VIII. AUTOMATIC, DUPLEX, AND QUADRUPLEX TELEGRAPHY…

VIII. AUTOMATIC, DUPLEX, AND QUADRUPLEX TELEGRAPHY

WORK of various kinds poured in upon the young manufacturer, busy also with his own schemes and inventions, which soon began to follow so many distinct lines of inquiry that it ceases to be easy or necessary for the historian to treat them all in chronological sequence. Some notion of his ceaseless activity may be formed from the fact that he started no fewer than three shops in Newark during 1870-71, and while directing these was also engaged by the men who controlled the Automatic Telegraph Company of New York, which had a circuit to Washington, to help it out of its difficulties. "Soon after starting the large shop (10 and 12 Ward Street, Newark), I rented shop-room to the inventor of a new rifle. I think it was the Berdan. In any event, it was a rifle which was subsequently adopted by the British Army. The inventor employed a tool-maker who was the finest and best tool-maker I had ever seen. I noticed that he worked pretty near the whole of the twenty-four hours. This kind of application I was looking for. He was getting $21.50 per week, and was also paid for overtime. I asked him if he could run the shop. 'I don't know; try me!' he said. 'All right, I will give you $60 per week to run both shifts.' He went at it. His executive ability was greater than that of any other man I have yet seen. His memory was prodigious, conversation laconic, and movements rapid. He doubled the production inside three months, without materially increasing the pay-roll, by increasing the cutting speeds of tools, and by the use of various devices. When in need of rest he would lie down on a work-bench, sleep twenty or thirty minutes, and wake up fresh. As this was just what I could do, I naturally conceived a great pride in having such a man in charge of my work. But almost everything has trouble connected with it. He disappeared one day, and although I sent men everywhere that it was likely he could be found, he was not discovered. After two weeks he came into the factory in a terrible condition as to clothes and face. He sat down and, turning to me, said: 'Edison, it's no use, this is the third time; I can't stand prosperity. Put my salary back and give me a job.' I was very sorry to learn that it was whiskey that spoiled such a career. I gave him an inferior job and kept him for a long time."

Edison had now entered definitely upon that career as an inventor which has left so deep an imprint on the records of the United States Patent Office, where from his first patent in 1869 up to the summer of 1910 no fewer than 1328 separate patents have been applied for in his name, averaging thirty-two every year, and one about every eleven days; with a substantially corresponding number issued. The height of this inventive activity was attained about 1882, in which year no fewer than 141 patents were applied for, and seventy-five granted to him, or nearly nine times as many as in 1876, when invention as a profession may be said to have been adopted by this prolific genius. It will be understood, of course, that even these figures do not represent the full measure of actual invention, as in every process and at every step there were many discoveries that were not brought to patent registration, but remained "trade secrets." And furthermore, that in practically every case the actual patented invention followed from one to a dozen or more gradually developing forms of the same idea.

An Englishman named George Little had brought over a system of automatic telegraphy which worked well on a short line, but was a failure when put upon the longer circuits for which automatic methods are best adapted. The general principle involved in automatic or rapid telegraphs, except the photographic ones, is that of preparing the message in advance, for dispatch, by perforating narrow strips of paper with holes--work which can be done either by hand-punches or by typewriter apparatus. A certain group of perforations corresponds to a Morse group of dots and dashes for a letter of the alphabet. When the tape thus made ready is run rapidly through a transmitting machine, electrical contact occurs wherever there is a perforation, permitting the current from the battery to flow into the line and thus transmit signals correspondingly. At the distant end these signals are received sometimes on an ink-writing recorder as dots and dashes, or even as typewriting letters; but in many of the earlier systems, like that of Bain, the record at the higher rates of speed was effected by chemical means, a tell-tale stain being made on the travelling strip of paper by every spurt of incoming current. Solutions of potassium iodide were frequently used for this purpose, giving a sharp, blue record, but fading away too rapidly.

The Little system had perforating apparatus operated by electromagnets; its transmitting machine was driven by a small electromagnetic motor; and the record was made by electrochemical decomposition, the writing member being a minute platinum roller instead of the more familiar iron stylus. Moreover, a special type of wire had been put up for the single circuit of two hundred and eighty miles between New York and Washington. This is believed to have been the first "compound" wire made for telegraphic or other signalling purposes, the object being to secure greater lightness with textile strength and high conductivity. It had a steel core, with a copper ribbon wound spirally around it, and tinned to the core wire. But the results obtained were poor, and in their necessity the parties in interest turned to Edison.

Mr. E. H. Johnson tells of the conditions: "Gen. W. J. Palmer and some New York associates had taken up the Little automatic system and had expended quite a sum in its development, when, thinking they had reduced it to practice, they got Tom Scott, of the Pennsylvania Railroad to send his superintendent of telegraph over to look into and report upon it. Of course he turned it down. The syndicate was appalled at this report, and in this extremity General Palmer thought of the man who had impressed him as knowing it all by the telling of telegraphic tales as a means of whiling away lonesome hours on the plains of Colorado, where they were associated in railroad-building. So this man--it was I--was sent for to come to New York and assuage their grief if possible. My report was that the system was sound fundamentally, that it contained the germ of a good thing, but needed working out. Associated with General Palmer was one Col. Josiah C. Reiff, then Eastern bond agent for the Kansas Pacific Railroad. The Colonel was always resourceful, and didn't fail in this case. He knew of a young fellow who was doing some good work for Marshall Lefferts, and who it was said was a genius at invention, and a very fiend for work. His name was Edison, and he had a shop out at Newark, New Jersey. He came and was put in my care for the purpose of a mutual exchange of ideas and for a report by me as to his competency in the matter. This was my introduction to Edison. He confirmed my views of the automatic system. He saw its possibilities, as well as the chief obstacles to be overcome--viz., the sluggishness of the wire, together with the need of mechanical betterment of the apparatus; and he agreed to take the job on one condition--namely, that Johnson would stay and help, as 'he was a man with ideas.' Mr. Johnson was accordingly given three months' leave from Colorado railroad-building, and has never seen Colorado since."

Applying himself to the difficulties with wonted energy, Edison devised new apparatus, and solved the problem to such an extent that he and his assistants succeeded in transmitting and recording one thousand words per minute between New York and Washington, and thirty-five hundred words per minute to Philadelphia. Ordinary manual transmission by key is not in excess of forty to fifty words a minute. Stated very briefly, Edison's principal contribution to the commercial development of the automatic was based on the observation that in a line of considerable length electrical impulses become enormously extended, or sluggish, due to a phenomenon known as self-induction, which with ordinary Morse work is in a measure corrected by condensers. But in the automatic the aim was to deal with impulses following each other from twenty-five to one hundred times as rapidly as in Morse lines, and to attempt to receive and record intelligibly such a lightning-like succession of signals would have seemed impossible. But Edison discovered that by utilizing a shunt around the receiving instrument, with a soft iron core, the self-induction would produce a momentary and instantaneous reversal of the current at the end of each impulse, and thereby give an absolutely sharp definition to each signal. This discovery did away entirely with sluggishness, and made it possible to secure high speeds over lines of comparatively great lengths. But Edison's work on the automatic did not stop with this basic suggestion, for he took up and perfected the mechanical construction of the instruments, as well as the perforators, and also suggested numerous electrosensitive chemicals for the receivers, so that the automatic telegraph, almost entirely by reason of his individual work, was placed on a plane of commercial practicability. The long line of patents secured by him in this art is an interesting exhibit of the development of a germ to a completed system, not, as is usually the case, by numerous inventors working over considerable periods of time, but by one man evolving the successive steps at a white heat of activity.

This system was put in commercial operation, but the company, now encouraged, was quite willing to allow Edison to work out his idea of an automatic that would print the message in bold Roman letters instead of in dots and dashes; with consequent gain in speed in delivery of the message after its receipt in the operating-room, it being obviously necessary in the case of any message received in Morse characters to copy it in script before delivery to the recipient. A large shop was rented in Newark, equipped with $25,000 worth of machinery, and Edison was given full charge. Here he built their original type of apparatus, as improved, and also pushed his experiments on the letter system so far that at a test, between New York and Philadelphia, three thousand words were sent in one minute and recorded in Roman type. Mr. D. N. Craig, one of the early organizers of the Associated Press, became interested in this company, whose president was Mr. George Harrington, formerly Assistant Secretary of the United States Treasury.

Mr. Craig brought with him at this time--the early seventies--from Milwaukee a Mr. Sholes, who had a wooden model of a machine to which had been given the then new and unfamiliar name of "typewriter." Craig was interested in the machine, and put the model in Edison's hands to perfect. "This typewriter proved a difficult thing," says Edison, "to make commercial. The alignment of the letters was awful. One letter would be one-sixteenth of an inch above the others; and all the letters wanted to wander out of line. I worked on it till the machine gave fair results. [3] Some were made and used in the office of the Automatic company. Craig was very sanguine that some day all business letters would be written on a typewriter. He died before that took place; but it gradually made its way. The typewriter I got into commercial shape is now known as the Remington. About this time I got an idea I could devise an apparatus by which four messages could simultaneously be sent over a single wire without interfering with each other. I now had five shops, and with experimenting on this new scheme I was pretty busy; at least I did not have ennui."

[Footnote 3: See illustration on opposite page, showing reproduction of the work done with this machine.]

A very interesting picture of Mr. Edison at this time is furnished by Mr. Patrick B. Delany, a well-known inventor in the field of automatic and multiplex telegraphy, who at that time was a chief operator of the Franklin Telegraph Company at Philadelphia. His remark about Edison that "his ingenuity inspired confidence, and wavering financiers stiffened up when it became known that he was to develop the automatic" is a noteworthy evidence of the manner in which the young inventor had already gained a firm footing. He continues: "Edward H. Johnson was brought on from the Denver & Rio Grande Railway to assist in the practical introduction of automatic telegraphy on a commercial basis, and about this time, in 1872, I joined the enterprise. Fairly good results were obtained between New York and Washington, and Edison, indifferent to theoretical difficulties, set out to prove high speeds between New York and Charleston, South Carolina, the compound wire being hitched up to one of the Southern & Atlantic wires from Washington to Charleston for the purpose of experimentation. Johnson and I went to the Charleston end to carry out Edison's plans, which were rapidly unfolded by telegraph every night from a loft on lower Broadway, New York. We could only get the wire after all business was cleared, usually about midnight, and for months, in the quiet hours, that wire was subjected to more electrical acrobatics than any other wire ever experienced. When the experiments ended, Edison's system was put into regular commercial operation between New York and Washington; and did fine work. If the single wire had not broken about every other day, the venture would have been a financial success; but moisture got in between the copper ribbon and the steel core, setting up galvanic action which made short work of the steel. The demonstration was, however, sufficiently successful to impel Jay Gould to contract to pay about $4,000,000 in stock for the patents. The contract was never completed so far as the $4,000,000 were concerned, but Gould made good use of it in getting control of the Western Union."

One of the most important persons connected with the automatic enterprise was Mr. George Harrington, to whom we have above referred, and with whom Mr. Edison entered into close confidential relations, so that the inventions made were held jointly, under a partnership deed covering "any inventions or improvements that may be useful or desired in automatic telegraphy." Mr. Harrington was assured at the outset by Edison that while the Little perforator would give on the average only seven or eight words per minute, which was not enough for commercial purposes, he could devise one giving fifty or sixty words, and that while the Little solution for the receiving tape cost $15 to $17 per gallon, he could furnish a ferric solution costing only five or six cents per gallon. In every respect Edison "made good," and in a short time the system was a success, "Mr. Little having withdrawn his obsolete perforator, his ineffective resistance, his costly chemical solution, to give place to Edison's perforator, Edison's resistance and devices, and Edison's solution costing a few cents per gallon. But," continues Mr. Harrington, in a memorable affidavit, "the inventive efforts of Mr. Edison were not confined to automatic telegraphy, nor did they cease with the opening of that line to Washington." They all led up to the quadruplex.

Flattered by their success, Messrs. Harrington and Reiff, who owned with Edison the foreign patents for the new automatic system, entered into an arrangement with the British postal telegraph authorities for a trial of the system in England, involving its probable adoption if successful. Edison was sent to England to make the demonstration, in 1873, reporting there to Col. George E. Gouraud, who had been an associate in the United States Treasury with Mr. Harrington, and was now connected with the new enterprise. With one small satchel of clothes, three large boxes of instruments, and a bright fellow-telegrapher named Jack Wright, he took voyage on the Jumping Java, as she was humorously known, of the Cunard line. The voyage was rough and the little Java justified her reputation by jumping all over the ocean. "At the table," says Edison, "there were never more than ten or twelve people. I wondered at the time how it could pay to run an ocean steamer with so few people; but when we got into calm water and could see the green fields, I was astounded to see the number of people who appeared. There were certainly two or three hundred. I learned afterward that they were mostly going to the Vienna Exposition. Only two days could I get on deck, and on one of these a gentleman had a bad scalp wound from being thrown against the iron wall of a small smoking-room erected over a freight hatch."

Arrived in London, Edison set up his apparatus at the Telegraph Street headquarters, and sent his companion to Liverpool with the instruments for that end. The condition of the test was that he was to send from Liverpool and receive in London, and to record at the rate of one thousand words per minute, five hundred words to be sent every half hour for six hours. Edison was given a wire and batteries to operate with, but a preliminary test soon showed that he was going to fail. Both wire and batteries were poor, and one of the men detailed by the authorities to watch the test remarked quietly, in a friendly way: "You are not going to have much show. They are going to give you an old Bridgewater Canal wire that is so poor we don't work it, and a lot of 'sand batteries' at Liverpool." [4] The situation was rather depressing to the young American thus encountering, for the first time, the stolid conservatism and opposition to change that characterizes so much of official life and methods in Europe. "I thanked him," says Edison, "and hoped to reciprocate somehow. I knew I was in a hole. I had been staying at a little hotel in Covent Garden called the Hummums! and got nothing but roast beef and flounders, and my imagination was getting into a coma. What I needed was pastry. That night I found a French pastry shop in High Holborn Street and filled up. My imagination got all right. Early in the morning I saw Gouraud, stated my case, and asked if he would stand for the purchase of a powerful battery to send to Liverpool. He said 'Yes.' I went immediately to Apps on the Strand and asked if he had a powerful battery. He said he hadn't; that all that he had was Tyndall's Royal Institution battery, which he supposed would not serve. I saw it--one hundred cells--and getting the price--one hundred guineas--hurried to Gouraud. He said 'Go ahead.' I telegraphed to the man in Liverpool. He came on, got the battery to Liverpool, set up and ready, just two hours before the test commenced. One of the principal things that made the system a success was that the line was put to earth at the sending end through a magnet, and the extra current from this, passed to the line, served to sharpen the recording waves. This new battery was strong enough to pass a powerful current through the magnet without materially diminishing the strength of the line current."

[Footnote 4: The sand battery is now obsolete. In this type, the cell containing the elements was filled with sand, which was kept moist with an electrolyte.]

The test under these more favorable circumstances was a success. "The record was as perfect as copper plate, and not a single remark was made in the 'time lost' column." Edison was now asked if he thought he could get a greater speed through submarine cables with this system than with the regular methods, and replied that he would like a chance to try it. For this purpose, twenty-two hundred miles of Brazilian cable then stored under water in tanks at the Greenwich works of the Telegraph Construction & Maintenance Company, near London, was placed at his disposal from 8 P.M. until 6 A.M. "This just suited me, as I preferred night-work. I got my apparatus down and set up, and then to get a preliminary idea of what the distortion of the signal would be, I sent a single dot, which should have been recorded upon my automatic paper by a mark about one-thirty-second of an inch long. Instead of that it was twenty-seven feet long! If I ever had any conceit, it vanished from my boots up. I worked on this cable more than two weeks, and the best I could do was two words per minute, which was only one-seventh of what the guaranteed speed of the cable should be when laid. What I did not know at the time was that a coiled cable, owing to induction, was infinitely worse than when laid out straight, and that my speed was as good as, if not better than, with the regular system; but no one told me this." While he was engaged on these tests Colonel Gouraud came down one night to visit him at the lonely works, spent a vigil with him, and toward morning wanted coffee. There was only one little inn near by, frequented by longshoremen and employees from the soap-works and cement-factories--a rough lot--and there at daybreak they went as soon as the other customers had left for work. "The place had a bar and six bare tables, and was simply infested with roaches. The only things that I ever could get were coffee made from burnt bread, with brown molasses-cake. I ordered these for Gouraud. The taste of the coffee, the insects, etc., were too much. He fainted. I gave him a big dose of gin, and this revived him. He went back to the works and waited until six when the day men came, and telegraphed for a carriage. He lost all interest in the experiments after that, and I was ordered back to America." Edison states, however, that the automatic was finally adopted in England and used for many years; indeed, is still in use there. But they took whatever was needed from his system, and he "has never had a cent from them."

Arduous work was at once resumed at home on duplex and quadruplex telegraphy, just as though there had been no intermission or discouragement over dots twenty-seven feet long. A clue to his activity is furnished in the fact that in 1872 he had applied for thirty-eight patents in the class of telegraphy, and twenty-five in 1873; several of these being for duplex methods, on which he had experimented. The earlier apparatus had been built several years prior to this, as shown by a curious little item of news that appeared in the Telegrapher of January 30, 1869: "T. A. Edison has resigned his situation in the Western Union office, Boston, and will devote his time to bringing out his inventions." Oh, the supreme, splendid confidence of youth! Six months later, as we have seen, he had already made his mark, and the same journal, in October, 1869, could say: "Mr. Edison is a young man of the highest order of mechanical talent, combined with good scientific electrical knowledge and experience. He has already invented and patented a number of valuable and useful inventions, among which may be mentioned the best instrument for double transmission yet brought out." Not bad for a novice of twenty-two. It is natural, therefore, after his intervening work on indicators, stock tickers, automatic telegraphs, and typewriters, to find him harking back to duplex telegraphy, if, indeed, he can be said to have dropped it in the interval. It has always been one of the characteristic features of Edison's method of inventing that work in several lines has gone forward at the same time. No one line of investigation has ever been enough to occupy his thoughts fully; or to express it otherwise, he has found rest in turning from one field of work to another, having absolutely no recreations or hobbies, and not needing them. It may also be said that, once entering it, Mr. Edison has never abandoned any field of work. He may change the line of attack; he may drop the subject for a time; but sooner or later the note-books or the Patent Office will bear testimony to the reminiscent outcropping of latent thought on the matter. His attention has shifted chronologically, and by process of evolution, from one problem to another, and some results are found to be final; but the interest of the man in the thing never dies out. No one sees more vividly than he the fact that in the interplay of the arts one industry shapes and helps another, and that no invention lives to itself alone.

