Lacking carfare, Tesla had to walk the several miles to his friend's home. The first person he spoke to, seeking traveling directions, was a policeman, a gruff individual. The way he supplied the information suggested to Tesla that he was willing to start a fight on the subject. Although Tesla spoke English very well, all he understood of the policeman's lingo was the direction in which he pointed his club.

While walking in what he believed was the right direction, wondering how he would be able to contrive a meal and lodgings out of four cents should he be unable to locate his friend, he passed a shop in which he could see a man working on an electrical machine that seemed to him familiar. He entered just as the man was about to give up as impossible the task of repairing the device.

"Let me do it," said Tesla, "I will make it operate." And without more ado he tackled the job. It proved to be a difficult task but eventually the machine was working again.

"I need a man like you to handle these blankety-blank foreign machines," said the man. "Do you want a job?"

Tesla thanked him and told him he was on his way to another job, whereupon the man handed him twenty dollars. Tesla had expected no compensation for doing what he considered a slight favor, and said so, but the man insisted his work was worth that much, and he was glad to pay it. Never was Tesla more thankful for a windfall. He was now assured of food and lodgings for the time being. With the aid of walking directions, this time more graciously given, he located his friend and was a guest at his home overnight. The next day he went to Edison's New York headquarters, then on South Fifth Avenue (now West Broadway).

The introduction by Mr. Batchellor gave him ready access to Mr. Edison, who was busily engaged in problems in connection with his new generating station and electric-light system--the former located in downtown Pearl Street and serving a relatively small radius of territory.

Tesla was favorably impressed by Edison on their first meeting. He marveled that a man so limited in education could accomplish so much in so technical a field as electricity. It caused Tesla to wonder if all the time he had spent in gaining an education of very broad scope had not been wasted. Would he have been further ahead if he had started his practical work on the basis of experience, as Edison had done? He definitely decided, however, before many days had passed, that the time and effort he had spent on his education constituted the wisest kind of an investment.

Edison, for his part, was none too favorably impressed by Tesla. Edison was an inventor who got his results by trial-and-error methods. Tesla calculated everything mentally and solved his problems before doing any "work" on them. As a result, the two great men spoke an entirely different technical language. There was one more very important difference. Edison belonged to the direct-current and Tesla to the alternating-current school of thought. The electricians of that day could, and did, become highly emotional over their differences of opinion on this subject. Discussions roused all the fervor of a religious or political debate, and everything unpleasant was associated with the adherents on the other side of the discussion. The least unpleasant thought applied to an opponent was that he was of a low order of mentality. When Tesla enthusiastically described his polyphase system and told Edison he believed alternating-current was the only practical kind of current to use in a power-and-lighting system, Edison laughed. Edison was using direct current in his system. He told Tesla very bluntly he was not interested in alternating-current; there was no future to it and anyone who dabbled in that field was wasting his time; and besides, it was a deadly current whereas direct current was safe. Tesla did not yield any ground in the discussion--nor could he make any progress in his effort to get Edison to listen to a presentation of his polyphase power system. On technical grounds, they were worlds apart.

Nevertheless, because of Batchellor's statement on the valuable work he had done on the Edison direct-current machines in Europe, Tesla was, without much formality, given a job on Edison's staff--doing minor routine work. A few weeks later he had an opportunity to demonstrate his ability. Edison had installed one of his electric-light plants on the steamship Oregon, the fastest and most up-to-date passenger ship of that time. The installation worked well for many months but finally both dynamos went out of commission. It was impossible to remove the dynamos and install new ones, so it was necessary to repair the old ones in some way--but this, Edison had been told, was impossible without taking them to the shop. The scheduled sailing date of the ship had passed and Edison was being placed in an embarrassing position over the accumulating days of delay caused by his machines.

Edison asked Tesla if he would go to the ship and see what could be done about the situation. This was in the afternoon. Taking such instruments as he thought he would need, Tesla went aboard the Oregon. He found that short circuits had caused some of the armature coils to be burned out; and open circuits had developed elsewhere on the machines.

Calling on members of the crew to assist him, Tesla worked through the night and by 4 am had both machines running as well as they did the day they were newly installed. Walking back to the shop on lower Fifth Avenue at 5 am, in the dim early dawn he met a group of men just leaving. In it were Edison, Batchellor, who had returned from Paris in the meantime, and several others who had finished their night's work and were returning to their homes.

"Here is our Parisian running around nights," said Edison.

"Am just coming back from the Oregon," Tesla replied. "Both machines are operating."

Edison, amazed, shook his head and turned away without another word. On rejoining the group he said to Batchellor, loud enough for the keen-eared Tesla to hear him, "Batchellor, this is a damn good man."

