which troubled the early telephone companies. Of course every telephone-user desired to be able to converse with any other who had a telephone in his office or residence. The development of the switchboards had been comparatively slow in the past, and the service rendered by the boys proved far from satisfactory. The average boy proved himself too little amenable to discipline, too inclined to "sass" the telephone-users, and too careless. But the early use of "hello boys" was at least a success for the telephone in that it brought to its service John J. Carty. This boy pointed the way to the great improvements that made it possible to handle the constantly growing volume of calls expeditiously and effectively.

The early telephones were operated with a single wire grounded at either end, the earth return being used to complete the circuit as with the telegraph. But while the currents used to operate the telegraph are fairly strong and so can dominate the earth currents, the tiny currents which represented the vibrations of the human voice were all too often drowned by the earth currents which strayed on to the lines. Telephone engineers were not then agreed that this caused the difficulty; but they did know there was difficulty. Many weird noises played over the lines and as often as not the spoken word was twisted into the strangest gibberish and rendered unintelligible. If the telephone was to satisfy its patrons and prove of real service to the world, the difficulty had to be overcome. Some of the more progressive engineers insisted that a double-wire system without a ground was necessary. This, of course, involved tremendous expenses in rebuilding every line and duplicating every wire. The more conservative hesitated, but Carty forged ahead.

In 1880 he was engaged in operating a new line out of Boston. He was convinced that the double-wire system alone could be successful, and he arranged to operate a line on this plan. Taking two single lines, he instructed the operator at the other end to join them, forming a two-wire circuit. The results justified him. At last a line had been attained which could be depended upon to carry the conversation.

No sooner was one problem solved than another presented itself. What to do with the constantly increasing number of wires was a pressing difficulty. All telephone circuits had been strung overhead, and with the demand for telephones for office and residence rapidly increasing, the streets of the great cities were becoming a perfect forest of telephone poles, with the sky obscured by a maze of wires. Poles were constantly increased in height until a line was strung along Wall Street in New York City at a height of ninety feet. From the poles the wires overflowed to the housetops, increasing the difficulty of the engineers. How to protect the wires so that they could be placed underground was the problem.

We have noticed that Theodore Vail had been brought to the head of the Bell system in its infancy and had led the fight against the rival companies until it was thoroughly established. Now he was directing his genius and executive ability to so improving the telephone that it should serve every need of communication. While the engineers discussed theories Vail began actual tests. A trench five miles long was dug beside a railway track by the simple expedient of hitching a plow to a locomotive. In this trench were laid a number of wires, each with a different covering. The gutta-percha and the rubber coverings which had been used in cable construction predominated. It was found that these wires would carry the telephone currents, not as well as might be desired, but well enough to assure Vail that he was on the right track. The companies began to place their wires underground, and Vail saw to it that the experiments with coverings for telephone wires were continued. The result was the successful underground cables in use to-day.

At the same time Vail and his engineers were seeking to improve the wires themselves. Iron and steel wires had been used, but they proved unsatisfactory, as they rusted and were poor conductors. Copper was an excellent conductor, but the metal in the pure state is soft and no one then knew how to make a copper wire that would sustain its own weight. But Vail kept his men at the problem and the hard-drawn copper wire was at length evolved. This proved just what was needed for the telephone circuits. The copper wire was four times as expensive as the iron, but as it was four times as good Vail adopted it.

John Carty had rather more than kept pace with these improvements. He was but twenty-six years of age when Union N. Bethell, head of the New York company, picked Carty to take charge of the telephone engineering work in the metropolis. Bethell was Vail's chief executive officer, and under him Carty received an invaluable training in executive work. Carty's largest task was putting the wires underground, and here again he was a tremendous success. He found ways to make cables cheaper and better, and devised means of laying them at half the former cost. Having solved the most pressing problems in this field, his employers, who had come to recognize his marked genius, set him to work again on the switchboard. He was placed in charge of the switchboard department of the Western Electric Company, the concern which manufactures the apparatus for the telephone company. The switchboard, as we have seen, was Carty's first love, and again he pointed the way to great improvements. Most of the large switchboards of that time were installed under his direction, and they were better switchboards than had ever been known before.