The path to the quadruplex lay through work on the duplex, which, suggested first by Moses G. Farmer in 1852, had been elaborated by many ingenious inventors, notably in this country by Stearns, before Edison once again applied his mind to it. The different methods of such multiple transmission--namely, the simultaneous dispatch of the two communications in opposite directions over the same wire, or the dispatch of both at once in the same direction--gave plenty of play to ingenuity. Prescott's Elements of the Electric Telegraph, a standard work in its day, described "a method of simultaneous transmission invented by T. A. Edison, of New Jersey, in 1873," and says of it: "Its peculiarity consists in the fact that the signals are transmitted in one direction by reversing the polarity of a constant current, and in the opposite direction by increasing or decreasing the strength of the same current." Herein lay the germ of the Edison quadruplex. It is also noted that "In 1874 Edison invented a method of simultaneous transmission by induced currents, which has given very satisfactory results in experimental trials." Interest in the duplex as a field of invention dwindled, however, as the quadruplex loomed up, for while the one doubled the capacity of a circuit, the latter created three "phantom wires," and thus quadruplexed the working capacity of any line to which it was applied. As will have been gathered from the above, the principle embodied in the quadruplex is that of working over the line with two currents from each end that differ from each other in strength or nature, so that they will affect only instruments adapted to respond to just such currents and no others; and by so arranging the receiving apparatus as not to be affected by the currents transmitted from its own end of the line. Thus by combining instruments that respond only to variation in the strength of current from the distant station, with instruments that respond only to the change in the direction of current from the distant station, and by grouping a pair of these at each end of the line, the quadruplex is the result. Four sending and four receiving operators are kept busy at each end, or eight in all. Aside from other material advantages, it is estimated that at least from $15,000,000 to $20,000,000 has been saved by the Edison quadruplex merely in the cost of line construction in America.

The quadruplex has not as a rule the same working efficiency that four separate wires have. This is due to the fact that when one of the receiving operators is compelled to "break" the sending operator for any reason, the "break" causes the interruption of the work of eight operators, instead of two, as would be the case on a single wire. The working efficiency of the quadruplex, therefore, with the apparatus in good working condition, depends entirely upon the skill of the operators employed to operate it. But this does not reflect upon or diminish the ingenuity required for its invention. Speaking of the problem involved, Edison said some years later to Mr. Upton, his mathematical assistant, that "he always considered he was only working from one room to another. Thus he was not confused by the amount of wire and the thought of distance."

The immense difficulties of reducing such a system to practice may be readily conceived, especially when it is remembered that the "line" itself, running across hundreds of miles of country, is subject to all manner of atmospheric conditions, and varies from moment to moment in its ability to carry current, and also when it is borne in mind that the quadruplex requires at each end of the line a so-called "artificial line," which must have the exact resistance of the working line and must be varied with the variations in resistance of the working line. At this juncture other schemes were fermenting in his brain; but the quadruplex engrossed him. "This problem was of most difficult and complicated kind, and I bent all my energies toward its solution. It required a peculiar effort of the mind, such as the imagining of eight different things moving simultaneously on a mental plane, without anything to demonstrate their efficiency." It is perhaps hardly to be wondered at that when notified he would have to pay 12 1/2 per cent. extra if his taxes in Newark were not at once paid, he actually forgot his own name when asked for it suddenly at the City Hall, lost his place in the line, and, the fatal hour striking, had to pay the surcharge after all!

So important an invention as the quadruplex could not long go begging, but there were many difficulties connected with its introduction, some of which are best described in Mr. Edison's own words: "Around 1873 the owners of the Automatic Telegraph Company commenced negotiations with Jay Gould for the purchase of the wires between New York and Washington, and the patents for the system, then in successful operation. Jay Gould at that time controlled the Atlantic & Pacific Telegraph Company, and was competing with the Western Union and endeavoring to depress Western Union stock on the Exchange. About this time I invented the quadruplex. I wanted to interest the Western Union Telegraph Company in it, with a view of selling it, but was unsuccessful until I made an arrangement with the chief electrician of the company, so that he could be known as a joint inventor and receive a portion of the money. At that time I was very short of money, and needed it more than glory. This electrician appeared to want glory more than money, so it was an easy trade. I brought my apparatus over and was given a separate room with a marble-tiled floor, which, by-the-way, was a very hard kind of floor to sleep on, and started in putting on the finishing touches.

"After two months of very hard work, I got a detail at regular times of eight operators, and we got it working nicely from one room to another over a wire which ran to Albany and back. Under certain conditions of weather, one side of the quadruplex would work very shakily, and I had not succeeded in ascertaining the cause of the trouble. On a certain day, when there was a board meeting of the company, I was to make an exhibition test. The day arrived. I had picked the best operators in New York, and they were familiar with the apparatus. I arranged that if a storm occurred, and the bad side got shaky, they should do the best they could and draw freely on their imaginations. They were sending old messages. About 1, o'clock everything went wrong, as there was a storm somewhere near Albany, and the bad side got shaky. Mr. Orton, the president, and Wm. H. Vanderbilt and the other directors came in. I had my heart trying to climb up around my oesophagus. I was paying a sheriff five dollars a day to withhold judgment which had been entered against me in a case which I had paid no attention to; and if the quadruplex had not worked before the president, I knew I was to have trouble and might lose my machinery. The New York Times came out next day with a full account. I was given $5000 as part payment for the invention, which made me easy, and I expected the whole thing would be closed up. But Mr. Orton went on an extended tour just about that time. I had paid for all the experiments on the quadruplex and exhausted the money, and I was again in straits. In the mean time I had introduced the apparatus on the lines of the company, where it was very successful.

"At that time the general superintendent of the Western Union was Gen. T. T. Eckert (who had been Assistant Secretary of War with Stanton). Eckert was secretly negotiating with Gould to leave the Western Union and take charge of the Atlantic & Pacific--Gould's company. One day Eckert called me into his office and made inquiries about money matters. I told him Mr. Orton had gone off and left me without means, and I was in straits. He told me I would never get another cent, but that he knew a man who would buy it. I told him of my arrangement with the electrician, and said I could not sell it as a whole to anybody; but if I got enough for it, I would sell all my interest in any SHARE I might have. He seemed to think his party would agree to this. I had a set of quadruplex over in my shop, 10 and 12 Ward Street, Newark, and he arranged to bring him over next evening to see the apparatus. So the next morning Eckert came over with Jay Gould and introduced him to me. This was the first time I had ever seen him. I exhibited and explained the apparatus, and they departed. The next day Eckert sent for me, and I was taken up to Gould's house, which was near the Windsor Hotel, Fifth Avenue. In the basement he had an office. It was in the evening, and we went in by the servants' entrance, as Eckert probably feared that he was watched. Gould started in at once and asked me how much I wanted. I said: 'Make me an offer.' Then he said: 'I will give you $30,000.' I said: 'I will sell any interest I may have for that money,' which was something more than I thought I could get. The next morning I went with Gould to the office of his lawyers, Sherman & Sterling, and received a check for $30,000, with a remark by Gould that I had got the steamboat Plymouth Rock, as he had sold her for $30,000 and had just received the check. There was a big fight on between Gould's company and the Western Union, and this caused more litigation. The electrician, on account of the testimony involved, lost his glory. The judge never decided the case, but went crazy a few months afterward." It was obviously a characteristically shrewd move on the part of Mr. Gould to secure an interest in the quadruplex, as a factor in his campaign against the Western Union, and as a decisive step toward his control of that system, by the subsequent merger that included not only the Atlantic & Pacific Telegraph Company, but the American Union Telegraph Company.

Nor was Mr. Gould less appreciative of the value of Edison's automatic system. Referring to matters that will be taken up later in the narrative, Edison says: "After this Gould wanted me to help install the automatic system in the Atlantic & Pacific company, of which General Eckert had been elected president, the company having bought the Automatic Telegraph Company. I did a lot of work for this company making automatic apparatus in my shop at Newark. About this time I invented a district messenger call-box system, and organized a company called the Domestic Telegraph Company, and started in to install the system in New York. I had great difficulty in getting subscribers, having tried several canvassers, who, one after the other, failed to get subscribers. When I was about to give it up, a test operator named Brown, who was on the Automatic Telegraph wire between New York and Washington, which passed through my Newark shop, asked permission to let him try and see if he couldn't get subscribers. I had very little faith in his ability to get any, but I thought I would give him a chance, as he felt certain of his ability to succeed. He started in, and the results were surprising. Within a month he had procured two hundred subscribers, and the company was a success. I have never quite understood why six men should fail absolutely, while the seventh man should succeed. Perhaps hypnotism would account for it. This company was sold out to the Atlantic & Pacific company." As far back as 1872, Edison had applied for a patent on district messenger signal boxes, but it was not issued until January, 1874, another patent being granted in September of the same year. In this field of telegraph application, as in others, Edison was a very early comer, his only predecessor being the fertile and ingenious Callahan, of stock-ticker fame. The first president of the Gold & Stock Telegraph Company, Elisha W. Andrews, had resigned in 1870 in order to go to England to introduce the stock ticker in London. He lived in Englewood, New Jersey, and the very night he had packed his trunk the house was burglarized. Calling on his nearest friend the next morning for even a pair of suspenders, Mr. Andrews was met with regrets of inability, because the burglars had also been there. A third and fourth friend in the vicinity was appealed to with the same disheartening reply of a story of wholesale spoliation. Mr. Callahan began immediately to devise a system of protection for Englewood; but at that juncture a servant-girl who had been for many years with a family on the Heights in Brooklyn went mad suddenly and held an aged widow and her daughter as helpless prisoners for twenty-four hours without food or water. This incident led to an extension of the protective idea, and very soon a system was installed in Brooklyn with one hundred subscribers. Out of this grew in turn the district messenger system, for it was just as easy to call a messenger as to sound a fire-alarm or summon the police. To-day no large city in America is without a service of this character, but its function was sharply limited by the introduction of the telephone.

Returning to the automatic telegraph it is interesting to note that so long as Edison was associated with it as a supervising providence it did splendid work, which renders the later neglect of automatic or "rapid telegraphy" the more remarkable. Reid's standard Telegraph in America bears astonishing testimony on this point in 1880, as follows: "The Atlantic & Pacific Telegraph Company had twenty-two automatic stations. These included the chief cities on the seaboard, Buffalo, Chicago, and Omaha. The through business during nearly two years was largely transmitted in this way. Between New York and Boston two thousand words a minute have been sent. The perforated paper was prepared at the rate of twenty words per minute. Whatever its demerits this system enabled the Atlantic & Pacific company to handle a much larger business during 1875 and 1876 than it could otherwise have done with its limited number of wires in their then condition." Mr. Reid also notes as a very thorough test of the perfect practicability of the system, that it handled the President's message, December 3, 1876, of 12,600 words with complete success. This long message was filed at Washington at 1.05 and delivered in New York at 2.07. The first 9000 words were transmitted in forty-five minutes. The perforated strips were prepared in thirty minutes by ten persons, and duplicated by nine copyists. But to-day, nearly thirty-five years later, telegraphy in America is still practically on a basis of hand transmission!

Of this period and his association with Jay Gould, some very interesting glimpses are given by Edison. "While engaged in putting in the automatic system, I saw a great deal of Gould, and frequently went uptown to his office to give information. Gould had no sense of humor. I tried several times to get off what seemed to me a funny story, but he failed to see any humor in them. I was very fond of stories, and had a choice lot, always kept fresh, with which I could usually throw a man into convulsions. One afternoon Gould started in to explain the great future of the Union Pacific Railroad, which he then controlled. He got a map, and had an immense amount of statistics. He kept at it for over four hours, and got very enthusiastic. Why he should explain to me, a mere inventor, with no capital or standing, I couldn't make out. He had a peculiar eye, and I made up my mind that there was a strain of insanity somewhere. This idea was strengthened shortly afterward when the Western Union raised the monthly rental of the stock tickers. Gould had one in his house office, which he watched constantly. This he had removed, to his great inconvenience, because the price had been advanced a few dollars! He railed over it. This struck me as abnormal. I think Gould's success was due to abnormal development. He certainly had one trait that all men must have who want to succeed. He collected every kind of information and statistics about his schemes, and had all the data. His connection with men prominent in official life, of which I was aware, was surprising to me. His conscience seemed to be atrophied, but that may be due to the fact that he was contending with men who never had any to be atrophied. He worked incessantly until 12 or 1 o'clock at night. He took no pride in building up an enterprise. He was after money, and money only. Whether the company was a success or a failure mattered not to him. After he had hammered the Western Union through his opposition company and had tired out Mr. Vanderbilt, the latter retired from control, and Gould went in and consolidated his company and controlled the Western Union. He then repudiated the contract with the Automatic Telegraph people, and they never received a cent for their wires or patents, and I lost three years of very hard labor. But I never had any grudge against him, because he was so able in his line, and as long as my part was successful the money with me was a secondary consideration. When Gould got the Western Union I knew no further progress in telegraphy was possible, and I went into other lines." The truth is that General Eckert was a conservative--even a reactionary--and being prejudiced like many other American telegraph managers against "machine telegraphy," threw out all such improvements.

The course of electrical history has been variegated by some very remarkable litigation; but none was ever more extraordinary than that referred to here as arising from the transfer of the Automatic Telegraph Company to Mr. Jay Gould and the Atlantic & Pacific Telegraph Company. The terms accepted by Colonel Reiff from Mr. Gould, on December 30, 1874, provided that the purchasing telegraph company should increase its capital to $15,000,000, of which the Automatic interests were to receive $4,000,000 for their patents, contracts, etc. The stock was then selling at about 25, and in the later consolidation with the Western Union "went in" at about 60; so that the real purchase price was not less than $1,000,000 in cash. There was a private arrangement in writing with Mr. Gould that he was to receive one-tenth of the "result" to the Automatic group, and a tenth of the further results secured at home and abroad. Mr. Gould personally bought up and gave money and bonds for one or two individual interests on the above basis, including that of Harrington, who in his representative capacity executed assignments to Mr. Gould. But payments were then stopped, and the other owners were left without any compensation, although all that belonged to them in the shape of property and patents was taken over bodily into Atlantic & Pacific hands, and never again left them. Attempts at settlement were made in their behalf, and dragged wearily, due apparently to the fact that the plans were blocked by General Eckert, who had in some manner taken offence at a transaction effected without his active participation in all the details. Edison, who became under the agreement the electrician of the Atlantic & Pacific Telegraph Company, has testified to the unfriendly attitude assumed toward him by General Eckert, as president. In a graphic letter from Menlo Park to Mr. Gould, dated February 2, 1877, Edison makes a most vigorous and impassioned complaint of his treatment, "which, acting cumulatively, was a long, unbroken disappointment to me"; and he reminds Mr. Gould of promises made to him the day the transfer had been effected of Edison's interest in the quadruplex. The situation was galling to the busy, high-spirited young inventor, who, moreover, "had to live"; and it led to his resumption of work for the Western Union Telegraph Company, which was only too glad to get him back. Meantime, the saddened and perplexed Automatic group was left unpaid, and it was not until 1906, on a bill filed nearly thirty years before, that Judge Hazel, in the United States Circuit Court for the Southern District of New York, found strongly in favor of the claimants and ordered an accounting. The court held that there had been a most wrongful appropriation of the patents, including alike those relating to the automatic, the duplex, and the quadruplex, all being included in the general arrangement under which Mr. Gould had held put his tempting bait of $4,000,000. In the end, however, the complainant had nothing to show for all his struggle, as the master who made the accounting set the damages at one dollar!

Aside from the great value of the quadruplex, saving millions of dollars, for a share in which Edison received $30,000, the automatic itself is described as of considerable utility by Sir William Thomson in his juror report at the Centennial Exposition of 1876, recommending it for award. This leading physicist of his age, afterward Lord Kelvin, was an adept in telegraphy, having made the ocean cable talk, and he saw in Edison's "American Automatic," as exhibited by the Atlantic & Pacific company, a most meritorious and useful system. With the aid of Mr. E. H. Johnson he made exhaustive tests, carrying away with him to Glasgow University the surprising records that he obtained. His official report closes thus: "The electromagnetic shunt with soft iron core, invented by Mr. Edison, utilizing Professor Henry's discovery of electromagnetic induction in a single circuit to produce a momentary reversal of the line current at the instant when the battery is thrown off and so cut off the chemical marks sharply at the proper instant, is the electrical secret of the great speed he has achieved. The main peculiarities of Mr. Edison's automatic telegraph shortly stated in conclusion are: (1) the perforator; (2) the contact-maker; (3) the electromagnetic shunt; and (4) the ferric cyanide of iron solution. It deserves award as a very important step in land telegraphy." The attitude thus disclosed toward Mr. Edison's work was never changed, except that admiration grew as fresh inventions were brought forward. To the day of his death Lord Kelvin remained on terms of warmest friendship with his American co-laborer, with whose genius he thus first became acquainted at Philadelphia in the environment of Franklin.

It is difficult to give any complete idea of the activity maintained at the Newark shops during these anxious, harassed years, but the statement that at one time no fewer than forty-five different inventions were being worked upon, will furnish some notion of the incandescent activity of the inventor and his assistants. The hours were literally endless; and upon one occasion, when the order was in hand for a large quantity of stock tickers, Edison locked his men in until the job had been finished of making the machine perfect, and "all the bugs taken out," which meant sixty hours of unintermitted struggle with the difficulties. Nor were the problems and inventions all connected with telegraphy. On the contrary, Edison's mind welcomed almost any new suggestion as a relief from the regular work in hand. Thus: "Toward the latter part of 1875, in the Newark shop, I invented a device for multiplying copies of letters, which I sold to Mr. A. B. Dick, of Chicago, and in the years since it has been universally introduced throughout the world. It is called the 'Mimeograph.' I also invented devices for and introduced paraffin paper, now used universally for wrapping up candy, etc." The mimeograph employs a pointed stylus, used as in writing with a lead-pencil, which is moved over a kind of tough prepared paper placed on a finely grooved steel plate. The writing is thus traced by means of a series of minute perforations in the sheet, from which, as a stencil, hundreds of copies can be made. Such stencils can be prepared on typewriters. Edison elaborated this principle in two other forms--one pneumatic and one electric--the latter being in essence a reciprocating motor. Inside the barrel of the electric pen a little plunger, carrying the stylus, travels to and fro at a very high rate of speed, due to the attraction and repulsion of the solenoid coils of wire surrounding it; and as the hand of the writer guides it the pen thus makes its record in a series of very minute perforations in the paper. The current from a small battery suffices to energize the pen, and with the stencil thus made hundreds of copies of the document can be furnished. As a matter of fact, as many as three thousand copies have been made from a single mimeographic stencil of this character.

IX. THE TELEPHONE, MOTOGRAPH, AND MICROPHONE

A VERY great invention has its own dramatic history. Episodes full of human interest attend its development. The periods of weary struggle, the daring adventure along unknown paths, the clash of rival claimants, are closely similar to those which mark the revelation and subjugation of a new continent. At the close of the epoch of discovery it is seen that mankind as a whole has made one more great advance; but in the earlier stages one watched chiefly the confused vicissitudes of fortune of the individual pioneers. The great modern art of telephony has had thus in its beginnings, its evolution, and its present status as a universal medium of intercourse, all the elements of surprise, mystery, swift creation of wealth, tragic interludes, and colossal battle that can appeal to the imagination and hold public attention. And in this new electrical industry, in laying its essential foundations, Edison has again been one of the dominant figures.

As far back as 1837, the American, Page, discovered the curious fact that an iron bar, when magnetized and demagnetized at short intervals of time, emitted sounds due to the molecular disturbances in the mass. Philipp Reis, a simple professor in Germany, utilized this principle in the construction of apparatus for the transmission of sound; but in the grasp of the idea he was preceded by Charles Bourseul, a young French soldier in Algeria, who in 1854, under the title of "Electrical Telephony," in a Parisian illustrated paper, gave a brief and lucid description as follows:

"We know that sounds are made by vibrations, and are made sensible to the ear by the same vibrations, which are reproduced by the intervening medium. But the intensity of the vibrations diminishes very rapidly with the distance; so that even with the aid of speaking-tubes and trumpets it is impossible to exceed somewhat narrow limits. Suppose a man speaks near a movable disk sufficiently flexible to lose none of the vibrations of the voice; that this disk alternately makes and breaks the connection with a battery; you may have at a distance another disk which will simultaneously execute the same vibrations.... Any one who is not deaf and dumb may use this mode of transmission, which would require no apparatus except an electric battery, two vibrating disks, and a wire."