Thereafter Tesla's status on the staff was raised several levels and he was given closer contact with design and operating problems. He found the work interesting and applied himself to it more than eighteen hours a day, from 10:30 am until 5 am, every day including Sundays. Edison, observing his industry, told him, "I have had many hard-working assistants but you take the cake." Tesla observed many ways in which the dynamos could be improved in design to operate more efficiently. He outlined his plan to Edison, and stressed the increased output and lower cost of operating that would result from the changes he suggested. Edison, quick to appreciate the value of increased efficiency, replied, "There's fifty thousand dollars in it for you if you can do it."

Tesla designed twenty-four types of dynamos, eliminating the long-core field magnets then in use and substituting the more efficient short cores, and provided some automatic controls, on which patents were taken out. Months later, when the task was finished, and some of the new machines built and tested and found measuring up to his promises, Tesla asked to be paid the $50,000. Edison replied, "Tesla, you don't understand our American humor." Tesla was shocked to discover that what he thought was a specific promise was being tossed aside merely as a standard practical joke of the day. He received not a penny of compensation from the new designs and inventions, or for the tremendous amount of overtime, beyond the none too generous weekly pay. He resigned his job immediately. This was in the spring of 1885.

In the period of less than a year which he spent with Edison, Tesla had developed a good reputation in electrical circles; so when he was free he was offered an opportunity to capitalize on it. A group of promoters offered to form a company under his name. This looked like a possible chance to bring out his alternating-current system, and he eagerly entered into the project. But when he urged his plan, the promoters informed him they were not interested in alternating-current. What they wanted him to develop was a practical arc light for street and factory illumination. In about a year he developed the desired lamp, took out several patents on his invention, and its manufacture and use were under way.

From a technical point of view the venture was a success, but Tesla himself suffered another painful financial experience in connection with it. He had been paid a comparatively small salary during the period of development. According to the agreement, he was to receive his principal compensation in the form of shares of stock in the company. He received a beautifully engraved stock certificate, and then, by some manipulations he did not understand, he was forced out of the company and aspersions were cast upon his ability as an engineer and an inventor. When he sought to convert the certificate into cash, he found that the shares of newly organized companies of undemonstrated power to earn dividends possess very slight value. His opinion of financial men in both the Old World and the New was taking on a decidedly uncomplimentary bias.

Now came the most unpleasant experience of Tesla's life. He was without a source of income, and from the spring of 1886 to the spring of 1887 he was forced to work as a day laborer. "I lived," he said, "through a year of terrible heartaches and bitter tears, my suffering being intensified by material want." Business conditions were none too good in the country. Not only did he have difficulty in getting anyone to listen to his alternating-current project, but even in his effort to earn room and board as a laborer he had tremendous competition, and found it none too easy to secure the most menial tasks at almost starvation wages. He would never discuss this period of his life, probably because it was so unpleasant that he banished all thoughts of it from his memory. Some electrical repair work and even ditch digging at $2 a day were among the jobs he tackled. He resented the utter waste of his abilities more than the personal degradation involved. His education, he said, seemed a mockery.

During the winter of early 1887, while engaged in ditch digging, he attracted the attention of the foreman of the gang who, too, was being forced by circumstances to work below his accustomed level. The foreman was impressed by Tesla's story of his inventions and his great hopes for his alternating-current system. Through this foreman, Tesla said, he was introduced to Mr. A. K. Brown of the Western Union Telegraph Company who put up some of his own money and interested a friend in joining him in Tesla's project.

These two gentlemen organized and financed the Tesla Electric Company, and in April, 1887, established a laboratory at 33-35 South Fifth Avenue (now West Broadway), near Bleecker Street, not far from the shop of the Edison Company. Edison had turned down Tesla's alternating-current idea--and now Tesla was his neighbor with a laboratory of his own, starting to develop the competing idea. Within this small area was to be fought the great battle of the electrical industry over the question of whether direct or alternating current should be used. Edison, already famous, was wholeheartedly committed to direct current; his powerhouses were operating in several cities and, in addition, he had the support of the famous financier, J. P. Morgan. Tesla, on the other hand, was unknown and had only very modest financial support. The direct current was technically simple, whereas alternating-current was technically complex. Tesla knew, however, that in these complexities were unlimited possibilities for usefulness.

Tesla's dark days were over. Yet he was soon to discover that the acceptance or rejection of the alternating-current system was not based on technical facts but upon financial considerations, emotional reactions and prejudices, and that human nature was a bigger factor than scientific truths. Nevertheless, in a short time, he would see some of his greatest hopes and dreams realized, and success in large measure reward his efforts.