Up to this time it had been thought necessary to have individual batteries supplying current to each line. These were a constant source of difficulty, and Carty directed his own attention, and that of his associate engineers, to finding a satisfactory solution. He sought a method of utilizing one common battery at the central station and the way was found and the improvement accomplished.

Though the telephone circuits were now protected from the earth, telephone-users, at times when the lines were busy, were still troubled with roarings and strange cross-talk. Though busy with the many engineering problems which the telephone heads had assigned to him, Carty found time for some original research. He showed that the roarings in the wires were largely caused by electro-static induction. In 1889 he read a paper before the Electric Club that startled the engineers of that day. He demonstrated that in every telephone circuit there is a particular point at which, if a telephone is inserted, no cross-talk can be heard. He had worked out the rules for determining this point. Thus he had at once discovered the trouble and prescribed the cure. Of course it could not be expected that the sage experts would all agree with young Carty right away; but they were forced to in the end, for again he was proved right.

By 1901 Carty was ready with another invention which was to place the telephone in the homes of hundreds of thousands who, without it, could scarcely have afforded this modern necessity. This was the "bridging bell" which made possible the party line. By its use four telephones could be placed on a single line, each with its own signal, so that any one could be rung without ringing the others. Its introduction inaugurated a new boom in the use of the telephone.

Theodore Vail had resigned from his positions with the telephone companies in 1890 with the determination to retire from business. But when the panic of 1907 came the directors of the company went to him on his Vermont farm and pleaded with him to return and again resume the leadership. Other and younger men would not do in this business crisis. They also pointed out that the nation's telephones had not yet been molded into the national system which had been his dream—a system of universal service in which any one at any point in the country might talk by telephone with any other. So Vail re-entered the telephone field and again took the presidency of the American Telephone and Telegraph Company.

One of his first official acts was to appoint John J. Carty his chief engineer. Vail had selected the right man to make his dreams come true; Carty now had the executive who would make it possible for him to accomplish even larger things. He set about building up the engineering organization which was to accomplish the work, selecting the most brilliant graduates of American technical schools. He set this organization to work upon the extension and development of the long-distance telephone lines.

As a "hello boy" Carty had believed in the possibility of the long-distance telephone when others had scoffed. He has told of an early experience while in the Boston exchange:

One hot day an old lady toiled up the inevitable flights of stairs which led to the telephone-office of those times. Out of breath, she sat down, and when she had recovered sufficiently to speak she said she wanted to talk to Chicago. My colleagues of that time were all what the ethnologists would rank a little bit lower than the wild Indian. These youngsters set up a great laugh; and, indeed, the absurdity of the old lady's project could hardly be overstated, because at that time Salem was a long-distance line, Lowell sometimes worked, and Worcester was the limit—that is, in every sense of the word. The Lowell line was so unreliable that we had a telegraph operator there, and when the talk was not possible, he pushed the message through by Morse. It is no wonder that the absurdity of the old lady's proposal was the cause of poorly suppressed merriment. But I can remember that I explained to her that our wires had not yet been extended to Chicago, and that, after she had departed, I turned to the other operators and said that the day would come when we could talk to Chicago. My prophecy was received with what might be called—putting it mildly—vociferous discourtesy. Nevertheless, I remember very well the impression which that old lady's request made upon me; and I really did believe that, some day or other, in some way, we would be able to talk to Chicago.

By 1912 it was possible to talk from New York to Denver, a distance of 2,100 miles. No European engineers had achieved any such results, and this feat brought to Carty and his wonderful staff the admiration of foreign experts. But for the American engineers this was only a starting-point.

The next step was to link New York and California. This was more than a matter of setting poles and stringing wires, stupendous though this task was. The line crosses thirteen States, and is carried on 130,000 poles. Three thousand tons of wire are used in the line. The Panama Canal took nine years to complete, and cost over three hundred million dollars; but within that time the telephone company spent twice that amount in engineering construction work alone, extending the scope of the telephone.