This would serve admirably for a portrayal of the Bell telephone, except that it mentions distinctly the use of the make-and-break method (i. e., where the circuit is necessarily opened and closed as in telegraphy, although, of course, at an enormously higher rate), which has never proved practical.

So far as is known Bourseul was not practical enough to try his own suggestion, and never made a telephone. About 1860, Reis built several forms of electrical telephonic apparatus, all imitating in some degree the human ear, with its auditory tube, tympanum, etc., and examples of the apparatus were exhibited in public not only in Germany, but in England. There is a variety of testimony to the effect that not only musical sounds, but stray words and phrases, were actually transmitted with mediocre, casual success. It was impossible, however, to maintain the devices in adjustment for more than a few seconds, since the invention depended upon the make-and-break principle, the circuit being made and broken every time an impulse-creating sound went through it, causing the movement of the diaphragm on which the sound-waves impinged. Reis himself does not appear to have been sufficiently interested in the marvellous possibilities of the idea to follow it up--remarking to the man who bought his telephonic instruments and tools that he had shown the world the way. In reality it was not the way, although a monument erected to his memory at Frankfort styles him the inventor of the telephone. As one of the American judges said, in deciding an early litigation over the invention of the telephone, a hundred years of Reis would not have given the world the telephonic art for public use. Many others after Reis tried to devise practical make-and-break telephones, and all failed; although their success would have rendered them very valuable as a means of fighting the Bell patent. But the method was a good starting-point, even if it did not indicate the real path. If Reis had been willing to experiment with his apparatus so that it did not make-and-break, he would probably have been the true father of the telephone, besides giving it the name by which it is known. It was not necessary to slam the gate open and shut. All that was required was to keep the gate closed, and rattle the latch softly. Incidentally it may be noted that Edison in experimenting with the Reis transmitter recognized at once the defect caused by the make-and-break action, and sought to keep the gap closed by the use, first, of one drop of water, and later of several drops. But the water decomposed, and the incurable defect was still there.

The Reis telephone was brought to America by Dr. P. H. Van der Weyde, a well-known physicist in his day, and was exhibited by him before a technical audience at Cooper Union, New York, in 1868, and described shortly after in the technical press. The apparatus attracted attention, and a set was secured by Prof. Joseph Henry for the Smithsonian Institution. There the famous philosopher showed and explained it to Alexander Graham Bell, when that young and persevering Scotch genius went to get help and data as to harmonic telegraphy, upon which he was working, and as to transmitting vocal sounds. Bell took up immediately and energetically the idea that his two predecessors had dropped--and reached the goal. In 1875 Bell, who as a student and teacher of vocal physiology had unusual qualifications for determining feasible methods of speech transmission, constructed his first pair of magneto telephones for such a purpose. In February of 1876 his first telephone patent was applied for, and in March it was issued. The first published account of the modern speaking telephone was a paper read by Bell before the American Academy of Arts and Sciences in Boston in May of that year; while at the Centennial Exposition at Philadelphia the public first gained any familiarity with it. It was greeted at once with scientific acclaim and enthusiasm as a distinctly new and great invention, although at first it was regarded more as a scientific toy than as a commercially valuable device.

By an extraordinary coincidence, the very day that Bell's application for a patent went into the United States Patent Office, a caveat was filed there by Elisha Gray, of Chicago, covering the specific idea of transmitting speech and reproducing it in a telegraphic circuit "through an instrument capable of vibrating responsively to all the tones of the human voice, and by which they are rendered audible." Out of this incident arose a struggle and a controversy whose echoes are yet heard as to the legal and moral rights of the two inventors, the assertion even being made that one of the most important claims of Gray, that on a liquid battery transmitter, was surreptitiously "lifted" into the Bell application, then covering only the magneto telephone. It was also asserted that the filing of the Gray caveat antedated by a few hours the filing of the Bell application. All such issues when brought to the American courts were brushed aside, the Bell patent being broadly maintained in all its remarkable breadth and fullness, embracing an entire art; but Gray was embittered and chagrined, and to the last expressed his belief that the honor and glory should have been his. The path of Gray to the telephone was a natural one. A Quaker carpenter who studied five years at Oberlin College, he took up electrical invention, and brought out many ingenious devices in rapid succession in the telegraphic field, including the now universal needle annunciator for hotels, etc., the useful telautograph, automatic self-adjusting relays, private-line printers--leading up to his famous "harmonic" system. This was based upon the principle that a sound produced in the presence of a reed or tuning-fork responding to the sound, and acting as the armature of a magnet in a closed circuit, would, by induction, set up electric impulses in the circuit and cause a distant magnet having a similarly tuned armature to produce the same tone or note. He also found that over the same wire at the same time another series of impulses corresponding to another note could be sent through the agency of a second set of magnets without in any way interfering with the first series of impulses. Building the principle into apparatus, with a keyboard and vibrating "reeds" before his magnets, Doctor Gray was able not only to transmit music by his harmonic telegraph, but went so far as to send nine different telegraph messages at the same instant, each set of instruments depending on its selective note, while any intermediate office could pick up the message for itself by simply tuning its relays to the keynote required. Theoretically the system could be split up into any number of notes and semi-tones. Practically it served as the basis of some real telegraphic work, but is not now in use. Any one can realize, however, that it did not take so acute and ingenious a mind very long to push forward to the telephone, as a dangerous competitor with Bell, who had also, like Edison, been working assiduously in the field of acoustic and multiple telegraphs. Seen in the retrospect, the struggle for the goal at this moment was one of the memorable incidents in electrical history.

Among the interesting papers filed at the Orange Laboratory is a lithograph, the size of an ordinary patent drawing, headed "First Telephone on Record." The claim thus made goes back to the period when all was war, and when dispute was hot and rife as to the actual invention of the telephone. The device shown, made by Edison in 1875, was actually included in a caveat filed January 14, 1876, a month before Bell or Gray. It shows a little solenoid arrangement, with one end of the plunger attached to the diaphragm of a speaking or resonating chamber. Edison states that while the device is crudely capable of use as a magneto telephone, he did not invent it for transmitting speech, but as an apparatus for analyzing the complex waves arising from various sounds. It was made in pursuance of his investigations into the subject of harmonic telegraphs. He did not try the effect of sound-waves produced by the human voice until Bell came forward a few months later; but he found then that this device, made in 1875, was capable of use as a telephone. In his testimony and public utterances Edison has always given Bell credit for the discovery of the transmission of articulate speech by talking against a diaphragm placed in front of an electromagnet; but it is only proper here to note, in passing, the curious fact that he had actually produced a device that COULD talk, prior to 1876, and was therefore very close to Bell, who took the one great step further. A strong characterization of the value and importance of the work done by Edison in the development of the carbon transmitter will be found in the decision of Judge Brown in the United States Circuit Court of Appeals, sitting in Boston, on February 27, 1901, declaring void the famous Berliner patent of the Bell telephone system. [5]

[Footnote 5: See Federal Reporter, vol. 109, p. 976 et seq.]

Bell's patent of 1876 was of an all-embracing character, which only the make-and-break principle, if practical, could have escaped. It was pointed out in the patent that Bell discovered the great principle that electrical undulations induced by the vibrations of a current produced by sound-waves can be represented graphically by the same sinusoidal curve that expresses the original sound vibrations themselves; or, in other words, that a curve representing sound vibrations will correspond precisely to a curve representing electric impulses produced or generated by those identical sound vibrations--as, for example, when the latter impinge upon a diaphragm acting as an armature of an electromagnet, and which by movement to and fro sets up the electric impulses by induction. To speak plainly, the electric impulses correspond in form and character to the sound vibration which they represent. This reduced to a patent "claim" governed the art as firmly as a papal bull for centuries enabled Spain to hold the Western world. The language of the claim is: "The method of and apparatus for transmitting vocal or other sounds telegraphically as herein described, by causing electrical undulations similar in form to the vibrations of the air accompanying the said vocal or other sounds substantially as set forth." It was a long time, however, before the inclusive nature of this grant over every possible telephone was understood or recognized, and litigation for and against the patent lasted during its entire life. At the outset, the commercial value of the telephone was little appreciated by the public, and Bell had the greatest difficulty in securing capital; but among far-sighted inventors there was an immediate "rush to the gold fields." Bell's first apparatus was poor, the results being described by himself as "unsatisfactory and discouraging," which was almost as true of the devices he exhibited at the Philadelphia Centennial. The new-comers, like Edison, Berliner, Blake, Hughes, Gray, Dolbear, and others, brought a wealth of ideas, a fund of mechanical ingenuity, and an inventive ability which soon made the telephone one of the most notable gains of the century, and one of the most valuable additions to human resources. The work that Edison did was, as usual, marked by infinite variety of method as well as by the power to seize on the one needed element of practical success. Every one of the six million telephones in use in the United States, and of the other millions in use through out the world, bears the imprint of his genius, as at one time the instruments bore his stamped name. For years his name was branded on every Bell telephone set, and his patents were a mainstay of what has been popularly called the "Bell monopoly." Speaking of his own efforts in this field, Mr. Edison says:

"In 1876 I started again to experiment for the Western Union and Mr. Orton. This time it was the telephone. Bell invented the first telephone, which consisted of the present receiver, used both as a transmitter and a receiver (the magneto type). It was attempted to introduce it commercially, but it failed on account of its faintness and the extraneous sounds which came in on its wires from various causes. Mr. Orton wanted me to take hold of it and make it commercial. As I had also been working on a telegraph system employing tuning-forks, simultaneously with both Bell and Gray, I was pretty familiar with the subject. I started in, and soon produced the carbon transmitter, which is now universally used.

"Tests were made between New York and Philadelphia, also between New York and Washington, using regular Western Union wires. The noises were so great that not a word could be heard with the Bell receiver when used as a transmitter between New York and Newark, New Jersey. Mr. Orton and W. K. Vanderbilt and the board of directors witnessed and took part in the tests. The Western Union then put them on private lines. Mr. Theodore Puskas, of Budapest, Hungary, was the first man to suggest a telephone exchange, and soon after exchanges were established. The telephone department was put in the hands of Hamilton McK. Twombly, Vanderbilt's ablest son-in-law, who made a success of it. The Bell company, of Boston, also started an exchange, and the fight was on, the Western Union pirating the Bell receiver, and the Boston company pirating the Western Union transmitter. About this time I wanted to be taken care of. I threw out hints of this desire. Then Mr. Orton sent for me. He had learned that inventors didn't do business by the regular process, and concluded he would close it right up. He asked me how much I wanted. I had made up my mind it was certainly worth $25,000, if it ever amounted to anything for central-station work, so that was the sum I had in mind to stick to and get--obstinately. Still it had been an easy job, and only required a few months, and I felt a little shaky and uncertain. So I asked him to make me an offer. He promptly said he would give me $100,000. 'All right,' I said. 'It is yours on one condition, and that is that you do not pay it all at once, but pay me at the rate of $6000 per year for seventeen years'--the life of the patent. He seemed only too pleased to do this, and it was closed. My ambition was about four times too large for my business capacity, and I knew that I would soon spend this money experimenting if I got it all at once, so I fixed it that I couldn't. I saved seventeen years of worry by this stroke."

Thus modestly is told the debut of Edison in the telephone art, to which with his carbon transmitter he gave the valuable principle of varying the resistance of the transmitting circuit with changes in the pressure, as well as the vital practice of using the induction coil as a means of increasing the effective length of the talking circuit. Without these, modern telephony would not and could not exist. [6] But Edison, in telephonic work, as in other directions, was remarkably fertile and prolific. His first inventions in the art, made in 1875-76, continue through many later years, including all kinds of carbon instruments --the water telephone, electrostatic telephone, condenser telephone, chemical telephone, various magneto telephones, inertia telephone, mercury telephone, voltaic pile telephone, musical transmitter, and the electromotograph. All were actually made and tested.

[Footnote 6: Briefly stated, the essential difference between Bell's telephone and Edison's is this: With the former the sound vibrations impinge upon a steel diaphragm arranged adjacent to the pole of a bar electromagnet, whereby the diaphragm acts as an armature, and by its vibrations induces very weak electric impulses in the magnetic coil. These impulses, according to Bell's theory, correspond in form to the sound-waves, and passing over the line energize the magnet coil at the receiving end, and by varying the magnetism cause the receiving diaphragm to be similarly vibrated to reproduce the sounds. A single apparatus is therefore used at each end, performing the double function of transmitter and receiver. With Edison's telephone a closed circuit is used on which is constantly flowing a battery current, and included in that circuit is a pair of electrodes, one or both of which is of carbon. These electrodes are always in contact with a certain initial pressure, so that current will be always flowing over the circuit. One of the electrodes is connected with the diaphragm on which the sound-waves impinge, and the vibration of this diaphragm causes the pressure between the electrodes to be correspondingly varied, and thereby effects a variation in the current, resulting in the production of impulses which actuate the receiving magnet. In other words, with Bell's telephone the sound-waves themselves generate the electric impulses, which are hence extremely faint. With the Edison telephone, the sound-waves actuate an electric valve, so to speak, and permit variations in a current of any desired strength.

A second distinction between the two telephones is this: With the Bell apparatus the very weak electric impulses generated by the vibration of the transmitting diaphragm pass over the entire line to the receiving end, and in consequence the permissible length of line is limited to a few miles under ideal conditions. With Edison's telephone the battery current does not flow on the main line, but passes through the primary circuit of an induction coil, by which corresponding impulses of enormously higher potential are sent out on the main line to the receiving end. In consequence, the line may be hundreds of miles in length. No modern telephone system in use to-day lacks these characteristic features--the varying resistance and the induction coil.]

The principle of the electromotograph was utilized by Edison in more ways than one, first of all in telegraphy at this juncture. The well-known Page patent, which had lingered in the Patent Office for years, had just been issued, and was considered a formidable weapon. It related to the use of a retractile spring to withdraw the armature lever from the magnet of a telegraph or other relay or sounder, and thus controlled the art of telegraphy, except in simple circuits. "There was no known way," remarks Edison, "whereby this patent could be evaded, and its possessor would eventually control the use of what is known as the relay and sounder, and this was vital to telegraphy. Gould was pounding the Western Union on the Stock Exchange, disturbing its railroad contracts, and, being advised by his lawyers that this patent was of great value, bought it. The moment Mr. Orton heard this he sent for me and explained the situation, and wanted me to go to work immediately and see if I couldn't evade it or discover some other means that could be used in case Gould sustained the patent. It seemed a pretty hard job, because there was no known means of moving a lever at the other end of a telegraph wire except by the use of a magnet. I said I would go at it that night. In experimenting some years previously, I had discovered a very peculiar phenomenon, and that was that if a piece of metal connected to a battery was rubbed over a moistened piece of chalk resting on a metal connected to the other pole, when the current passed the friction was greatly diminished. When the current was reversed the friction was greatly increased over what it was when no current was passing. Remembering this, I substituted a piece of chalk rotated by a small electric motor for the magnet, and connecting a sounder to a metallic finger resting on the chalk, the combination claim of Page was made worthless. A hitherto unknown means was introduced in the electric art. Two or three of the devices were made and tested by the company's expert. Mr. Orton, after he had me sign the patent application and got it in the Patent Office, wanted to settle for it at once. He asked my price. Again I said: 'Make me an offer.' Again he named $100,000. I accepted, providing he would pay it at the rate of $6000 a year for seventeen years. This was done, and thus, with the telephone money, I received $12,000 yearly for that period from the Western Union Telegraph Company."

A year or two later the motograph cropped up again in Edison's work in a curious manner. The telephone was being developed in England, and Edison had made arrangements with Colonel Gouraud, his old associate in the automatic telegraph, to represent his interests. A company was formed, a large number of instruments were made and sent to Gouraud in London, and prospects were bright. Then there came a threat of litigation from the owners of the Bell patent, and Gouraud found he could not push the enterprise unless he could avoid using what was asserted to be an infringement of the Bell receiver. He cabled for help to Edison, who sent back word telling him to hold the fort. "I had recourse again," says Edison, "to the phenomenon discovered by me years previous, that the friction of a rubbing electrode passing over a moist chalk surface was varied by electricity. I devised a telephone receiver which was afterward known as the 'loud-speaking telephone,' or 'chalk receiver.' There was no magnet, simply a diaphragm and a cylinder of compressed chalk about the size of a thimble. A thin spring connected to the centre of the diaphragm extended outwardly and rested on the chalk cylinder, and was pressed against it with a pressure equal to that which would be due to a weight of about six pounds. The chalk was rotated by hand. The volume of sound was very great. A person talking into the carbon transmitter in New York had his voice so amplified that he could be heard one thousand feet away in an open field at Menlo Park. This great excess of power was due to the fact that the latter came from the person turning the handle. The voice, instead of furnishing all the power as with the present receiver, merely controlled the power, just as an engineer working a valve would control a powerful engine.

"I made six of these receivers and sent them in charge of an expert on the first steamer. They were welcomed and tested, and shortly afterward I shipped a hundred more. At the same time I was ordered to send twenty young men, after teaching them to become expert. I set up an exchange, around the laboratory, of ten instruments. I would then go out and get each one out of order in every conceivable way, cutting the wires of one, short-circuiting another, destroying the adjustment of a third, putting dirt between the electrodes of a fourth, and so on. A man would be sent to each to find out the trouble. When he could find the trouble ten consecutive times, using five minutes each, he was sent to London. About sixty men were sifted to get twenty. Before all had arrived, the Bell company there, seeing we could not be stopped, entered into negotiations for consolidation. One day I received a cable from Gouraud offering '30,000' for my interest. I cabled back I would accept. When the draft came I was astonished to find it was for L30,000. I had thought it was dollars."

