Part 11
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.