The technical problems were even more difficult. Carty and his engineers had to find a way to send something three thousand miles with the breath as its motive power. It was a problem of the conservation of the tiny electric current which carried the speech. The power could not be augmented or speech would not result at the destination.

Added to the efforts of these able engineers was the work of Prof. Michael I. Pupin, of Columbia University, whose brilliant invention of the loading coil some ten years before had startled the scientific world and had increased the range of telephonic transmission through underground cables and through overhead wires far beyond what had formerly been possible. Professor Pupin applied his masterful knowledge of physics and his profound mathematical attainments so successfully to the practical problems of the transmission of telephone speech that he has been called "the telephone scientist." It is impossible to talk over long-distance lines anywhere in America without speaking through Pupin coils, which are distributed throughout the hundreds of thousands of miles of wire covering the North American continent. In the transcontinental telephone line Pupin coils play a most important part, and they are distributed at eight-mile intervals throughout its entire length from the Atlantic to the Pacific. In speaking at a dinner of eminent scientists, Mr. Carty once said that on account of his distinguished scientific attainments and wonderful telephonic inventions, Professor Pupin would rank in history alongside of Bell himself.

We have seen how Alexander Graham Bell, standing in the little room in Boston, spoke through the crude telephone he had constructed the first words ever carried over a wire, and how these words were heard and understood by his associate, Thomas Watson. This was in 1876, and it was in January of 1915—less than forty years later—that these two men talked across the continent. The transcontinental line was complete. Bell in the offices of the company in New York talked freely with Watson in San Francisco, and all in the most conversational tone, without a trace of the difficulty that had attended their first conversation over the short line. Thus, within the span of a single life the telephone had been developed from a crude instrument which transmitted speech with difficulty over a wire a hundred feet long, until one could be heard perfectly, though over three thousand miles of wire intervened.

The spoken word travels across the continent almost instantaneously, far faster than the speed of sound. If it were possible for one to be heard in San Francisco as he shouted from New York through the air, four hours would be required before the sound would arrive. Thus the telephone has been brought to a point of perfection where it carries sound by electricity and reproduces it again far more rapidly and efficiently than sound can be transmitted through its natural medium.



XX

TELEPHONING THROUGH SPACE

The Search for the Wireless Telephone—Early Successes—Carty and His Assistants Seek the Wireless Telephone—The Task Before Them—De Forest's Amplifier—Experimental Success Achieved—The Test—Honolulu and Paris Hear Arlington—The Future.

No sooner had Marconi placed the wireless telegraph at the service of the world than men of science of all nations began the search for the wireless telephone. But the vibrations necessary to reproduce the sound of the human voice are so infinitely more complex than those which will suffice to carry signals representing the dots and dashes of the telegraph code that the problem long defied solution. Scientists attacked the problem with vigor, and various means of wireless telephony were developed, without any being produced which were effective over sufficient ranges to make them really useful.

Probably the earliest medium chosen to carry wireless speech was light rays. A microphone transmitter was arranged so that the vibrations of the voice would affect the stream of gas flowing in a sensitive burner. The flame was thus thrown into vibrations corresponding to the vibrations of sound. The rays from this flame were then directed by mirrors to a distant receiving station and there concentrated on a photo-electric selenium cell, which has the strange property of varying its resistance according to the illumination. Thus a telephone receiver arranged in series with it was made to reproduce the sounds.

This strange, wireless telephone was so arranged that a search-light beam could be used for the light path, and distances up to three miles were covered. Even with this limited range the search-light telephone had certain advantages. Its message could be received only by those in the direct line of the light. Neither did it require aerial masts or wires and a trained telegrapher who could send and receive the telegraph code. It was put to some use between battle-ships and smaller craft lying within a radius of a few miles. The sensitive selenium cell proved unreliable, however, and this means of communication was destined to failure.