In regard to this singular and happy conclusion, Edison makes some interesting comments as to the attitude of the courts toward inventors, and the difference between American and English courts. "The men I sent over were used to establish telephone exchanges all over the Continent, and some of them became wealthy. It was among this crowd in London that Bernard Shaw was employed before he became famous. The chalk telephone was finally discarded in favor of the Bell receiver--the latter being more simple and cheaper. Extensive litigation with new-comers followed. My carbon-transmitter patent was sustained, and preserved the monopoly of the telephone in England for many years. Bell's patent was not sustained by the courts. Sir Richard Webster, now Chief-Justice of England, was my counsel, and sustained all of my patents in England for many years. Webster has a marvellous capacity for understanding things scientific; and his address before the courts was lucidity itself. His brain is highly organized. My experience with the legal fraternity is that scientific subjects are distasteful to them, and it is rare in this country, on account of the system of trying patent suits, for a judge really to reach the meat of the controversy, and inventors scarcely ever get a decision squarely and entirely in their favor. The fault rests, in my judgment, almost wholly with the system under which testimony to the extent of thousands of pages bearing on all conceivable subjects, many of them having no possible connection with the invention in dispute, is presented to an over-worked judge in an hour or two of argument supported by several hundred pages of briefs; and the judge is supposed to extract some essence of justice from this mass of conflicting, blind, and misleading statements. It is a human impossibility, no matter how able and fair-minded the judge may be. In England the case is different. There the judges are face to face with the experts and other witnesses. They get the testimony first-hand and only so much as they need, and there are no long-winded briefs and arguments, and the case is decided then and there, a few months perhaps after suit is brought, instead of many years afterward, as in this country. And in England, when a case is once finally decided it is settled for the whole country, while here it is not so. Here a patent having once been sustained, say, in Boston, may have to be litigated all over again in New York, and again in Philadelphia, and so on for all the Federal circuits. Furthermore, it seems to me that scientific disputes should be decided by some court containing at least one or two scientific men--men capable of comprehending the significance of an invention and the difficulties of its accomplishment--if justice is ever to be given to an inventor. And I think, also, that this court should have the power to summon before it and examine any recognized expert in the special art, who might be able to testify to FACTS for or against the patent, instead of trying to gather the truth from the tedious essays of hired experts, whose depositions are really nothing but sworn arguments. The real gist of patent suits is generally very simple, and I have no doubt that any judge of fair intelligence, assisted by one or more scientific advisers, could in a couple of days at the most examine all the necessary witnesses; hear all the necessary arguments, and actually decide an ordinary patent suit in a way that would more nearly be just, than can now be done at an expenditure of a hundred times as much money and months and years of preparation. And I have no doubt that the time taken by the court would be enormously less, because if a judge attempts to read the bulky records and briefs, that work alone would require several days.

"Acting as judges, inventors would not be very apt to correctly decide a complicated law point; and on the other hand, it is hard to see how a lawyer can decide a complicated scientific point rightly. Some inventors complain of our Patent Office, but my own experience with the Patent Office is that the examiners are fair-minded and intelligent, and when they refuse a patent they are generally right; but I think the whole trouble lies with the system in vogue in the Federal courts for trying patent suits, and in the fact, which cannot be disputed, that the Federal judges, with but few exceptions, do not comprehend complicated scientific questions. To secure uniformity in the several Federal circuits and correct errors, it has been proposed to establish a central court of patent appeals in Washington. This I believe in; but this court should also contain at least two scientific men, who would not be blind to the sophistry of paid experts. [7] Men whose inventions would have created wealth of millions have been ruined and prevented from making any money whereby they could continue their careers as creators of wealth for the general good, just because the experts befuddled the judge by their misleading statements."

[Footnote 7: As an illustration of the perplexing nature of expert evidence in patent cases, the reader will probably be interested in perusing the following extracts from the opinion of Judge Dayton, in the suit of Bryce Bros. Co. vs. Seneca Glass Co., tried in the United States Circuit Court, Northern District of West Virginia, reported in The Federal Reporter, 140, page 161:

"On this subject of the validity of this patent, a vast amount of conflicting, technical, perplexing, and almost hypercritical discussion and opinion has been indulged, both in the testimony and in the able and exhaustive arguments and briefs of counsel. Expert Osborn for defendant, after setting forth minutely his superior qualifications mechanical education, and great experience, takes up in detail the patent claims, and shows to his own entire satisfaction that none of them are new; that all of them have been applied, under one form or another, in some twenty-two previous patents, and in two other machines, not patented, to-wit, the Central Glass and Kuny Kahbel ones; that the whole machine is only 'an aggregation of well-known mechanical elements that any skilled designer would bring to his use in the construction of such a machine.' This certainly, under ordinary conditions, would settle the matter beyond peradventure; for this witness is a very wise and learned man in these things, and very positive. But expert Clarke appears for the plaintiff, and after setting forth just as minutely his superior qualifications, mechanical education, and great experience, which appear fully equal in all respects to those of expert Osborn, proceeds to take up in detail the patent claims, and shows to his entire satisfaction that all, with possibly one exception, are new, show inventive genius, and distinct advances upon the prior art. In the most lucid, and even fascinating, way he discusses all the parts of this machine, compares it with the others, draws distinctions, points out the merits of the one in controversy and the defects of all the others, considers the twenty-odd patents referred to by Osborn, and in the politest, but neatest, manner imaginable shows that expert Osborn did not know what he was talking about, and sums the whole matter up by declaring this 'invention of Mr. Schrader's, as embodied in the patent in suit, a radical and wide departure, from the Kahbel machine' (admitted on all sides to be nearest prior approach to it), 'a distinct and important advance in the art of engraving glassware, and generally a machine for this purpose which has involved the exercise of the inventive faculty in the highest degree.'

"Thus a more radical and irreconcilable disagreement between experts touching the same thing could hardly be found. So it is with the testimony. If we take that for the defendant, the Central Glass Company machine, and especially the Kuny Kahbel machine, built and operated years before this patent issued, and not patented, are just as good, just as effective and practical, as this one, and capable of turning out just as perfect work and as great a variety of it. On the other hand, if we take that produced by the plaintiff, we are driven to the conclusion that these prior machines, the product of the same mind, were only progressive steps forward from utter darkness, so to speak, into full inventive sunlight, which made clear to him the solution of the problem in this patented machine. The shortcomings of the earlier machines are minutely set forth, and the witnesses for the plaintiff are clear that they are neither practical nor profitable.

"But this is not all of the trouble that confronts us in this case. Counsel of both sides, with an indomitable courage that must command admiration, a courage that has led them to a vast amount of study, investigation, and thought, that in fact has made them all experts, have dissected this record of 356 closely printed pages, applied all mechanical principles and laws to the facts as they see them, and, besides, have ransacked the law-books and cited an enormous number of cases, more or less in point, as illustration of their respective contentions. The courts find nothing more difficult than to apply an abstract principle to all classes of cases that may arise. The facts in each case so frequently create an exception to the general rule that such rule must be honored rather in its breach than in its observance. Therefore, after a careful examination of these cases, it is no criticism of the courts to say that both sides have found abundant and about an equal amount of authority to sustain their respective contentions, and, as a result, counsel have submitted, in briefs, a sum total of 225 closely printed pages, in which they have clearly, yet, almost to a mathematical certainty, demonstrated on the one side that this Schrader machine is new and patentable, and on the other that it is old and not so. Under these circumstances, it would be unnecessary labor and a fruitless task for me to enter into any further technical discussion of the mechanical problems involved, for the purpose of seeking to convince either side of its error. In cases of such perplexity as this generally some incidents appear that speak more unerringly than do the tongues of the witnesses, and to some of these I purpose to now refer."]

Mr. Bernard Shaw, the distinguished English author, has given a most vivid and amusing picture of this introduction of Edison's telephone into England, describing the apparatus as "a much too ingenious invention, being nothing less than a telephone of such stentorian efficiency that it bellowed your most private communications all over the house, instead of whispering them with some sort of discretion." Shaw, as a young man, was employed by the Edison Telephone Company, and was very much alive to his surroundings, often assisting in public demonstrations of the apparatus "in a manner which I am persuaded laid the foundation of Mr. Edison's reputation." The sketch of the men sent over from America is graphic: "Whilst the Edison Telephone Company lasted it crowded the basement of a high pile of offices in Queen Victoria Street with American artificers. These deluded and romantic men gave me a glimpse of the skilled proletariat of the United States. They sang obsolete sentimental songs with genuine emotion; and their language was frightful even to an Irishman. They worked with a ferocious energy which was out of all proportion to the actual result achieved. Indomitably resolved to assert their republican manhood by taking no orders from a tall-hatted Englishman whose stiff politeness covered his conviction that they were relatively to himself inferior and common persons, they insisted on being slave-driven with genuine American oaths by a genuine free and equal American foreman. They utterly despised the artfully slow British workman, who did as little for his wages as he possibly could; never hurried himself; and had a deep reverence for one whose pocket could be tapped by respectful behavior. Need I add that they were contemptuously wondered at by this same British workman as a parcel of outlandish adult boys who sweated themselves for their employer's benefit instead of looking after their own interest? They adored Mr. Edison as the greatest man of all time in every possible department of science, art, and philosophy, and execrated Mr. Graham Bell, the inventor of the rival telephone, as his Satanic adversary; but each of them had (or intended to have) on the brink of completion an improvement on the telephone, usually a new transmitter. They were free-souled creatures, excellent company, sensitive, cheerful, and profane; liars, braggarts, and hustlers, with an air of making slow old England hum, which never left them even when, as often happened, they were wrestling with difficulties of their own making, or struggling in no-thoroughfares, from which they had to be retrieved like stray sheep by Englishmen without imagination enough to go wrong."

Mr. Samuel Insull, who afterward became private secretary to Mr. Edison, and a leader in the development of American electrical manufacturing and the central-station art, was also in close touch with the London situation thus depicted, being at the time private secretary to Colonel Gouraud, and acting for the first half hour as the amateur telephone operator in the first experimental exchange erected in Europe. He took notes of an early meeting where the affairs of the company were discussed by leading men like Sir John Lubbock (Lord Avebury) and the Right Hon. E. P. Bouverie (then a cabinet minister), none of whom could see in the telephone much more than an auxiliary for getting out promptly in the next morning's papers the midnight debates in Parliament. "I remember another incident," says Mr. Insull. "It was at some celebration of one of the Royal Societies at the Burlington House, Piccadilly. We had a telephone line running across the roofs to the basement of the building. I think it was to Tyndall's laboratory in Burlington Street. As the ladies and gentlemen came through, they naturally wanted to look at the great curiosity, the loud-speaking telephone: in fact, any telephone was a curiosity then. Mr. and Mrs. Gladstone came through. I was handling the telephone at the Burlington House end. Mrs. Gladstone asked the man over the telephone whether he knew if a man or woman was speaking; and the reply came in quite loud tones that it was a man!"

With Mr. E. H. Johnson, who represented Edison, there went to England for the furtherance of this telephone enterprise, Mr. Charles Edison, a nephew of the inventor. He died in Paris, October, 1879, not twenty years of age. Stimulated by the example of his uncle, this brilliant youth had already made a mark for himself as a student and inventor, and when only eighteen he secured in open competition the contract to install a complete fire-alarm telegraph system for Port Huron. A few months later he was eagerly welcomed by his uncle at Menlo Park, and after working on the telephone was sent to London to aid in its introduction. There he made the acquaintance of Professor Tyndall, exhibited the telephone to the late King of England; and also won the friendship of the late King of the Belgians, with whom he took up the project of establishing telephonic communication between Belgium and England. At the time of his premature death he was engaged in installing the Edison quadruplex between Brussels and Paris, being one of the very few persons then in Europe familiar with the working of that invention.

Meantime, the telephonic art in America was undergoing very rapid development. In March, 1878, addressing "the capitalists of the Electric Telephone Company" on the future of his invention, Bell outlined with prophetic foresight and remarkable clearness the coming of the modern telephone exchange. Comparing with gas and water distribution, he said: "In a similar manner, it is conceivable that cables of telephone wires could be laid underground or suspended overhead communicating by branch wires with private dwellings, country houses, shops, manufactories, etc., uniting them through the main cable with a central office, where the wire could be connected as desired, establishing direct communication between any two places in the city.... Not only so, but I believe, in the future, wires will unite the head offices of telephone companies in different cities; and a man in one part of the country may communicate by word of mouth with another in a distant place."

All of which has come to pass. Professor Bell also suggested how this could be done by "the employ of a man in each central office for the purpose of connecting the wires as directed." He also indicated the two methods of telephonic tariff--a fixed rental and a toll; and mentioned the practice, now in use on long-distance lines, of a time charge. As a matter of fact, this "centralizing" was attempted in May, 1877, in Boston, with the circuits of the Holmes burglar-alarm system, four banking-houses being thus interconnected; while in January of 1878 the Bell telephone central-office system at New Haven, Connecticut, was opened for business, "the first fully equipped commercial telephone exchange ever established for public or general service."

All through this formative period Bell had adhered to and introduced the magneto form of telephone, now used only as a receiver, and very poorly adapted for the vital function of a speech-transmitter. From August, 1877, the Western Union Telegraph Company worked along the other line, and in 1878, with its allied Gold & Stock Telegraph Company, it brought into existence the American Speaking Telephone Company to introduce the Edison apparatus, and to create telephone exchanges all over the country. In this warfare, the possession of a good battery transmitter counted very heavily in favor of the Western Union, for upon that the real expansion of the whole industry depended; but in a few months the Bell system had its battery transmitter, too, tending to equalize matters. Late in the same year patent litigation was begun which brought out clearly the merits of Bell, through his patent, as the original and first inventor of the electric speaking telephone; and the Western Union Telegraph Company made terms with its rival. A famous contract bearing date of November 10, 1879, showed that under the Edison and other controlling patents the Western Union Company had already set going some eighty-five exchanges, and was making large quantities of telephonic apparatus. In return for its voluntary retirement from the telephonic field, the Western Union Telegraph Company, under this contract, received a royalty of 20 per cent. of all the telephone earnings of the Bell system while the Bell patents ran; and thus came to enjoy an annual income of several hundred thousand dollars for some years, based chiefly on its modest investment in Edison's work. It was also paid several thousand dollars in cash for the Edison, Phelps, Gray, and other apparatus on hand. It secured further 40 per cent. of the stock of the local telephone systems of New York and Chicago; and last, but by no means least, it exacted from the Bell interests an agreement to stay out of the telegraph field.

By March, 1881, there were in the United States only nine cities of more than ten thousand inhabitants, and only one of more than fifteen thousand, without a telephone exchange. The industry thrived under competition, and the absence of it now had a decided effect in checking growth; for when the Bell patent expired in 1893, the total of telephone sets in operation in the United States was only 291,253. To quote from an official Bell statement:

"The brief but vigorous Western Union competition was a kind of blessing in disguise. The very fact that two distinct interests were actively engaged in the work of organizing and establishing competing telephone exchanges all over the country, greatly facilitated the spread of the idea and the growth of the business, and familiarized the people with the use of the telephone as a business agency; while the keenness of the competition, extending to the agents and employees of both companies, brought about a swift but quite unforeseen and unlooked-for expansion in the individual exchanges of the larger cities, and a corresponding advance in their importance, value, and usefulness."

The truth of this was immediately shown in 1894, after the Bell patents had expired, by the tremendous outburst of new competitive activity, in "independent" country systems and toll lines through sparsely settled districts--work for which the Edison apparatus and methods were peculiarly adapted, yet against which the influence of the Edison patent was invoked. The data secured by the United States Census Office in 1902 showed that the whole industry had made gigantic leaps in eight years, and had 2,371,044 telephone stations in service, of which 1,053,866 were wholly or nominally independent of the Bell. By 1907 an even more notable increase was shown, and the Census figures for that year included no fewer than 6,118,578 stations, of which 1,986,575 were "independent." These six million instruments every single set employing the principle of the carbon transmitter--were grouped into 15,527 public exchanges, in the very manner predicted by Bell thirty years before, and they gave service in the shape of over eleven billions of talks. The outstanding capitalized value of the plant was $814,616,004, the income for the year was nearly $185,000,000, and the people employed were 140,000. If Edison had done nothing else, his share in the creation of such an industry would have entitled him to a high place among inventors.

This chapter is of necessity brief in its reference to many extremely interesting points and details; and to some readers it may seem incomplete in its references to the work of other men than Edison, whose influence on telephony as an art has also been considerable. In reply to this pertinent criticism, it may be pointed out that this is a life of Edison, and not of any one else; and that even the discussion of his achievements alone in these various fields requires more space than the authors have at their disposal. The attempt has been made, however, to indicate the course of events and deal fairly with the facts. The controversy that once waged with great excitement over the invention of the microphone, but has long since died away, is suggestive of the difficulties involved in trying to do justice to everybody. A standard history describes the microphone thus:

"A form of apparatus produced during the early days of the telephone by Professor Hughes, of England, for the purpose of rendering faint, indistinct sounds distinctly audible, depended for its operation on the changes that result in the resistance of loose contacts. This apparatus was called the microphone, and was in reality but one of the many forms that it is possible to give to the telephone transmitter. For example, the Edison granular transmitter was a variety of microphone, as was also Edison's transmitter, in which the solid button of carbon was employed. Indeed, even the platinum point, which in the early form of the Reis transmitter pressed against the platinum contact cemented to the centre of the diaphragm, was a microphone."

At a time when most people were amazed at the idea of hearing, with the aid of a "microphone," a fly walk at a distance of many miles, the priority of invention of such a device was hotly disputed. Yet without desiring to take anything from the credit of the brilliant American, Hughes, whose telegraphic apparatus is still in use all over Europe, it may be pointed out that this passage gives Edison the attribution of at least two original forms of which those suggested by Hughes were mere variations and modifications. With regard to this matter, Mr. Edison himself remarks: "After I sent one of my men over to London especially, to show Preece the carbon transmitter, and where Hughes first saw it, and heard it--then within a month he came out with the microphone, without any acknowledgment whatever. Published dates will show that Hughes came along after me."

There have been other ways also in which Edison has utilized the peculiar property that carbon possesses of altering its resistance to the passage of current, according to the pressure to which it is subjected, whether at the surface, or through closer union of the mass. A loose road with a few inches of dust or pebbles on it offers appreciable resistance to the wheels of vehicles travelling over it; but if the surface is kept hard and smooth the effect is quite different. In the same way carbon, whether solid or in the shape of finely divided powder, offers a high resistance to the passage of electricity; but if the carbon is squeezed together the conditions change, with less resistance to electricity in the circuit. For his quadruplex system, Mr. Edison utilized this fact in the construction of a rheostat or resistance box. It consists of a series of silk disks saturated with a sizing of plumbago and well dried. The disks are compressed by means of an adjustable screw; and in this manner the resistance of a circuit can be varied over a wide range.

In like manner Edison developed a "pressure" or carbon relay, adapted to the transference of signals of variable strength from one circuit to another. An ordinary relay consists of an electromagnet inserted in the main line for telegraphing, which brings a local battery and sounder circuit into play, reproducing in the local circuit the signals sent over the main line. The relay is adjusted to the weaker currents likely to be received, but the signals reproduced on the sounder by the agency of the relay are, of course, all of equal strength, as they depend upon the local battery, which has only this steady work to perform. In cases where it is desirable to reproduce the signals in the local circuit with the same variations in strength as they are received by the relay, the Edison carbon pressure relay does the work. The poles of the electromagnet in the local circuit are hollowed out and filled up with carbon disks or powdered plumbago. The armature and the carbon-tipped poles of the electromagnet form part of the local circuit; and if the relay is actuated by a weak current the armature will be attracted but feebly. The carbon being only slightly compressed will offer considerable resistance to the flow of current from the local battery, and therefore the signal on the local sounder will be weak. If, on the contrary, the incoming current on the main line be strong, the armature will be strongly attracted, the carbon will be sharply compressed, the resistance in the local circuit will be proportionately lowered, and the signal heard on the local sounder will be a loud one. Thus it will be seen, by another clever juggle with the willing agent, carbon, for which he has found so many duties, Edison is able to transfer or transmit exactly, to the local circuit, the main-line current in all its minutest variations.

In his researches to determine the nature of the motograph phenomena, and to open up other sources of electrical current generation, Edison has worked out a very ingenious and somewhat perplexing piece of apparatus known as the "chalk battery." It consists of a series of chalk cylinders mounted on a shaft revolved by hand. Resting against each of these cylinders is a palladium-faced spring, and similar springs make contact with the shaft between each cylinder. By connecting all these springs in circuit with a galvanometer and revolving the shaft rapidly, a notable deflection is obtained of the galvanometer needle, indicating the production of electrical energy. The reason for this does not appear to have been determined.

Last but not least, in this beautiful and ingenious series, comes the "tasimeter," an instrument of most delicate sensibility in the presence of heat. The name is derived from the Greek, the use of the apparatus being primarily to measure extremely minute differences of pressure. A strip of hard rubber with pointed ends rests perpendicularly on a platinum plate, beneath which is a carbon button, under which again lies another platinum plate. The two plates and the carbon button form part of an electric circuit containing a battery and a galvanometer. The hard-rubber strip is exceedingly sensitive to heat. The slightest degree of heat imparted to it causes it to expand invisibly, thus increasing the pressure contact on the carbon button and producing a variation in the resistance of the circuit, registered immediately by the little swinging needle of the galvanometer. The instrument is so sensitive that with a delicate galvanometer it will show the impingement of the heat from a person's hand thirty feet away. The suggestion to employ such an apparatus in astronomical observations occurs at once, and it may be noted that in one instance the heat of rays of light from the remote star Arcturus gave results.

X. THE PHONOGRAPH

AT the opening of the Electrical Show in New York City in October, 1908, to celebrate the jubilee of the Atlantic Cable and the first quarter century of lighting with the Edison service on Manhattan Island, the exercises were all conducted by means of the Edison phonograph. This included the dedicatory speech of Governor Hughes, of New York; the modest remarks of Mr. Edison, as president; the congratulations of the presidents of several national electric bodies, and a number of vocal and instrumental selections of operatic nature. All this was heard clearly by a very large audience, and was repeated on other evenings. The same speeches were used again phonographically at the Electrical Show in Chicago in 1909--and now the records are preserved for reproduction a hundred or a thousand years hence. This tour de force, never attempted before, was merely an exemplification of the value of the phonograph not only in establishing at first hand the facts of history, but in preserving the human voice. What would we not give to listen to the very accents and tones of the Sermon on the Mount, the orations of Demosthenes, the first Pitt's appeal for American liberty, the Farewell of Washington, or the Address at Gettysburg? Until Edison made his wonderful invention in 1877, the human race was entirely without means for preserving or passing on to posterity its own linguistic utterances or any other vocal sound. We have some idea how the ancients looked and felt and wrote; the abundant evidence takes us back to the cave-dwellers. But all the old languages are dead, and the literary form is their embalmment. We do not even know definitely how Shakespeare's and Goldsmith's plays were pronounced on the stage in the theatres of the time; while it is only a guess that perhaps Chaucer would sound much more modern than he scans.

The analysis of sound, which owes so much to Helmholtz, was one step toward recording; and the various means of illustrating the phenomena of sound to the eye and ear, prior to the phonograph, were all ingenious. One can watch the dancing little flames of Koenig, and see a voice expressed in tongues of fire; but the record can only be photographic. In like manner, the simple phonautograph of Leon Scott, invented about 1858, records on a revolving cylinder of blackened paper the sound vibrations transmitted through a membrane to which a tiny stylus is attached; so that a human mouth uses a pen and inscribes its sign vocal. Yet after all we are just as far away as ever from enabling the young actors at Harvard to give Aristophanes with all the true, subtle intonation and inflection of the Athens of 400 B.C. The instrument is dumb. Ingenuity has been shown also in the invention of "talking-machines," like Faber's, based on the reed organ pipe. These automata can be made by dexterous manipulation to jabber a little, like a doll with its monotonous "ma-ma," or a cuckoo clock; but they lack even the sterile utility of the imitative art of ventriloquism. The real great invention lies in creating devices that shall be able to evoke from tinfoil, wax, or composition at any time to-day or in the future the sound that once was as evanescent as the vibrations it made on the air.

Contrary to the general notion, very few of the great modern inventions have been the result of a sudden inspiration by which, Minerva-like, they have sprung full-fledged from their creators' brain; but, on the contrary, they have been evolved by slow and gradual steps, so that frequently the final advance has been often almost imperceptible. The Edison phonograph is an important exception to the general rule; not, of course, the phonograph of the present day with all of its mechanical perfection, but as an instrument capable of recording and reproducing sound. Its invention has been frequently attributed to the discovery that a point attached to a telephone diaphragm would, under the effect of sound-waves, vibrate with sufficient force to prick the finger. The story, though interesting, is not founded on fact; but, if true, it is difficult to see how the discovery in question could have contributed materially to the ultimate accomplishment. To a man of Edison's perception it is absurd to suppose that the effect of the so-called discovery would not have been made as a matter of deduction long before the physical sensation was experienced. As a matter of fact, the invention of the phonograph was the result of pure reason. Some time prior to 1877, Edison had been experimenting on an automatic telegraph in which the letters were formed by embossing strips of paper with the proper arrangement of dots and dashes. By drawing this strip beneath a contact lever, the latter was actuated so as to control the circuits and send the desired signals over the line. It was observed that when the strip was moved very rapidly the vibration of the lever resulted in the production of an audible note. With these facts before him, Edison reasoned that if the paper strip could be imprinted with elevations and depressions representative of sound-waves, they might be caused to actuate a diaphragm so as to reproduce the corresponding sounds. The next step in the line of development was to form the necessary undulations on the strip, and it was then reasoned that original sounds themselves might be utilized to form a graphic record by actuating a diaphragm and causing a cutting or indenting point carried thereby to vibrate in contact with a moving surface, so as to cut or indent the record therein. Strange as it may seem, therefore, and contrary to the general belief, the phonograph was developed backward, the production of the sounds being of prior development to the idea of actually recording them.

Mr. Edison's own account of the invention of the phonograph is intensely interesting. "I was experimenting," he says, "on an automatic method of recording telegraph messages on a disk of paper laid on a revolving platen, exactly the same as the disk talking-machine of to-day. The platen had a spiral groove on its surface, like the disk. Over this was placed a circular disk of paper; an electromagnet with the embossing point connected to an arm travelled over the disk; and any signals given through the magnets were embossed on the disk of paper. If this disk was removed from the machine and put on a similar machine provided with a contact point, the embossed record would cause the signals to be repeated into another wire. The ordinary speed of telegraphic signals is thirty-five to forty words a minute; but with this machine several hundred words were possible.

"From my experiments on the telephone I knew of the power of a diaphragm to take up sound vibrations, as I had made a little toy which, when you recited loudly in the funnel, would work a pawl connected to the diaphragm; and this engaging a ratchet-wheel served to give continuous rotation to a pulley. This pulley was connected by a cord to a little paper toy representing a man sawing wood. Hence, if one shouted: 'Mary had a little lamb,' etc., the paper man would start sawing wood. I reached the conclusion that if I could record the movements of the diaphragm properly, I could cause such record to reproduce the original movements imparted to the diaphragm by the voice, and thus succeed in recording and reproducing the human voice.

"Instead of using a disk I designed a little machine using a cylinder provided with grooves around the surface. Over this was to be placed tinfoil, which easily received and recorded the movements of the diaphragm. A sketch was made, and the piece-work price, $18, was marked on the sketch. I was in the habit of marking the price I would pay on each sketch. If the workman lost, I would pay his regular wages; if he made more than the wages, he kept it. The workman who got the sketch was John Kruesi. I didn't have much faith that it would work, expecting that I might possibly hear a word or so that would give hope of a future for the idea. Kruesi, when he had nearly finished it, asked what it was for. I told him I was going to record talking, and then have the machine talk back. He thought it absurd. However, it was finished, the foil was put on; I then shouted 'Mary had a little lamb,' etc. I adjusted the reproducer, and the machine reproduced it perfectly. I was never so taken aback in my life. Everybody was astonished. I was always afraid of things that worked the first time. Long experience proved that there were great drawbacks found generally before they could be got commercial; but here was something there was no doubt of."

No wonder that honest John Kruesi, as he stood and listened to the marvellous performance of the simple little machine he had himself just finished, ejaculated in an awe-stricken tone: "Mein Gott im Himmel!" And yet he had already seen Edison do a few clever things. No wonder they sat up all night fixing and adjusting it so as to get better and better results--reciting and singing, trying each other's voices, and then listening with involuntary awe as the words came back again and again, just as long as they were willing to revolve the little cylinder with its dotted spiral indentations in the tinfoil under the vibrating stylus of the reproducing diaphragm. It took a little time to acquire the knack of turning the crank steadily while leaning over the recorder to talk into the machine; and there was some deftness required also in fastening down the tinfoil on the cylinder where it was held by a pin running in a longitudinal slot. Paraffined paper appears also to have been experimented with as an impressible material. It is said that Carman, the foreman of the machine shop, had gone the length of wagering Edison a box of cigars that the device would not work. All the world knows that he lost.

The original Edison phonograph thus built by Kruesi is preserved in the South Kensington Museum, London. That repository can certainly have no greater treasure of its kind. But as to its immediate use, the inventor says: "That morning I took it over to New York and walked into the office of the Scientific American, went up to Mr. Beach's desk, and said I had something to show him. He asked what it was. I told him I had a machine that would record and reproduce the human voice. I opened the package, set up the machine and recited, 'Mary had a little lamb,' etc. Then I reproduced it so that it could be heard all over the room. They kept me at it until the crowd got so great Mr. Beach was afraid the floor would collapse; and we were compelled to stop. The papers next morning contained columns. None of the writers seemed to understand how it was done. I tried to explain, it was so very simple, but the results were so surprising they made up their minds probably that they never would understand it--and they didn't.

"I started immediately making several larger and better machines, which I exhibited at Menlo Park to crowds. The Pennsylvania Railroad ran special trains. Washington people telegraphed me to come on. I took a phonograph to Washington and exhibited it in the room of James G. Blaine's niece (Gail Hamilton); and members of Congress and notable people of that city came all day long until late in the evening. I made one break. I recited 'Mary,' etc., and another ditty:

'There was a little girl, who had a little curl Right in the middle of her forehead; And when she was good she was very, very good, But when she was bad she was horrid.'

"It will be remembered that Senator Roscoe Conkling, then very prominent, had a curl of hair on his forehead; and all the caricaturists developed it abnormally. He was very sensitive about the subject. When he came in he was introduced; but being rather deaf, I didn't catch his name, but sat down and started the curl ditty. Everybody tittered, and I was told that Mr. Conkling was displeased. About 11 o'clock at night word was received from President Hayes that he would be very much pleased if I would come up to the White House. I was taken there, and found Mr. Hayes and several others waiting. Among them I remember Carl Schurz, who was playing the piano when I entered the room. The exhibition continued till about 12.30 A.M., when Mrs. Hayes and several other ladies, who had been induced to get up and dress, appeared. I left at 3.30 A.M.

"For a long time some people thought there was trickery. One morning at Menlo Park a gentleman came to the laboratory and asked to see the phonograph. It was Bishop Vincent, who helped Lewis Miller found the Chautauqua I exhibited it, and then he asked if he could speak a few words. I put on a fresh foil and told him to go ahead. He commenced to recite Biblical names with immense rapidity. On reproducing it he said: 'I am satisfied, now. There isn't a man in the United States who could recite those names with the same rapidity.'"

The phonograph was now fairly launched as a world sensation, and a reference to the newspapers of 1878 will show the extent to which it and Edison were themes of universal discussion. Some of the press notices of the period were most amazing--and amusing. As though the real achievements of this young man, barely thirty, were not tangible and solid enough to justify admiration of his genius, the "yellow journalists" of the period began busily to create an "Edison myth," with gross absurdities of assertion and attribution from which the modest subject of it all has not yet ceased to suffer with unthinking people. A brilliantly vicious example of this method of treatment is to be found in the Paris Figaro of that year, which under the appropriate title of "This Astounding Eddison" lay bare before the French public the most startling revelations as to the inventor's life and character. "It should be understood," said this journal, "that Mr. Eddison does not belong to himself. He is the property of the telegraph company which lodges him in New York at a superb hotel; keeps him on a luxurious footing, and pays him a formidable salary so as to be the one to know of and profit by his discoveries. The company has, in the dwelling of Eddison, men in its employ who do not quit him for a moment, at the table, on the street, in the laboratory. So that this wretched man, watched more closely than ever was any malefactor, cannot even give a moment's thought to his own private affairs without one of his guards asking him what he is thinking about." This foolish "blague" was accompanied by a description of Edison's new "aerophone," a steam machine which carried the voice a distance of one and a half miles. "You speak to a jet of vapor. A friend previously advised can answer you by the same method." Nor were American journals backward in this wild exaggeration.

The furor had its effect in stimulating a desire everywhere on the part of everybody to see and hear the phonograph. A small commercial organization was formed to build and exploit the apparatus, and the shops at Menlo Park laboratory were assisted by the little Bergmann shop in New York. Offices were taken for the new enterprise at 203 Broadway, where the Mail and Express building now stands, and where, in a general way, under the auspices of a talented dwarf, C. A. Cheever, the embryonic phonograph and the crude telephone shared rooms and expenses. Gardiner G. Hubbard, father-in-law of Alex. Graham Bell, was one of the stockholders in the Phonograph Company, which paid Edison $10,000 cash and a 20 per cent. royalty. This curious partnership was maintained for some time, even when the Bell Telephone offices were removed to Reade Street, New York, whither the phonograph went also; and was perhaps explained by the fact that just then the ability of the phonograph as a money-maker was much more easily demonstrated than was that of the telephone, still in its short range magneto stage and awaiting development with the aid of the carbon transmitter.

The earning capacity of the phonograph then, as largely now, lay in its exhibition qualities. The royalties from Boston, ever intellectually awake and ready for something new, ran as high as $1800 a week. In New York there was a ceaseless demand for it, and with the aid of Hilbourne L. Roosevelt, a famous organ builder, and uncle of ex-President Roosevelt, concerts were given at which the phonograph was "featured." To manage this novel show business the services of James Redpath were called into requisition with great success. Redpath, famous as a friend and biographer of John Brown, as a Civil War correspondent, and as founder of the celebrated Redpath Lyceum Bureau in Boston, divided the country into territories, each section being leased for exhibition purposes on a basis of a percentage of the "gate money." To 203 Broadway from all over the Union flocked a swarm of showmen, cranks, and particularly of old operators, who, the seedier they were in appearance, the more insistent they were that "Tom" should give them, for the sake of "Auld lang syne," this chance to make a fortune for him and for themselves. At the top of the building was a floor on which these novices were graduated in the use and care of the machine, and then, with an equipment of tinfoil and other supplies, they were sent out on the road. It was a diverting experience while it lasted. The excitement over the phonograph was maintained for many months, until a large proportion of the inhabitants of the country had seen it; and then the show receipts declined and dwindled away. Many of the old operators, taken on out of good-nature, were poor exhibitors and worse accountants, and at last they and the machines with which they had been intrusted faded from sight. But in the mean time Edison had learned many lessons as to this practical side of development that were not forgotten when the renascence of the phonograph began a few years later, leading up to the present enormous and steady demand for both machines and records.

It deserves to be pointed out that the phonograph has changed little in the intervening years from the first crude instruments of 1877-78. It has simply been refined and made more perfect in a mechanical sense. Edison was immensely impressed with its possibilities, and greatly inclined to work upon it, but the coming of the electric light compelled him to throw all his energies for a time into the vast new field awaiting conquest. The original phonograph, as briefly noted above, was rotated by hand, and the cylinder was fed slowly longitudinally by means of a nut engaging a screw thread on the cylinder shaft. Wrapped around the cylinder was a sheet of tinfoil, with which engaged a small chisel-like recording needle, connected adhesively with the centre of an iron diaphragm. Obviously, as the cylinder was turned, the needle followed a spiral path whose pitch depended upon that of the feed screw. Along this path a thread was cut in the cylinder so as to permit the needle to indent the foil readily as the diaphragm vibrated. By rotating the cylinder and by causing the diaphragm to vibrate under the effect of vocal or musical sounds, the needle-like point would form a series of indentations in the foil corresponding to and characteristic of the sound-waves. By now engaging the point with the beginning of the grooved record so formed, and by again rotating the cylinder, the undulations of the record would cause the needle and its attached diaphragm to vibrate so as to effect the reproduction. Such an apparatus was necessarily undeveloped, and was interesting only from a scientific point of view. It had many mechanical defects which prevented its use as a practical apparatus. Since the cylinder was rotated by hand, the speed at which the record was formed would vary considerably, even with the same manipulator, so that it would have been impossible to record and reproduce music satisfactorily; in doing which exact uniformity of speed is essential. The formation of the record in tinfoil was also objectionable from a practical standpoint, since such a record was faint and would be substantially obliterated after two or three reproductions. Furthermore, the foil could not be easily removed from and replaced upon the instrument, and consequently the reproduction had to follow the recording immediately, and the successive tinfoils were thrown away. The instrument was also heavy and bulky. Notwithstanding these objections the original phonograph created, as already remarked, an enormous popular excitement, and the exhibitions were considered by many sceptical persons as nothing more than clever ventriloquism. The possibilities of the instrument as a commercial apparatus were recognized from the very first, and some of the fields in which it was predicted that the phonograph would be used are now fully occupied. Some have not yet been realized. Writing in 1878 in the North American-Review, Mr. Edison thus summed up his own ideas as to the future applications of the new invention:

"Among the many uses to which the phonograph will be applied are the following:

1. Letter writing and all kinds of dictation without the aid of a stenographer.

2. Phonographic books, which will speak to blind people without effort on their part.

3. The teaching of elocution.

4. Reproduction of music.

5. The 'Family Record'--a registry of sayings, reminiscences, etc., by members of a family in their own voices, and of the last words of dying persons.

6. Music-boxes and toys.

7. Clocks that should announce in articulate speech the time for going home, going to meals, etc.

8. The preservation of languages by exact reproduction of the manner of pronouncing.

9. Educational purposes; such as preserving the explanations made by a teacher, so that the pupil can refer to them at any moment, and spelling or other lessons placed upon the phonograph for convenience in committing to memory.

10. Connection with the telephone, so as to make that instrument an auxiliary in the transmission of permanent and invaluable records, instead of being the recipient of momentary and fleeting communication."

Of the above fields of usefulness in which it was expected that the phonograph might be applied, only three have been commercially realized--namely, the reproduction of musical, including vaudeville or talking selections, for which purpose a very large proportion of the phonographs now made is used; the employment of the machine as a mechanical stenographer, which field has been taken up actively only within the past few years; and the utilization of the device for the teaching of languages, for which purpose it has been successfully employed, for example, by the International Correspondence Schools of Scranton, Pennsylvania, for several years. The other uses, however, which were early predicted for the phonograph have not as yet been worked out practically, although the time seems not far distant when its general utility will be widely enlarged. Both dolls and clocks have been made, but thus far the world has not taken them seriously.