The experimenters realized that future success lay in making the ether carry telephonic currents as it carried telegraphic currents. They succeeded in establishing communication without wires, using the same antenna as in wireless telegraphy, and the principles determined are those used in the wireless telephone of to-day. The sending apparatus was so arranged that continuous oscillations are set up in the ether, either by a high-frequency machine or from an electric arc. Where set up by spark discharges the spark frequency must be above twenty thousand per second. This unbroken wave train does not affect the telephone and is not audible in a telephone receiver inserted in the radio receiving circuit. But when a microphone transmitter is inserted in the sending circuit, instead of the make-and-break key used for telegraphy, the waves of the voice, thrown against the transmitter in speaking, break up the waves so that the telephone receiver in the receiving circuit will reproduce sound. Here was and is the wireless telephone. Marconi and many other scientists were able to operate it successfully over comparatively short distances, and were busily engaged in extending its range and improving the apparatus. One great difficulty involved was in increasing the power of the sending apparatus. Greater range has been secured in wireless telegraphy by using stronger sending currents. But the delicate microphone would not carry these stronger currents. Increased sensitiveness in the receiving apparatus was also necessary.

Not content with their accomplishments in increasing the scope of the wire telephone, the engineers of the Bell organization, headed by John J. Carty, turned their attention to the wireless transmission of speech. Determined that the existing telephone system should be extended and supplemented in every useful way, they attacked the problem with vigor. It was a problem that had long baffled the keenest of European scientists, including Marconi himself, but that did not deter Carty and his associates. They were determined that the glory of spanning the Atlantic by wireless telephone should come to America and American engineers. They wanted history to record the wireless telephone as an American achievement along with the telegraph and the telephone.

The methods used in achieving the wireless telephone were widely different from those which brought forth the telegraph and the telephone. Times had changed. Men had found that it was more effective to work together through organizations than to struggle along as individuals. The very physical scope of the undertakings made the old methods impracticable. One cannot perfect a transcontinental telephone line nor a transatlantic wireless telephone in a garret. And with a powerful organization behind them it was not necessary for Carty and his associates to starve and skimp through interminable years, handicapped by the inadequate equipment, while they slowly achieved results. This great organization, working with modern methods, produced the most wonderful results with startling rapidity.

Important work had already been done by Marconi, Fessenden, De Forest, and others. But their results were still incomplete; they could not talk for any considerable distance. Carty organized his staff with care, Bancroft Gerhardi, Doctor Jewett, H.D. Arnold, and Colpitts being prominent among the group of brilliant American scientists who joined with Carty in his great undertaking. While much had been accomplished, much still remained to be done, and the various contributions had to be co-ordinated into a unified, workable whole. In large part it was Carty's task to direct the work of this staff and to see that all moved smoothly and in the right direction. Just as the telephone was more complex than the telegraph, and the wireless telegraph than the telephone, so the apparatus used in wireless telephony is even more complex and technical. Working with the intricate mechanisms and delicate apparatus, one part after another was improved and adapted to the task at hand.

To the devices of Carty and his associates was added the extremely delicate detector that was needed. This was the invention of Dr. Lee de Forest, an American inventor and a graduate of the Sheffield Technical School of Yale University. De Forest's contribution was a lamp instrument, a three-step audion amplifier. This is to the wireless telephone what the coherer is to the wireless telegraph. It is so delicate that the faintest currents coming through the ether will stimulate it and serve to set in motion local sources of electrical energy so that the waves received are magnified to a point where they will produce sound.

By the spring of 1915, but a few months after the transcontinental telephone line had been put in operation, Carty had his wireless telephone apparatus ready for extended tests. A small experimental tower was set up at Montauk Point, Long Island, and another was borrowed at Wilmington, Delaware. The tests were successful, and the experimenters found that they could talk freely with each other. Soon they talked over a thousand miles, from the tower at Montauk Point to another at St. Simon's Island, Georgia. This in itself was a great achievement, but the world was not told of it. "Do it first and then talk about it" is the maxim with Theodore Vail and his telephone men. This was but a beginning, and Carty had far more wonderful things in mind.