The original phonograph, as invented by Edison, remained in its crude and immature state for almost ten years--still the object of philosophical interest, and as a convenient text-book illustration of the effect of sound vibration. It continued to be a theme of curious interest to the imaginative, and the subject of much fiction, while its neglected commercial possibilities were still more or less vaguely referred to. During this period of arrested development, Edison was continuously working on the invention and commercial exploitation of the incandescent lamp. In 1887 his time was comparatively free, and the phonograph was then taken up with renewed energy, and the effort made to overcome its mechanical defects and to furnish a commercial instrument, so that its early promise might be realized. The important changes made from that time up to 1890 converted the phonograph from a scientific toy into a successful industrial apparatus. The idea of forming the record on tinfoil had been early abandoned, and in its stead was substituted a cylinder of wax-like material, in which the record was cut by a minute chisel-like gouging tool. Such a record or phonogram, as it was then called, could be removed from the machine or replaced at any time, many reproductions could be obtained without wearing out the record, and whenever desired the record could be shaved off by a turning-tool so as to present a fresh surface on which a new record could be formed, something like an ancient palimpsest. A wax cylinder having walls less than one-quarter of an inch in thickness could be used for receiving a large number of records, since the maximum depth of the record groove is hardly ever greater than one one-thousandth of an inch. Later on, and as the crowning achievement in the phonograph field, from a commercial point of view, came the duplication of records to the extent of many thousands from a single "master." This work was actively developed between the years 1890 and 1898, and its difficulties may be appreciated when the problem is stated; the copying from a single master of many millions of excessively minute sound-waves having a maximum width of one hundredth of an inch, and a maximum depth of one thousandth of an inch, or less than the thickness of a sheet of tissue-paper. Among the interesting developments of this process was the coating of the original or master record with a homogeneous film of gold so thin that three hundred thousand of these piled one on top of the other would present a thickness of only one inch!

Another important change was in the nature of a reversal of the original arrangement, the cylinder or mandrel carrying the record being mounted in fixed bearings, and the recording or reproducing device being fed lengthwise, like the cutting-tool of a lathe, as the blank or record was rotated. It was early recognized that a single needle for forming the record and the reproduction therefrom was an undesirable arrangement, since the formation of the record required a very sharp cutting-tool, while satisfactory and repeated reproduction suggested the use of a stylus which would result in the minimum wear. After many experiments and the production of a number of types of machines, the present recorders and reproducers were evolved, the former consisting of a very small cylindrical gouging tool having a diameter of about forty thousandths of an inch, and the latter a ball or button-shaped stylus with a diameter of about thirty-five thousandths of an inch. By using an incisor of this sort, the record is formed of a series of connected gouges with rounded sides, varying in depth and width, and with which the reproducer automatically engages and maintains its engagement. Another difficulty encountered in the commercial development of the phonograph was the adjustment of the recording stylus so as to enter the wax-like surface to a very slight depth, and of the reproducer so as to engage exactly the record when formed. The earlier types of machines were provided with separate screws for effecting these adjustments; but considerable skill was required to obtain good results, and great difficulty was experienced in meeting the variations in the wax-like cylinders, due to the warping under atmospheric changes. Consequently, with the early types of commercial phonographs, it was first necessary to shave off the blank accurately before a record was formed thereon, in order that an absolutely true surface might be presented. To overcome these troubles, the very ingenious suggestion was then made and adopted, of connecting the recording and reproducing styluses to their respective diaphragms through the instrumentality of a compensating weight, which acted practically as a fixed support under the very rapid sound vibrations, but which yielded readily to distortions or variations in the wax-like cylinders. By reason of this improvement, it became possible to do away with all adjustments, the mass of the compensating weight causing the recorder to engage the blank automatically to the required depth, and to maintain the reproducing stylus always with the desired pressure on the record when formed. These automatic adjustments were maintained even though the blank or record might be so much out of true as an eighth of an inch, equal to more than two hundred times the maximum depth of the record groove.

Another improvement that followed along the lines adopted by Edison for the commercial development of the phonograph was making the recording and reproducing styluses of sapphire, an extremely hard, non-oxidizable jewel, so that those tiny instruments would always retain their true form and effectively resist wear. Of course, in this work many other things were done that may still be found on the perfected phonograph as it stands to-day, and many other suggestions were made which were contemporaneously adopted, but which were later abandoned. For the curious-minded, reference is made to the records in the Patent Office, which will show that up to 1893 Edison had obtained upward of sixty-five patents in this art, from which his line of thought can be very closely traced. The phonograph of to-day, except for the perfection of its mechanical features, in its beauty of manufacture and design, and in small details, may be considered identical with the machine of 1889, with the exception that with the latter the rotation of the record cylinder was effected by an electric motor.

Its essential use as then contemplated was as a substitute for stenographers, and the most extravagant fancies were indulged in as to utility in that field. To exploit the device commercially, the patents were sold to Philadelphia capitalists, who organized the North American Phonograph Company, through which leases for limited periods were granted to local companies doing business in special territories, generally within the confines of a single State. Under that plan, resembling the methods of 1878, the machines and blank cylinders were manufactured by the Edison Phonograph Works, which still retains its factories at Orange, New Jersey. The marketing enterprise was early doomed to failure, principally because the instruments were not well understood, and did not possess the necessary refinements that would fit them for the special field in which they were to be used. At first the instruments were leased; but it was found that the leases were seldom renewed. Efforts were then made to sell them, but the prices were high--from $100 to $150. In the midst of these difficulties, the chief promoter of the enterprise, Mr. Lippincott, died; and it was soon found that the roseate dreams of success entertained by the sanguine promoters were not to be realized. The North American Phonograph Company failed, its principal creditor being Mr. Edison, who, having acquired the assets of the defunct concern, organized the National Phonograph Company, to which he turned over the patents; and with characteristic energy he attempted again to build up a business with which his favorite and, to him, most interesting invention might be successfully identified. The National Phonograph Company from the very start determined to retire at least temporarily from the field of stenographic use, and to exploit the phonograph for musical purposes as a competitor of the music-box. Hence it was necessary that for such work the relatively heavy and expensive electric motor should be discarded, and a simple spring motor constructed with a sufficiently sensitive governor to permit accurate musical reproduction. Such a motor was designed, and is now used on all phonographs except on such special instruments as may be made with electric motors, as well as on the successful apparatus that has more recently been designed and introduced for stenographic use. Improved factory facilities were introduced; new tools were made, and various types of machines were designed so that phonographs can now be bought at prices ranging from $10 to $200. Even with the changes which were thus made in the two machines, the work of developing the business was slow, as a demand had to be created; and the early prejudice of the public against the phonograph, due to its failure as a stenographic apparatus, had to be overcome. The story of the phonograph as an industrial enterprise, from this point of departure, is itself full of interest, but embraces so many details that it is necessarily given in a separate later chapter. We must return to the days of 1878, when Edison, with at least three first-class inventions to his credit--the quadruplex, the carbon telephone, and the phonograph--had become a man of mark and a "world character."

The invention of the phonograph was immediately followed, as usual, by the appearance of several other incidental and auxiliary devices, some patented, and others remaining simply the application of the principles of apparatus that had been worked out. One of these was the telephonograph, a combination of a telephone at a distant station with a phonograph. The diaphragm of the phonograph mouthpiece is actuated by an electromagnet in the same way as that of an ordinary telephone receiver, and in this manner a record of the message spoken from a distance can be obtained and turned into sound at will. Evidently such a process is reversible, and the phonograph can send a message to the distant receiver.

This idea was brilliantly demonstrated in practice in February, 1889, by Mr. W. J. Hammer, one of Edison's earliest and most capable associates, who carried on telephonographic communication between New York and an audience in Philadelphia. The record made in New York on the Edison phonograph was repeated into an Edison carbon transmitter, sent over one hundred and three miles of circuit, including six miles of underground cable; received by an Edison motograph; repeated by that on to a phonograph; transferred from the phonograph to an Edison carbon transmitter, and by that delivered to the Edison motograph receiver in the enthusiastic lecture-hall, where every one could hear each sound and syllable distinctly. In real practice this spectacular playing with sound vibrations, as if they were lacrosse balls to toss around between the goals, could be materially simplified.

The modern megaphone, now used universally in making announcements to large crowds, particularly at sporting events, is also due to this period as a perfection by Edison of many antecedent devices going back, perhaps, much further than the legendary funnels through which Alexander the Great is said to have sent commands to his outlying forces. The improved Edison megaphone for long-distance work comprised two horns of wood or metal about six feet long, tapering from a diameter of two feet six inches at the mouth to a small aperture provided with ear-tubes. These converging horns or funnels, with a large speaking-trumpet in between them, are mounted on a tripod, and the megaphone is complete. Conversation can be carried on with this megaphone at a distance of over two miles, as with a ship or the balloon. The modern megaphone now employs the receiver form thus introduced as its very effective transmitter, with which the old-fashioned speaking-trumpet cannot possibly compete; and the word "megaphone" is universally applied to the single, side-flaring horn.

A further step in this line brought Edison to the "aerophone," around which the Figaro weaved its fanciful description. In the construction of the aerophone the same kind of tympanum is used as in the phonograph, but the imitation of the human voice, or the transmission of sound, is effected by the quick opening and closing of valves placed within a steam-whistle or an organ-pipe. The vibrations of the diaphragm communicated to the valves cause them to operate in synchronism, so that the vibrations are thrown upon the escaping air or steam; and the result is an instrument with a capacity of magnifying the sounds two hundred times, and of hurling them to great distances intelligibly, like a huge fog-siren, but with immense clearness and penetration. All this study of sound transmission over long distances without wires led up to the consideration and invention of pioneer apparatus for wireless telegraphy--but that also is another chapter.

Yet one more ingenious device of this period must be noted--Edison's vocal engine, the patent application for which was executed in August, 1878, the patent being granted the following December. Reference to this by Edison himself has already been quoted. The "voice-engine," or "phonomotor," converts the vibrations of the voice or of music, acting on the diaphragm, into motion which is utilized to drive some secondary appliance, whether as a toy or for some useful purpose. Thus a man can actually talk a hole through a board.

Somewhat weary of all this work and excitement, and not having enjoyed any cessation from toil, or period of rest, for ten years, Edison jumped eagerly at the opportunity afforded him in the summer of 1878 of making a westward trip. Just thirty years later, on a similar trip over the same ground, he jotted down for this volume some of his reminiscences. The lure of 1878 was the opportunity to try the ability of his delicate tasimeter during the total eclipse of the sun, July 29. His admiring friend, Prof. George F. Barker, of the University of Pennsylvania, with whom he had now been on terms of intimacy for some years, suggested the holiday, and was himself a member of the excursion party that made its rendezvous at Rawlins, Wyoming Territory. Edison had tested his tasimeter, and was satisfied that it would measure down to the millionth part of a degree Fahrenheit. It was just ten years since he had left the West in poverty and obscurity, a penniless operator in search of a job; but now he was a great inventor and famous, a welcome addition to the band of astronomers and physicists assembled to observe the eclipse and the corona.

"There were astronomers from nearly every nation," says Mr. Edison. "We had a special car. The country at that time was rather new; game was in great abundance, and could be seen all day long from the car window, especially antelope. We arrived at Rawlins about 4 P.M. It had a small machine shop, and was the point where locomotives were changed for the next section. The hotel was a very small one, and by doubling up we were barely accommodated. My room-mate was Fox, the correspondent of the New York Herald. After we retired and were asleep a thundering knock on the door awakened us. Upon opening the door a tall, handsome man with flowing hair dressed in western style entered the room. His eyes were bloodshot, and he was somewhat inebriated. He introduced himself as 'Texas Jack'--Joe Chromondo--and said he wanted to see Edison, as he had read about me in the newspapers. Both Fox and I were rather scared, and didn't know what was to be the result of the interview. The landlord requested him not to make so much noise, and was thrown out into the hall. Jack explained that he had just come in with a party which had been hunting, and that he felt fine. He explained, also, that he was the boss pistol-shot of the West; that it was he who taught the celebrated Doctor Carver how to shoot. Then suddenly pointing to a weather-vane on the freight depot, he pulled out a Colt revolver and fired through the window, hitting the vane. The shot awakened all the people, and they rushed in to see who was killed. It was only after I told him I was tired and would see him in the morning that he left. Both Fox and I were so nervous we didn't sleep any that night.

"We were told in the morning that Jack was a pretty good fellow, and was not one of the 'bad men,' of whom they had a good supply. They had one in the jail, and Fox and I went over to see him. A few days before he had held up a Union Pacific train and robbed all the passengers. In the jail also was a half-breed horse-thief. We interviewed the bad man through bars as big as railroad rails. He looked like a 'bad man.' The rim of his ear all around came to a sharp edge and was serrated. His eyes were nearly white, and appeared as if made of glass and set in wrong, like the life-size figures of Indians in the Smithsonian Institution. His face was also extremely irregular. He wouldn't answer a single question. I learned afterward that he got seven years in prison, while the horse-thief was hanged. As horses ran wild, and there was no protection, it meant death to steal one."

This was one interlude among others. "The first thing the astronomers did was to determine with precision their exact locality upon the earth. A number of observations were made, and Watson, of Michigan University, with two others, worked all night computing, until they agreed. They said they were not in error more than one hundred feet, and that the station was twelve miles out of the position given on the maps. It seemed to take an immense amount of mathematics. I preserved one of the sheets, which looked like the time-table of a Chinese railroad. The instruments of the various parties were then set up in different parts of the little town, and got ready for the eclipse which was to occur in three or four days. Two days before the event we all got together, and obtaining an engine and car, went twelve miles farther west to visit the United States Government astronomers at a place called Separation, the apex of the Great Divide, where the waters run east to the Mississippi and west to the Pacific. Fox and I took our Winchester rifles with an idea of doing a little shooting. After calling on the Government people we started to interview the telegraph operator at this most lonely and desolate spot. After talking over old acquaintances I asked him if there was any game around. He said, 'Plenty of jack-rabbits.' These jack-rabbits are a very peculiar species. They have ears about six inches long and very slender legs, about three times as long as those of an ordinary rabbit, and travel at a great speed by a series of jumps, each about thirty feet long, as near as I could judge. The local people called them 'narrow-gauge mules.' Asking the operator the best direction, he pointed west, and noticing a rabbit in a clear space in the sage bushes, I said, 'There is one now.' I advanced cautiously to within one hundred feet and shot. The rabbit paid no attention. I then advanced to within ten feet and shot again--the rabbit was still immovable. On looking around, the whole crowd at the station were watching--and then I knew the rabbit was stuffed! However, we did shoot a number of live ones until Fox ran out of cartridges. On returning to the station I passed away the time shooting at cans set on a pile of tins. Finally the operator said to Fox: 'I have a fine Springfield musket, suppose you try it!' So Fox took the musket and fired. It knocked him nearly over. It seems that the musket had been run over by a handcar, which slightly bent the long barrel, but not sufficiently for an amateur like Fox to notice. After Fox had his shoulder treated with arnica at the Government hospital tent, we returned to Rawlins."

The eclipse was, however, the prime consideration, and Edison followed the example of his colleagues in making ready. The place which he secured for setting up his tasimeter was an enclosure hardly suitable for the purpose, and he describes the results as follows:

"I had my apparatus in a small yard enclosed by a board fence six feet high, at one end there was a house for hens. I noticed that they all went to roost just before totality. At the same time a slight wind arose, and at the moment of totality the atmosphere was filled with thistle-down and other light articles. I noticed one feather, whose weight was at least one hundred and fifty milligrams, rise perpendicularly to the top of the fence, where it floated away on the wind. My apparatus was entirely too sensitive, and I got no results." It was found that the heat from the corona of the sun was ten times the index capacity of the instrument; but this result did not leave the value of the device in doubt. The Scientific American remarked;

"Seeing that the tasimeter is affected by a wider range of etheric undulations than the eye can take cognizance of, and is withal far more acutely sensitive, the probabilities are that it will open up hitherto inaccessible regions of space, and possibly extend the range of aerial knowledge as far beyond the limit obtained by the telescope as that is beyond the narrow reach of unaided vision."

The eclipse over, Edison, with Professor Barker, Major Thornberg, several soldiers, and a number of railroad officials, went hunting about one hundred miles south of the railroad in the Ute country. A few months later the Major and thirty soldiers were ambushed near the spot at which the hunting-party had camped, and all were killed. Through an introduction from Mr. Jay Gould, who then controlled the Union Pacific, Edison was allowed to ride on the cow-catchers of the locomotives. "The different engineers gave me a small cushion, and every day I rode in this manner, from Omaha to the Sacramento Valley, except through the snow-shed on the summit of the Sierras, without dust or anything else to obstruct the view. Only once was I in danger when the locomotive struck an animal about the size of a small cub bear--which I think was a badger. This animal struck the front of the locomotive just under the headlight with great violence, and was then thrown off by the rebound. I was sitting to one side grasping the angle brace, so no harm was done."

This welcome vacation lasted nearly two months; but Edison was back in his laboratory and hard at work before the end of August, gathering up many loose ends, and trying out many thoughts and ideas that had accumulated on the trip. One hot afternoon--August 30th, as shown by the document in the case--Mr. Edison was found by one of the authors of this biography employed most busily in making a mysterious series of tests on paper, using for ink acids that corrugated and blistered the paper where written upon. When interrogated as to his object, he stated that the plan was to afford blind people the means of writing directly to each other, especially if they were also deaf and could not hear a message on the phonograph. The characters which he was thus forming on the paper were high enough in relief to be legible to the delicate touch of a blind man's fingers, and with simple apparatus letters could be thus written, sent, and read. There was certainly no question as to the result obtained at the moment, which was all that was asked; but the Edison autograph thus and then written now shows the paper eaten out by the acid used, although covered with glass for many years. Mr. Edison does not remember that he ever recurred to this very interesting test.

He was, however, ready for anything new or novel, and no record can ever be made or presented that would do justice to a tithe of the thoughts and fancies daily and hourly put upon the rack. The famous note-books, to which reference will be made later, were not begun as a regular series, as it was only the profusion of these ideas that suggested the vital value of such systematic registration. Then as now, the propositions brought to Edison ranged over every conceivable subject, but the years have taught him caution in grappling with them. He tells an amusing story of one dilemma into which his good-nature led him at this period: "At Menlo Park one day, a farmer came in and asked if I knew any way to kill potato-bugs. He had twenty acres of potatoes, and the vines were being destroyed. I sent men out and culled two quarts of bugs, and tried every chemical I had to destroy them. Bisulphide of carbon was found to do it instantly. I got a drum and went over to the potato farm and sprinkled it on the vines with a pot. Every bug dropped dead. The next morning the farmer came in very excited and reported that the stuff had killed the vines as well. I had to pay $300 for not experimenting properly."

During this year, 1878, the phonograph made its way also to Europe, and various sums of money were paid there to secure the rights to its manufacture and exploitation. In England, for example, the Microscopic Company paid $7500 down and agreed to a royalty, while arrangements were effected also in France, Russia, and other countries. In every instance, as in this country, the commercial development had to wait several years, for in the mean time another great art had been brought into existence, demanding exclusive attention and exhaustive toil. And when the work was done the reward was a new heaven and a new earth--in the art of illumination.

XI. THE INVENTION OF THE INCANDESCENT LAMP

IT is possible to imagine a time to come when the hours of work and rest will once more be regulated by the sun. But the course of civilization has been marked by an artificial lengthening of the day, and by a constant striving after more perfect means of illumination. Why mankind should sleep through several hours of sunlight in the morning, and stay awake through a needless time in the evening, can probably only be attributed to total depravity. It is certainly a most stupid, expensive, and harmful habit. In no one thing has man shown greater fertility of invention than in lighting; to nothing does he cling more tenaciously than to his devices for furnishing light. Electricity to-day reigns supreme in the field of illumination, but every other kind of artificial light that has ever been known is still in use somewhere. Toward its light-bringers the race has assumed an attitude of veneration, though it has forgotten, if it ever heard, the names of those who first brightened its gloom and dissipated its darkness. If the tallow candle, hitherto unknown, were now invented, its creator would be hailed as one of the greatest benefactors of the present age.

Up to the close of the eighteenth century, the means of house and street illumination were of two generic kinds--grease and oil; but then came a swift and revolutionary change in the adoption of gas. The ideas and methods of Murdoch and Lebon soon took definite shape, and "coal smoke" was piped from its place of origin to distant points of consumption. As early as 1804, the first company ever organized for gas lighting was formed in London, one side of Pall Mall being lit up by the enthusiastic pioneer, Winsor, in 1807. Equal activity was shown in America, and Baltimore began the practice of gas lighting in 1816. It is true that there were explosions, and distinguished men like Davy and Watt opined that the illuminant was too dangerous; but the "spirit of coal" had demonstrated its usefulness convincingly, and a commercial development began, which, for extent and rapidity, was not inferior to that marking the concurrent adoption of steam in industry and transportation.

Meantime the wax candle and the Argand oil lamp held their own bravely. The whaling fleets, long after gas came into use, were one of the greatest sources of our national wealth. To New Bedford, Massachusetts, alone, some three or four hundred ships brought their whale and sperm oil, spermaceti, and whalebone; and at one time that port was accounted the richest city in the United States in proportion to its population. The ship-owners and refiners of that whaling metropolis were slow to believe that their monopoly could ever be threatened by newer sources of illumination; but gas had become available in the cities, and coal-oil and petroleum were now added to the list of illuminating materials. The American whaling fleet, which at the time of Edison's birth mustered over seven hundred sail, had dwindled probably to a bare tenth when he took up the problem of illumination; and the competition of oil from the ground with oil from the sea, and with coal-gas, had made the artificial production of light cheaper than ever before, when up to the middle of the century it had remained one of the heaviest items of domestic expense. Moreover, just about the time that Edison took up incandescent lighting, water-gas was being introduced on a large scale as a commercial illuminant that could be produced at a much lower cost than coal-gas.

Throughout the first half of the nineteenth century the search for a practical electric light was almost wholly in the direction of employing methods analogous to those already familiar; in other words, obtaining the illumination from the actual consumption of the light-giving material. In the third quarter of the century these methods were brought to practicality, but all may be referred back to the brilliant demonstrations of Sir Humphry Davy at the Royal Institution, circa 1809-10, when, with the current from a battery of two thousand cells, he produced an intense voltaic arc between the points of consuming sticks of charcoal. For more than thirty years the arc light remained an expensive laboratory experiment; but the coming of the dynamo placed that illuminant on a commercial basis. The mere fact that electrical energy from the least expensive chemical battery using up zinc and acids costs twenty times as much as that from a dynamo--driven by steam-engine--is in itself enough to explain why so many of the electric arts lingered in embryo after their fundamental principles had been discovered. Here is seen also further proof of the great truth that one invention often waits for another.

From 1850 onward the improvements in both the arc lamp and the dynamo were rapid; and under the superintendence of the great Faraday, in 1858, protecting beams of intense electric light from the voltaic arc were shed over the waters of the Straits of Dover from the beacons of South Foreland and Dungeness. By 1878 the arc-lighting industry had sprung into existence in so promising a manner as to engender an extraordinary fever and furor of speculation. At the Philadelphia Centennial Exposition of 1876, Wallace-Farmer dynamos built at Ansonia, Connecticut, were shown, with the current from which arc lamps were there put in actual service. A year or two later the work of Charles F. Brush and Edward Weston laid the deep foundation of modern arc lighting in America, securing as well substantial recognition abroad.

Thus the new era had been ushered in, but it was based altogether on the consumption of some material--carbon--in a lamp open to the air. Every lamp the world had ever known did this, in one way or another. Edison himself began at that point, and his note-books show that he made various experiments with this type of lamp at a very early stage. Indeed, his experiments had led him so far as to anticipate in 1875 what are now known as "flaming arcs," the exceedingly bright and generally orange or rose-colored lights which have been introduced within the last few years, and are now so frequently seen in streets and public places. While the arcs with plain carbons are bluish-white, those with carbons containing calcium fluoride have a notable golden glow.

He was convinced, however, that the greatest field of lighting lay in the illumination of houses and other comparatively enclosed areas, to replace the ordinary gas light, rather than in the illumination of streets and other outdoor places by lights of great volume and brilliancy. Dismissing from his mind quickly the commercial impossibility of using arc lights for general indoor illumination, he arrived at the conclusion that an electric lamp giving light by incandescence was the solution of the problem.

Edison was familiar with the numerous but impracticable and commercially unsuccessful efforts that had been previously made by other inventors and investigators to produce electric light by incandescence, and at the time that he began his experiments, in 1877, almost the whole scientific world had pronounced such an idea as impossible of fulfilment. The leading electricians, physicists, and experts of the period had been studying the subject for more than a quarter of a century, and with but one known exception had proven mathematically and by close reasoning that the "Subdivision of the Electric Light," as it was then termed, was practically beyond attainment. Opinions of this nature have ever been but a stimulus to Edison when he has given deep thought to a subject, and has become impressed with strong convictions of possibility, and in this particular case he was satisfied that the subdivision of the electric light--or, more correctly, the subdivision of the electric current--was not only possible but entirely practicable.

It will have been perceived from the foregoing chapters that from the time of boyhood, when he first began to rub against the world, his commercial instincts were alert and predominated in almost all of the enterprises that he set in motion. This characteristic trait had grown stronger as he matured, having received, as it did, fresh impetus and strength from his one lapse in the case of his first patented invention, the vote-recorder. The lesson he then learned was to devote his inventive faculties only to things for which there was a real, genuine demand, and that would subserve the actual necessities of humanity; and it was probably a fortunate circumstance that this lesson was learned at the outset of his career as an inventor. He has never assumed to be a philosopher or "pure scientist."

In order that the reader may grasp an adequate idea of the magnitude and importance of Edison's invention of the incandescent lamp, it will be necessary to review briefly the "state of the art" at the time he began his experiments on that line. After the invention of the voltaic battery, early in the last century, experiments were made which determined that heat could be produced by the passage of the electric current through wires of platinum and other metals, and through pieces of carbon, as noted already, and it was, of course, also observed that if sufficient current were passed through these conductors they could be brought from the lower stage of redness up to the brilliant white heat of incandescence. As early as 1845 the results of these experiments were taken advantage of when Starr, a talented American who died at the early age of twenty-five, suggested, in his English patent of that year, two forms of small incandescent electric lamps, one having a burner made from platinum foil placed under a glass cover without excluding the air; and the other composed of a thin plate or pencil of carbon enclosed in a Torricellian vacuum. These suggestions of young Starr were followed by many other experimenters, whose improvements consisted principally in devices to increase the compactness and portability of the lamp, in the sealing of the lamp chamber to prevent the admission of air, and in means for renewing the carbon burner when it had been consumed. Thus Roberts, in 1852, proposed to cement the neck of the glass globe into a metallic cup, and to provide it with a tube or stop-cock for exhaustion by means of a hand-pump. Lodyguine, Konn, Kosloff, and Khotinsky, between 1872 and 1877, proposed various ingenious devices for perfecting the joint between the metal base and the glass globe, and also provided their lamps with several short carbon pencils, which were automatically brought into circuit successively as the pencils were consumed. In 1876 or 1877, Bouliguine proposed the employment of a long carbon pencil, a short section only of which was in circuit at any one time and formed the burner, the lamp being provided with a mechanism for automatically pushing other sections of the pencil into position between the contacts to renew the burner. Sawyer and Man proposed, in 1878, to make the bottom plate of glass instead of metal, and provided ingenious arrangements for charging the lamp chamber with an atmosphere of pure nitrogen gas which does not support combustion.

These lamps and many others of similar character, ingenious as they were, failed to become of any commercial value, due, among other things, to the brief life of the carbon burner. Even under the best conditions it was found that the carbon members were subject to a rapid disintegration or evaporation, which experimenters assumed was due to the disrupting action of the electric current; and hence the conclusion that carbon contained in itself the elements of its own destruction, and was not a suitable material for the burner of an incandescent lamp. On the other hand, platinum, although found to be the best of all materials for the purpose, aside from its great expense, and not combining with oxygen at high temperatures as does carbon, required to be brought so near the melting-point in order to give light, that a very slight increase in the temperature resulted in its destruction. It was assumed that the difficulty lay in the material of the burner itself, and not in its environment.

It was not realized up to such a comparatively recent date as 1879 that the solution of the great problem of subdivision of the electric current would not, however, be found merely in the production of a durable incandescent electric lamp--even if any of the lamps above referred to had fulfilled that requirement. The other principal features necessary to subdivide the electric current successfully were: the burning of an indefinite number of lights on the same circuit; each light to give a useful and economical degree of illumination; and each light to be independent of all the others in regard to its operation and extinguishment.

The opinions of scientific men of the period on the subject are well represented by the two following extracts--the first, from a lecture at the Royal United Service Institution, about February, 1879, by Mr. (Sir) W. H. Preece, one of the most eminent electricians in England, who, after discussing the question mathematically, said: "Hence the sub-division of the light is an absolute ignis fatuus." The other extract is from a book written by Paget Higgs, LL.D., D.Sc., published in London in 1879, in which he says: "Much nonsense has been talked in relation to this subject. Some inventors have claimed the power to 'indefinitely divide' the electric current, not knowing or forgetting that such a statement is incompatible with the well-proven law of conservation of energy."

"Some inventors," in the last sentence just quoted, probably--indeed, we think undoubtedly--refers to Edison, whose earlier work in electric lighting (1878) had been announced in this country and abroad, and who had then stated boldly his conviction of the practicability of the subdivision of the electrical current. The above extracts are good illustrations, however, of scientific opinions up to the end of 1879, when Mr. Edison's epoch-making invention rendered them entirely untenable. The eminent scientist, John Tyndall, while not sharing these precise views, at least as late as January 17, 1879, delivered a lecture before the Royal Institution on "The Electric Light," when, after pointing out the development of the art up to Edison's work, and showing the apparent hopelessness of the problem, he said: "Knowing something of the intricacy of the practical problem, I should certainly prefer seeing it in Edison's hands to having it in mine."

The reader may have deemed this sketch of the state of the art to be a considerable digression; but it is certainly due to the subject to present the facts in such a manner as to show that this great invention was neither the result of improving some process or device that was known or existing at the time, nor due to any unforeseen lucky chance, nor the accidental result of other experiments. On the contrary, it was the legitimate outcome of a series of exhaustive experiments founded upon logical and original reasoning in a mind that had the courage and hardihood to set at naught the confirmed opinions of the world, voiced by those generally acknowledged to be the best exponents of the art--experiments carried on amid a storm of jeers and derision, almost as contemptuous as if the search were for the discovery of perpetual motion. In this we see the man foreshadowed by the boy who, when he obtained his books on chemistry or physics, did not accept any statement of fact or experiment therein, but worked out every one of them himself to ascertain whether or not they were true.

Although this brings the reader up to the year 1879, one must turn back two years and accompany Edison in his first attack on the electric-light problem. In 1877 he sold his telephone invention (the carbon transmitter) to the Western Union Telegraph Company, which had previously come into possession also of his quadruplex inventions, as already related. He was still busily engaged on the telephone, on acoustic electrical transmission, sextuplex telegraphs, duplex telegraphs, miscellaneous carbon articles, and other inventions of a minor nature. During the whole of the previous year and until late in the summer of 1877, he had been working with characteristic energy and enthusiasm on the telephone; and, in developing this invention to a successful issue, had preferred the use of carbon and had employed it in numerous forms, especially in the form of carbonized paper.

Eighteen hundred and seventy-seven in Edison's laboratory was a veritable carbon year, for it was carbon in some shape or form for interpolation in electric circuits of various kinds that occupied the thoughts of the whole force from morning to night. It is not surprising, therefore, that in September of that year, when Edison turned his thoughts actively toward electric lighting by incandescence, his early experiments should be in the line of carbon as an illuminant. His originality of method was displayed at the very outset, for one of the first experiments was the bringing to incandescence of a strip of carbon in the open air to ascertain merely how much current was required. This conductor was a strip of carbonized paper about an inch long, one-sixteenth of an inch broad, and six or seven one-thousandths of an inch thick, the ends of which were secured to clamps that formed the poles of a battery. The carbon was lighted up to incandescence, and, of course, oxidized and disintegrated immediately. Within a few days this was followed by experiments with the same kind of carbon, but in vacuo by means of a hand-worked air-pump. This time the carbon strip burned at incandescence for about eight minutes. Various expedients to prevent oxidization were tried, such, for instance, as coating the carbon with powdered glass, which in melting would protect the carbon from the atmosphere, but without successful results.

Edison was inclined to concur in the prevailing opinion as to the easy destructibility of carbon, but, without actually settling the point in his mind, he laid aside temporarily this line of experiment and entered a new field. He had made previously some trials of platinum wire as an incandescent burner for a lamp, but left it for a time in favor of carbon. He now turned to the use of almost infusible metals--such as boron, ruthenium, chromium, etc.--as separators or tiny bridges between two carbon points, the current acting so as to bring these separators to a high degree of incandescence, at which point they would emit a brilliant light. He also placed some of these refractory metals directly in the circuit, bringing them to incandescence, and used silicon in powdered form in glass tubes placed in the electric circuit. His notes include the use of powdered silicon mixed with lime or other very infusible non-conductors or semi-conductors. Edison's conclusions on these substances were that, while in some respects they were within the bounds of possibility for the subdivision of the electric current, they did not reach the ideal that he had in mind for commercial results.

Edison's systematized attacks on the problem were two in number, the first of which we have just related, which began in September, 1877, and continued until about January, 1878. Contemporaneously, he and his force of men were very busily engaged day and night on other important enterprises and inventions. Among the latter, the phonograph may be specially mentioned, as it was invented in the late fall of 1877. From that time until July, 1878, his time and attention day and night were almost completely absorbed by the excitement caused by the invention and exhibition of the machine. In July, feeling entitled to a brief vacation after several years of continuous labor, Edison went with the expedition to Wyoming to observe an eclipse of the sun, and incidentally to test his tasimeter, a delicate instrument devised by him for measuring heat transmitted through immense distances of space. His trip has been already described. He was absent about two months. Coming home rested and refreshed, Mr. Edison says: "After my return from the trip to observe the eclipse of the sun, I went with Professor Barker, Professor of Physics in the University of Pennsylvania, and Doctor Chandler, Professor of Chemistry in Columbia College, to see Mr. Wallace, a large manufacturer of brass in Ansonia, Connecticut. Wallace at this time was experimenting on series arc lighting. Just at that time I wanted to take up something new, and Professor Barker suggested that I go to work and see if I could subdivide the electric light so it could be got in small units like gas. This was not a new suggestion, because I had made a number of experiments on electric lighting a year before this. They had been laid aside for the phonograph. I determined to take up the search again and continue it. On my return home I started my usual course of collecting every kind of data about gas; bought all the transactions of the gas-engineering societies, etc., all the back volumes of gas journals, etc. Having obtained all the data, and investigated gas-jet distribution in New York by actual observations, I made up my mind that the problem of the subdivision of the electric current could be solved and made commercial." About the end of August, 1878, he began his second organized attack on the subdivision of the current, which was steadily maintained until he achieved signal victory a year and two months later.

The date of this interesting visit to Ansonia is fixed by an inscription made by Edison on a glass goblet which he used. The legend in diamond scratches runs: "Thomas A. Edison, September 8, 1878, made under the electric light." Other members of the party left similar memorials, which under the circumstances have come to be greatly prized. A number of experiments were witnessed in arc lighting, and Edison secured a small Wallace-Farmer dynamo for his own work, as well as a set of Wallace arc lamps for lighting the Menlo Park laboratory. Before leaving Ansonia, Edison remarked, significantly: "Wallace, I believe I can beat you making electric lights. I don't think you are working in the right direction." Another date which shows how promptly the work was resumed is October 14, 1878, when Edison filed an application for his first lighting patent: "Improvement in Electric Lights." In after years, discussing the work of Wallace, who was not only a great pioneer electrical manufacturer, but one of the founders of the wire-drawing and brass-working industry, Edison said: "Wallace was one of the earliest pioneers in electrical matters in this country. He has done a great deal of good work, for which others have received the credit; and the work which he did in the early days of electric lighting others have benefited by largely, and he has been crowded to one side and forgotten." Associated in all this work with Wallace at Ansonia was Prof. Moses G. Farmer, famous for the introduction of the fire-alarm system; as the discoverer of the self-exciting principle of the modern dynamo; as a pioneer experimenter in the electric-railway field; as a telegraph engineer, and as a lecturer on mines and explosives to naval classes at Newport. During 1858, Farmer, who, like Edison, was a ceaseless investigator, had made a series of studies upon the production of light by electricity, and had even invented an automatic regulator by which a number of platinum lamps in multiple arc could be kept at uniform voltage for any length of time. In July, 1859, he lit up one of the rooms of his house at Salem, Massachusetts, every evening with such lamps, using in them small pieces of platinum and iridium wire, which were made to incandesce by means of current from primary batteries. Farmer was not one of the party that memorable day in September, but his work was known through his intimate connection with Wallace, and there is no doubt that reference was made to it. Such work had not led very far, the "lamps" were hopelessly short-lived, and everything was obviously experimental; but it was all helpful and suggestive to one whose open mind refused no hint from any quarter.

At the commencement of his new attempts, Edison returned to his experiments with carbon as an incandescent burner for a lamp, and made a very large number of trials, all in vacuo. Not only were the ordinary strip paper carbons tried again, but tissue-paper coated with tar and lampblack was rolled into thin sticks, like knitting-needles, carbonized and raised to incandescence in vacuo. Edison also tried hard carbon, wood carbons, and almost every conceivable variety of paper carbon in like manner. With the best vacuum that he could then get by means of the ordinary air-pump, the carbons would last, at the most, only from ten to fifteen minutes in a state of incandescence. Such results were evidently not of commercial value.

Edison then turned his attention in other directions. In his earliest consideration of the problem of subdividing the electric current, he had decided that the only possible solution lay in the employment of a lamp whose incandescing body should have a high resistance combined with a small radiating surface, and be capable of being used in what is called "multiple arc," so that each unit, or lamp, could be turned on or off without interfering with any other unit or lamp. No other arrangement could possibly be considered as commercially practicable.

The full significance of the three last preceding sentences will not be obvious to laymen, as undoubtedly many of the readers of this book may be; and now being on the threshold of the series of Edison's experiments that led up to the basic invention, we interpolate a brief explanation, in order that the reader may comprehend the logical reasoning and work that in this case produced such far-reaching results.