It was on the 29th of September, 1915, that Carty conducted the demonstrations which thrilled the world and showed that wireless telephony was an accomplished fact. Sitting in his office in New York, President Theodore Vail spoke into his desk telephone of the familiar type. The wires carried his words to the towers of the Navy wireless station at Arlington, Virginia, where they were delivered to the sending apparatus of the wireless telephone. Leaping into space, they traveled in every direction through the ether. The antenna of the wireless station at Mare Island, California, caught part of the waves and they were amplified so that John Carty, sitting with his ear to the receiver, could hear the voice of his chief. Carty and his associates had not only developed a system which made it possible to talk across the continent without wires, but they had made it possible to combine wire and wireless telegraphy. He and Vail talked with each other freely and easily, while the naval officers who verified the tests marveled.

But even more wonderful things were to come. Early in the morning of the next day other messages were sent from the Arlington tower, and these messages were heard by Lloyd Espenschied, one of Carty's engineers, who was stationed at the wireless station at Pearl Harbor, near Honolulu, Hawaii. The distance covered was nearly five thousand miles, and half of it was across land, which is the more remarkable as the wireless does not operate so readily over land as over water. The distance covered in this test was greater than the distance from Washington to London, Paris, Berlin, Vienna, or Petrograd. The successful completion of this test meant that the capitals of the great nations of the world might communicate, might talk with one another, by wireless telephone. Only a receiving set had been installed at Hawaii, so that it was not possible for Espenschied to reply to the message from Arlington, and it was not until his message came by cable that those at Arlington knew that the words they had spoken had traveled five thousand miles. Other receiving sets had been located at San Diego and at Darien on the Isthmus of Panama, and at these points also the words were distinctly heard.

By the latter part of October all was in readiness for a transatlantic test, and on the 20th of October American engineers, with American apparatus installed at the great French station at the Eiffel Tower, Paris, heard the words spoken at Arlington, Virginia. Carty and his engineers had bridged the Atlantic for the spoken word. Because of war-time conditions it was not possible to secure the use of the French station for an extended test, but the fact was established that once the apparatus is in place telephonic communication between Europe and America may he carried on regularly.

The apparatus used as developed by the engineers of the Bell system was in a measure an outgrowth of their work with the long-distance telephone. Wireless telephony, despite the wonders it has already accomplished, is still in its infancy. With more perfect apparatus and the knowledge that comes with experience we may expect that speech will girdle the earth.

It is natural that one should wonder whether the wireless telephone is destined to displace our present apparatus. This does not seem at all probable. In the first place, wireless telephony is now, and probably always will be, very expensive. Where the wire will do it is the more economical. There are many limitations to the use of the other for talking purposes, and it cannot be drawn upon too strongly by the man of science. It will accomplish miracles, but must not be overtaxed. Millions of messages going in all directions, crossing and recrossing one another, as is done every day by wire, are probably an impossibility by wireless telephony. Weird and little-understood conditions of the ether, static electricity, radio disturbances, make wireless work uncertain, and such a thing as twenty-four-hour service, seven days in the week, can probably never be guaranteed. In radio communication all must use a common medium, and as its use increases, so also do the difficulties. The privacy of the wire is also lacking with the wireless telephone.

But because a way was found to couple the wireless telephone with the wire telephone, the new wonder has great possibilities as a supplement to our existing system. Before so very long it may be possible for an American business man sitting in his office to call up and converse with a friend on a liner crossing the Atlantic. The advantages of speaking between ship and ship as an improvement over wireless telegraphy in time of need are obvious. A demonstration of the part this great national telephone system would play in the country's defense in case of attack was held in May of 1916. The Navy Department at Washington was placed in communication with every navy-yard and post in the United States, so that the executive officers could instantly talk with those in charge of the posts throughout the country. The wireless telephone was used in addition to the long distance, and Secretary of the Navy Daniels, sitting at his desk at Washington, talked with Captain Chandler, who was at his station on the bridge of the U.S.S. New Hampshire at Hampton Roads.