If we consider a simple circuit in which a current is flowing, and include in the circuit a carbon horseshoe-like conductor which it is desired to bring to incandescence by the heat generated by the current passing through it, it is first evident that the resistance offered to the current by the wires themselves must be less than that offered by the burner, because, otherwise current would be wasted as heat in the conducting wires. At the very foundation of the electric-lighting art is the essentially commercial consideration that one cannot spend very much for conductors, and Edison determined that, in order to use wires of a practicable size, the voltage of the current (i.e., its pressure or the characteristic that overcomes resistance to its flow) should be one hundred and ten volts, which since its adoption has been the standard. To use a lower voltage or pressure, while making the solution of the lighting problem a simple one as we shall see, would make it necessary to increase the size of the conducting wires to a prohibitive extent. To increase the voltage or pressure materially, while permitting some saving in the cost of conductors, would enormously increase the difficulties of making a sufficiently high resistance conductor to secure light by incandescence. This apparently remote consideration --weight of copper used--was really the commercial key to the problem, just as the incandescent burner was the scientific key to that problem. Before Edison's invention incandescent lamps had been suggested as a possibility, but they were provided with carbon rods or strips of relatively low resistance, and to bring these to incandescence required a current of low pressure, because a current of high voltage would pass through them so readily as not to generate heat; and to carry a current of low pressure through wires without loss would require wires of enormous size. [8] Having a current of relatively high pressure to contend with, it was necessary to provide a carbon burner which, as compared with what had previously been suggested, should have a very great resistance. Carbon as a material, determined after patient search, apparently offered the greatest hope, but even with this substance the necessary high resistance could be obtained only by making the burner of extremely small cross-section, thereby also reducing its radiating surface. Therefore, the crucial point was the production of a hair-like carbon filament, with a relatively great resistance and small radiating surface, capable of withstanding mechanical shock, and susceptible of being maintained at a temperature of over two thousand degrees for a thousand hours or more before breaking. And this filamentary conductor required to be supported in a vacuum chamber so perfectly formed and constructed that during all those hours, and subjected as it is to varying temperatures, not a particle of air should enter to disintegrate the filament. And not only so, but the lamp after its design must not be a mere laboratory possibility, but a practical commercial article capable of being manufactured at low cost and in large quantities. A statement of what had to be done in those days of actual as well as scientific electrical darkness is quite sufficient to explain Tyndall's attitude of mind in preferring that the problem should be in Edison's hands rather than in his own. To say that the solution of the problem lay merely in reducing the size of the carbon burner to a mere hair, is to state a half-truth only; but who, we ask, would have had the temerity even to suggest that such an attenuated body could be maintained at a white heat, without disintegration, for a thousand hours? The solution consisted not only in that, but in the enormous mass of patiently worked-out details--the manufacture of the filaments, their uniform carbonization, making the globes, producing a perfect vacuum, and countless other factors, the omission of any one of which would probably have resulted eventually in failure.

[Footnote 8: As a practical illustration of these facts it was calculated by Professor Barker, of the University of Pennsylvania (after Edison had invented the incandescent lamp), that if it should cost $100,000 for copper conductors to supply current to Edison lamps in a given area, it would cost about $200,000,000 for copper conductors for lighting the same area by lamps of the earlier experimenters--such, for instance, as the lamp invented by Konn in 1875. This enormous difference would be accounted for by the fact that Edison's lamp was one having a high resistance and relatively small radiating surface, while Konn's lamp was one having a very low resistance and large radiating surface.]

Continuing the digression one step farther in order to explain the term "multiple arc," it may be stated that there are two principal systems of distributing electric current, one termed "series," and the other "multiple arc." The two are illustrated, diagrammatically, side by side, the arrows indicating flow of current. The series system, it will be seen, presents one continuous path for the current. The current for the last lamp must pass through the first and all the intermediate lamps. Hence, if any one light goes out, the continuity of the path is broken, current cannot flow, and all the lamps are extinguished unless a loop or by-path is provided. It is quite obvious that such a system would be commercially impracticable where small units, similar to gas jets, were employed. On the other hand, in the multiple-arc system, current may be considered as flowing in two parallel conductors like the vertical sides of a ladder, the ends of which never come together. Each lamp is placed in a separate circuit across these two conductors, like a rung in the ladder, thus making a separate and independent path for the current in each case. Hence, if a lamp goes out, only that individual subdivision, or ladder step, is affected; just that one particular path for the current is interrupted, but none of the other lamps is interfered with. They remain lighted, each one independent of the other. The reader will quite readily understand, therefore, that a multiple-arc system is the only one practically commercial where electric light is to be used in small units like those of gas or oil.

Such was the nature of the problem that confronted Edison at the outset. There was nothing in the whole world that in any way approximated a solution, although the most brilliant minds in the electrical art had been assiduously working on the subject for a quarter of a century preceding. As already seen, he came early to the conclusion that the only solution lay in the use of a lamp of high resistance and small radiating surface, and, with characteristic fervor and energy, he attacked the problem from this standpoint, having absolute faith in a successful outcome. The mere fact that even with the successful production of the electric lamp the assault on the complete problem of commercial lighting would hardly be begun did not deter him in the slightest. To one of Edison's enthusiastic self-confidence the long vista of difficulties ahead--we say it in all sincerity--must have been alluring.

After having devoted several months to experimental trials of carbon, at the end of 1878, as already detailed, he turned his attention to the platinum group of metals and began a series of experiments in which he used chiefly platinum wire and iridium wire, and alloys of refractory metals in the form of wire burners for incandescent lamps. These metals have very high fusing-points, and were found to last longer than the carbon strips previously used when heated up to incandescence by the electric current, although under such conditions as were then possible they were melted by excess of current after they had been lighted a comparatively short time, either in the open air or in such a vacuum as could be obtained by means of the ordinary air-pump.

Nevertheless, Edison continued along this line of experiment with unremitting vigor, making improvement after improvement, until about April, 1879, he devised a means whereby platinum wire of a given length, which would melt in the open air when giving a light equal to four candles, would emit a light of twenty-five candle-power without fusion. This was accomplished by introducing the platinum wire into an all-glass globe, completely sealed and highly exhausted of air, and passing a current through the platinum wire while the vacuum was being made. In this, which was a new and radical invention, we see the first step toward the modern incandescent lamp. The knowledge thus obtained that current passing through the platinum during exhaustion would drive out occluded gases (i.e., gases mechanically held in or upon the metal), and increase the infusibility of the platinum, led him to aim at securing greater perfection in the vacuum, on the theory that the higher the vacuum obtained, the higher would be the infusibility of the platinum burner. And this fact also was of the greatest importance in making successful the final use of carbon, because without the subjection of the carbon to the heating effect of current during the formation of the vacuum, the presence of occluded gases would have been a fatal obstacle.

Continuing these experiments with most fervent zeal, taking no account of the passage of time, with an utter disregard for meals, and but scanty hours of sleep snatched reluctantly at odd periods of the day or night, Edison kept his laboratory going without cessation. A great variety of lamps was made of the platinum-iridium type, mostly with thermal devices to regulate the temperature of the burner and prevent its being melted by an excess of current. The study of apparatus for obtaining more perfect vacua was unceasingly carried on, for Edison realized that in this there lay a potent factor of ultimate success. About August he had obtained a pump that would produce a vacuum up to about the one-hundred-thousandth part of an atmosphere, and some time during the next month, or beginning of October, had obtained one that would produce a vacuum up to the one-millionth part of an atmosphere. It must be remembered that the conditions necessary for MAINTAINING this high vacuum were only made possible by his invention of the one-piece all-glass globe, in which all the joints were hermetically sealed during its manufacture into a lamp, whereby a high vacuum could be retained continuously for any length of time.

In obtaining this perfection of vacuum apparatus, Edison realized that he was approaching much nearer to a solution of the problem. In his experiments with the platinum-iridium lamps, he had been working all the time toward the proposition of high resistance and small radiating surface, until he had made a lamp having thirty feet of fine platinum wire wound upon a small bobbin of infusible material; but the desired economy, simplicity, and durability were not obtained in this manner, although at all times the burner was maintained at a critically high temperature. After attaining a high degree of perfection with these lamps, he recognized their impracticable character, and his mind reverted to the opinion he had formed in his early experiments two years before--viz., that carbon had the requisite resistance to permit a very simple conductor to accomplish the object if it could be used in the form of a hair-like "filament," provided the filament itself could be made sufficiently homogeneous. As we have already seen, he could not use carbon successfully in his earlier experiments, for the strips of carbon he then employed, although they were much larger than "filaments," would not stand, but were consumed in a few minutes under the imperfect conditions then at his command.

Now, however, that he had found means for obtaining and maintaining high vacua, Edison immediately went back to carbon, which from the first he had conceived of as the ideal substance for a burner. His next step proved conclusively the correctness of his old deductions. On October 21, 1879, after many patient trials, he carbonized a piece of cotton sewing-thread bent into a loop or horseshoe form, and had it sealed into a glass globe from which he exhausted the air until a vacuum up to one-millionth of an atmosphere was produced. This lamp, when put on the circuit, lighted up brightly to incandescence and maintained its integrity for over forty hours, and lo! the practical incandescent lamp was born. The impossible, so called, had been attained; subdivision of the electric-light current was made practicable; the goal had been reached; and one of the greatest inventions of the century was completed. Up to this time Edison had spent over $40,000 in his electric-light experiments, but the results far more than justified the expenditure, for with this lamp he made the discovery that the FILAMENT of carbon, under the conditions of high vacuum, was commercially stable and would stand high temperatures without the disintegration and oxidation that took place in all previous attempts that he knew of for making an incandescent burner out of carbon. Besides, this lamp possessed the characteristics of high resistance and small radiating surface, permitting economy in the outlay for conductors, and requiring only a small current for each unit of light--conditions that were absolutely necessary of fulfilment in order to accomplish commercially the subdivision of the electric-light current.

This slender, fragile, tenuous thread of brittle carbon, glowing steadily and continuously with a soft light agreeable to the eyes, was the tiny key that opened the door to a world revolutionized in its interior illumination. It was a triumphant vindication of Edison's reasoning powers, his clear perceptions, his insight into possibilities, and his inventive faculty, all of which had already been productive of so many startling, practical, and epoch-making inventions. And now he had stepped over the threshold of a new art which has since become so world-wide in its application as to be an integral part of modern human experience. [9]

[Footnote 9: The following extract from Walker on Patents (4th edition) will probably be of interest to the reader:

"Sec. 31a. A meritorious exception, to the rule of the last section, is involved in the adjudicated validity of the Edison incandescent-light patent. The carbon filament, which constitutes the only new part of the combination of the second claim of that patent, differs from the earlier carbon burners of Sawyer and Man, only in having a diameter of one- sixty-fourth of an inch or less, whereas the burners of Sawyer and Man had a diameter of one-thirty-second of an inch or more. But that reduction of one-half in diameter increased the resistance of the burner FOURFOLD, and reduced its radiating surface TWOFOLD, and thus increased eightfold, its ratio of resistance to radiating surface. That eightfold increase of proportion enabled the resistance of the conductor of electricity from the generator to the burner to be increased eightfold, without any increase of percentage of loss of energy in that conductor, or decrease of percentage of development of heat in the burner; and thus enabled the area of the cross-section of that conductor to be reduced eightfold, and thus to be made with one-eighth of the amount of copper or other metal, which would be required if the reduction of diameter of the burner from one-thirty- second to one-sixty-fourth of an inch had not been made. And that great reduction in the size and cost of conductors, involved also a great difference in the composition of the electric energy employed in the system; that difference consisting in generating the necessary amount of electrical energy with comparatively high electromotive force, and comparatively low current, instead of contrariwise. For this reason, the use of carbon filaments, one-sixty-fourth of an inch in diameter or less, instead of carbon burners one- thirty-second of an inch in diameter or more, not only worked an enormous economy in conductors, but also necessitated a great change in generators, and did both according to a philosophy, which Edison was the first to know, and which is stated in this paragraph in its simplest form and aspect, and which lies at the foundation of the incandescent electric lighting of the world."]

No sooner had the truth of this new principle been established than the work to establish it firmly and commercially was carried on more assiduously than ever. The next immediate step was a further investigation of the possibilities of improving the quality of the carbon filament. Edison had previously made a vast number of experiments with carbonized paper for various electrical purposes, with such good results that he once more turned to it and now made fine filament-like loops of this material which were put into other lamps. These proved even more successful (commercially considered) than the carbonized thread--so much so that after a number of such lamps had been made and put through severe tests, the manufacture of lamps from these paper carbons was begun and carried on continuously. This necessitated first the devising and making of a large number of special tools for cutting the carbon filaments and for making and putting together the various parts of the lamps. Meantime, great excitement had been caused in this country and in Europe by the announcement of Edison's success. In the Old World, scientists generally still declared the impossibility of subdividing the electric-light current, and in the public press Mr. Edison was denounced as a dreamer. Other names of a less complimentary nature were applied to him, even though his lamp were actually in use, and the principle of commercial incandescent lighting had been established.

Between October 21, 1879, and December 21, 1879, some hundreds of these paper-carbon lamps had been made and put into actual use, not only in the laboratory, but in the streets and several residences at Menlo Park, New Jersey, causing great excitement and bringing many visitors from far and near. On the latter date a full-page article appeared in the New York Herald which so intensified the excited feeling that Mr. Edison deemed it advisable to make a public exhibition. On New Year's Eve, 1879, special trains were run to Menlo Park by the Pennsylvania Railroad, and over three thousand persons took advantage of the opportunity to go out there and witness this demonstration for themselves. In this great crowd were many public officials and men of prominence in all walks of life, who were enthusiastic in their praises.

In the mean time, the mind that conceived and made practical this invention could not rest content with anything less than perfection, so far as it could be realized. Edison was not satisfied with paper carbons. They were not fully up to the ideal that he had in mind. What he sought was a perfectly uniform and homogeneous carbon, one like the "One-Hoss Shay," that had no weak spots to break down at inopportune times. He began to carbonize everything in nature that he could lay hands on. In his laboratory note-books are innumerable jottings of the things that were carbonized and tried, such as tissue-paper, soft paper, all kinds of cardboards, drawing-paper of all grades, paper saturated with tar, all kinds of threads, fish-line, threads rubbed with tarred lampblack, fine threads plaited together in strands, cotton soaked in boiling tar, lamp-wick, twine, tar and lampblack mixed with a proportion of lime, vulcanized fibre, celluloid, boxwood, cocoanut hair and shell, spruce, hickory, baywood, cedar and maple shavings, rosewood, punk, cork, bagging, flax, and a host of other things. He also extended his searches far into the realms of nature in the line of grasses, plants, canes, and similar products, and in these experiments at that time and later he carbonized, made into lamps, and tested no fewer than six thousand different species of vegetable growths.

The reasons for such prodigious research are not apparent on the face of the subject, nor is this the occasion to enter into an explanation, as that alone would be sufficient to fill a fair-sized book. Suffice it to say that Edison's omnivorous reading, keen observation, power of assimilating facts and natural phenomena, and skill in applying the knowledge thus attained to whatever was in hand, now came into full play in determining that the results he desired could only be obtained in certain directions.

At this time he was investigating everything with a microscope, and one day in the early part of 1880 he noticed upon a table in the laboratory an ordinary palm-leaf fan. He picked it up and, looking it over, observed that it had a binding rim made of bamboo, cut from the outer edge of the cane; a very long strip. He examined this, and then gave it to one of his assistants, telling him to cut it up and get out of it all the filaments he could, carbonize them, put them into lamps, and try them. The results of this trial were exceedingly successful, far better than with anything else thus far used; indeed, so much so, that after further experiments and microscopic examinations Edison was convinced that he was now on the right track for making a thoroughly stable, commercial lamp; and shortly afterward he sent a man to Japan to procure further supplies of bamboo. The fascinating story of the bamboo hunt will be told later; but even this bamboo lamp was only one item of a complete system to be devised--a system that has since completely revolutionized the art of interior illumination.

Reference has been made in this chapter to the preliminary study that Edison brought to bear on the development of the gas art and industry. This study was so exhaustive that one can only compare it to the careful investigation made in advance by any competent war staff of the elements of strength and weakness, on both sides, in a possible campaign. A popular idea of Edison that dies hard, pictures a breezy, slap-dash, energetic inventor arriving at new results by luck and intuition, making boastful assertions and then winning out by mere chance. The native simplicity of the man, the absence of pose and ceremony, do much to strengthen this notion; but the real truth is that while gifted with unusual imagination, Edison's march to the goal of a new invention is positively humdrum and monotonous in its steady progress. No one ever saw Edison in a hurry; no one ever saw him lazy; and that which he did with slow, careful scrutiny six months ago, he will be doing with just as much calm deliberation of research six months hence--and six years hence if necessary. If, for instance, he were asked to find the most perfect pebble on the Atlantic shore of New Jersey, instead of hunting here, there, and everywhere for the desired object, we would no doubt find him patiently screening the entire beach, sifting out the most perfect stones and eventually, by gradual exclusion, reaching the long-sought-for pebble; and the mere fact that in this search years might be taken, would not lessen his enthusiasm to the slightest extent.

In the "prospectus book" among the series of famous note-books, all the references and data apply to gas. The book is numbered 184, falls into the period now dealt with, and runs along casually with items spread out over two or three years. All these notes refer specifically to "Electricity vs. Gas as General Illuminants," and cover an astounding range of inquiry and comment. One of the very first notes tells the whole story: "Object, Edison to effect exact imitation of all done by gas, so as to replace lighting by gas by lighting by electricity. To improve the illumination to such an extent as to meet all requirements of natural, artificial, and commercial conditions." A large programme, but fully executed! The notes, it will be understood, are all in Edison's handwriting. They go on to observe that "a general system of distribution is the only possible means of economical illumination," and they dismiss isolated-plant lighting as in mills and factories as of so little importance to the public--"we shall leave the consideration of this out of this book." The shrewd prophecy is made that gas will be manufactured less for lighting, as the result of electrical competition, and more and more for heating, etc., thus enlarging its market and increasing its income. Comment is made on kerosene and its cost, and all kinds of general statistics are jotted down as desirable. Data are to be obtained on lamp and dynamo efficiency, and "Another review of the whole thing as worked out upon pure science principles by Rowland, Young, Trowbridge; also Rowland on the possibilities and probabilities of cheaper production by better manufacture--higher incandescence without decrease of life of lamps." Notes are also made on meters and motors. "It doesn't matter if electricity is used for light or for power"; while small motors, it is observed, can be used night or day, and small steam-engines are inconvenient. Again the shrewd comment: "Generally poorest district for light, best for power, thus evening up whole city--the effect of this on investment."

It is pointed out that "Previous inventions failed--necessities for commercial success and accomplishment by Edison. Edison's great effort--not to make a large light or a blinding light, but a small light having the mildness of gas." Curves are then called for of iron and copper investment--also energy line--curves of candle-power and electromotive force; curves on motors; graphic representation of the consumption of gas January to December; tables and formulae; representations graphically of what one dollar will buy in different kinds of light; "table, weight of copper required different distance, 100-ohm lamp, 16 candles"; table with curves showing increased economy by larger engine, higher power, etc. There is not much that is dilettante about all this. Note is made of an article in April, 1879, putting the total amount of gas investment in the whole world at that time at $1,500,000,000; which is now (1910) about the amount of the electric-lighting investment in the United States. Incidentally a note remarks: "So unpleasant is the effect of the products of gas that in the new Madison Square Theatre every gas jet is ventilated by special tubes to carry away the products of combustion." In short, there is no aspect of the new problem to which Edison failed to apply his acutest powers; and the speed with which the new system was worked out and introduced was simply due to his initial mastery of all the factors in the older art. Luther Stieringer, an expert gas engineer and inventor, whose services were early enlisted, once said that Edison knew more about gas than any other man he had ever met. The remark is an evidence of the kind of preparation Edison gave himself for his new task.