Whatever the future limitations of wireless telephony, there is no doubt as to the place it will take among the scientific accomplishments of the age. Merely as a scientific discovery or invention, it ranks among the wonders of civilization. Much as the tremendous leap of human voice across the line from New York to San Francisco appealed to the mind, there is something infinitely more fascinating in this new triumph of the engineer. The human mind can grasp the idea of the spoken word being carried along wires, though that is difficult enough, but when we try to understand its flight through space we are faced with something beyond the comprehension of the layman and almost past belief.

We have seen how communication has developed, very slowly at first, and then, as electricity was discovered, with great rapidity until man may converse with man at a distance of five thousand miles. What the future will bring forth we do not know. The ether may be made to accomplish even more wonderful things as a bearer of intelligence. Though we cannot now see how it would be possible, the day may come when every automobile and aeroplane will be equipped with its wireless telephone, and the motorist and aviator, wherever they go, may talk with anyone anywhere. The transmission of power by wireless is confidently predicted. Pictures have been transmitted by telegraph. It may be possible to transmit them by wireless. Then some one may find out how to transmit moving pictures through the ether. Then one might sit and see before him on a screen a representation of what was then happening thousands of miles away, and, listening through a telephone, hear all the sounds at the same place. Wonders that we cannot even now imagine may lie before us.



APPENDIX A

NEW DEVELOPMENTS OF THE TELEGRAPH

By F.W. Lienan, Superintendent Tariff Bureau, Western Union Telegraph Company

The invention of Samuel F.B. Morse is unique in this, that the methods and instruments of telegraph operation as he evolved them from his first experimental apparatus were so simple, and yet so completely met the requirements, that they have continued in use to the present day in practically their original form. But this does not mean that there has not been the same constant striving for betterment in this as in every other art. Many minds have, since the birth of the telegraph, occupied themselves with the problem of devising improved means of telegraphic transmission. The results have varied according to the point of view from which the subject was approached, but all, directly or indirectly, sought the same goal (the obvious one, since speed is the essence of telegraphy), to find the best means of sending more messages over the wire in a given time. It will readily suggest itself that the solution of this problem lies either in an arrangement enabling the wire to carry more than one message at once, or in some apparatus capable of transmitting messages over the wire more rapidly than can be done by hand, or in a combination of both these principles.

Duplex and quadruples operations are perhaps the most generally known methods by which increased utilization of the capacity of the line has been achieved. Duplex operation permits of the sending of two messages over one wire in opposite directions at the same time; and quadruples, the simultaneous transmission of four messages, two going in each direction. Truly a remarkable accomplishment; but, like many other things that have found their permanent place in daily use, become so familiar that we no longer pause to marvel at it. These expedients constitute a direct and very effective attack on the problem how to get more work out of the wire with the existing means of operation, and on account of their fundamental character and the important place which by reason thereof they have taken in the telegraphic art, are entitled to first mention.

The problem of increasing the rapidity of transmission has been met by various automatic systems of telegraphy, so called because they embody the idea of mechanical transmission with resulting gain in speed and other advantages. The number of these which have from time to time been devised is considerable. Not all have proven to be practicable, but those which have failed to prove in under actual operating conditions none the less display evidence of ingenuity which may well excite our admiration.

To mention one or two which may be interesting on account of the oddity of their method—there was, for instance, an early device, similar in principle to the calling apparatus of the automatic telephone, which involved the turning of a movable disk so that a projection on its circumference pointed successively to the letters to be transmitted. Experiments were made with ordinary metal type set up in a composing-stick, a series of brushes passing over the type faces and producing similar characters on a tape at the other end of the line. In another more recent ingenious device a pivoted mirror at the receiving end was so manipulated by the electrical impulses that a ray of light reflected from the surface of the mirror actually wrote the message upon sensitized paper, like a pencil, in a fair handwriting. In another the receiving apparatus printed vertical, horizontal, and slanting lines in such manner that they combined to make letters, rather angular, it is true, but legible.

These and other kindred devices are interesting as efforts to accomplish the direct production of legible messages. In experimental tests they performed their function successfully, and in some cases with considerable speed, but some of them required more than one line wire, some were too sensitive to disturbance by inductive currents and some developed other weaknesses which have prevented their incorporation in the actual operating machinery of to-day.

In the general development of the so-called automatic telegraph devices which have been or now are in practical operation, two lines have been pursued. One involves direct keyboard transmission; the other, the use at the sending end of a perforated tape capable of being run through a transmitting machine at high speed. One type of the former is the so-called step-by-step process, in which a revolving body in the transmitting apparatus, as, for instance, a cylinder provided with pegs placed at intervals around its circumference in spiral fashion, is arrested by the depression of the keys of the keyboard in such a way that a type wheel in the receiving apparatus at the distant end of the line prints the corresponding letter. This method was employed in the House and Phelps printing telegraphs operated by the Western Union Telegraph Company in its earlier days, and is to-day used in the operation of the familiar ticker. In another type of direct keyboard operation the manipulation of the keys transmits the impulses directly to the line and the receiving apparatus translates them by electrically controlled mechanical devices into printed characters in message form.

The systems best adapted to rapid telegraph work are predicated on the use of a perforated tape on which, by means of a suitable perforating apparatus, little round holes are produced in various groupings, each group, when the tape is passed through the transmitter, causing a certain combination of electrical impulses to pass over the wire. The transmitter as a rule consists of a mechanically or motor driven mechanism which causes the telegraph impulses to be transmitted to the line, and the combination and character of the impulses are determined by the tape perforations. The rapidity with which the tape may be driven through the transmitter makes very high speed operation possible. Of course it is necessary that there should be at the other end of the wire apparatus capable of receiving and recording the signals as speedily as they are sent.

As early as 1848 Alexander Bain perfected a system involving the use of the perforated transmitting tape; at the receiving station the messages were recorded in dots and dashes upon a chemically prepared strip of paper by means of iron pens, the metal of which was, through the combined action of the electrical current and the chemical preparation, decomposed, producing black marks in the form of dots and dashes upon the paper. The Bain apparatus was in actual operation in the younger days of the telegraph. Various systems, based on similar principles, involving tape transmission and the production of dots and dashes on a receiving tape, have from time to time been devised, but have generally not succeeded in establishing any permanent usefulness in competition with more effective instrumentalities which have been perfected.

The hardiest survivor of them is the Wheatstone apparatus, which has been in successful operation for years. Originally the perforating—or, to use the commonly current term, the punching—of the Wheatstone sending tape was accomplished by a mechanism equipped with three keys—one for the dot, one for the dash, and one for the space. The keys were struck with rubber-tipped mallets held in the hands of the operator and brought down with considerable force. Later this rather primitive perforator was supplanted by one equipped with a full keyboard on the order of a typewriter keyboard. At the receiving end of the line the messages are produced on a tape in dots and dashes of the Morse alphabet, and hence a further process of translation is necessary. This system has proven very useful, particularly in times of wire trouble and scarcity of facilities, when it is essential to move as many messages as possible over the available lines.

The schemes devised for combining automatic transmission by the perforated-tape method with direct production of the message at its destination in ordinary letters and figures, eliminating the intervening step of translation from Morse characters, have been many. Their individual enumeration is beyond the scope of the present discussion, and would in any event involve a wearisome exposition of their distinguishing technical features. Several of these systems are at present in practical and very effective operation.

One of the forerunners of the printing telegraph systems now in use was the Buckingham system, for many years employed by the Western Union Telegraph Company, but now for some time obsolete. The receiving mechanism of this system printed the messages on telegraph blanks placed upon a cylinder of just the right circumference to accommodate two telegraph blanks. The blanks were arranged in pairs, rolled into the form of a tube and placed around the cylinder. When two messages had been written a new pair of blanks had to be substituted. This was a rather awkward arrangement, but at a time when more highly developed apparatus had not been perfected it served its purpose to good advantage.