Once he had achieved something resembling fair conditions under which to carry on his work, the rising star of Tesla's genius shot across the electrical heavens like a meteor. As soon as the newly organized Tesla Electric Company opened its South Fifth Avenue laboratories he started the construction of a variety of pieces of dynamo electric machinery. It was not necessary for him to do any calculating, or work out blueprints. Everything was crystal clear in his mind down to the finest detail of each piece of apparatus. As a result he very quickly produced the working units with which he demonstrated the principles of his polyphase alternating-current system. The single piece of apparatus he had built while in Strassburg, the first model of the induction motor, supplied the physical proof he needed that all the remainder of his calculations were correct.

The apparatuses built in his new laboratory were identical with those which he conceived during the two months in Budapest following the remarkable revelation of the principle of the revolving magnetic field. He did not make the slightest change, he said, in the machines he had mentally constructed at that time. When the machines were physically constructed not one of them failed to operate as he had anticipated. Five years had elapsed since he evolved the designs. In the meantime he had not committed a line to paper--yet he had remembered perfectly every last detail.

Tesla produced as rapidly as the machines could be constructed three complete systems of alternating-current machinery--for single-phase, two-phase and three-phase currents--and made experiments with four- and six-phase currents. In each of the three principal systems he produced the dynamos for generating the currents, the motors for producing power from them and transformers for raising and reducing the voltages, as well as a variety of devices for automatically controlling the machinery. He not only produced the three systems but provided methods by which they could be interconnected, and modifications providing a variety of means of using each of the systems. A few months after opening the laboratory he submitted his two-phase motor to Prof. W. A. Anthony, of Cornell University, for testing. Prof. Anthony reported that it had an efficiency equal to that of the best direct-current motors.

Tesla now not only constructed the machines which he visualized but he worked out the basic mathematical theory underlying all of the apparatus. The mathematical theory was so basic that it covered not only the principles applying to machinery for operation at 60 cycles per second, which is the frequency now in standard use, but applied equally well to the whole range of low- and high-frequency currents. With Edison direct current, it had not been found practicable to work with potentials higher than 220 volts on distribution systems; but with alternating-current it was possible to produce and transmit currents of many thousands of volts, thus permitting economical distribution, and these could be reduced to the lower voltages for customer use.

Tesla sought to obtain a single patent covering the entire system and all of its constituent dynamos, transformers, distribution systems and motors. His patent attorneys, Duncan, Curtis & Page, filed the application for this patent October 12, 1887, six months after the laboratory opened and five and a half years after Tesla had made his rotary magnetic-field invention.

The Patent Office, however, objected to considering such an "omnibus" application and insisted it be broken down to seven separate inventions, with individual applications filed on each. Two groups of separate applications were filed, on November 30 and December 23 respectively. These inventions were so original and covered such a virgin field of electrical science that they encountered practically no difficulties in the Patent Office and within about six months the patents were issued. (They were numbered 381,968; 381,969; 381,970; 382,279; 382,280; 382,281 and 382,282. These covered his single and polyphase motors, his distribution system and polyphase transformers. In April of the following year, 1888, he applied for and was later granted five more patents, which included the four-and three-wire three-phase systems. These were numbered 390,413; 390,414; 390,415; 390,721; and 390,820. Within the year he applied for and was granted eighteen more: 401,520; 405,858; 405,859; 416,191; 416,192; 416,193; 416,194; 416,195; 418,248; 424,036; 433,700; 433.701; 433,702; 433,703; 445,207; 445,067; 459,772 and 464,666.)

As a succession of fundamental patents started to issue from the Patent Office to Tesla, the attention of the electrical engineering profession was drawn to this practically unknown inventor. The significance of his epoch-making discoveries was quickly grasped and he was invited to deliver a lecture before the American Institute of Electrical Engineers on May 16, 1888. This invitation was evidence that he had "arrived." Tesla accepted the invitation and put his whole heart into preparing the lecture which, he felt, would enable him to tell the electrical world the magnificent story of his complete alternating-current system and the tremendous advantages it possessed over direct-current.

This lecture became a classic of the electrical engineering field. In it Tesla presented the theory and practical application of alternating-current to power engineering. This, with his patents, described the foundation, in the matter of circuits, machines and operation, and theory, upon which almost the entire electrical system of the country was established and is still operating today. No new development of anything even slightly approaching comparable magnitude has been made in the field of electrical engineering down to the present time.

Tesla's lecture, and the inventions and discoveries which he included in it, established him before the electrical engineering profession as the father of the whole field of alternating-current power system, and the outstanding inventor in the electrical field.

It is not easy to visualize the tremendous burst of electrical development and progress that came out of Tesla's laboratory in the few months after he established it. He produced a tidal wave of advancement which carried the electrical world into the opening of the new power age in one grand surge--although it took several years, naturally, for the commercial exploitation to get under way. The world of electrical engineering was amazed, bewildered and mystified by the host of discoveries thrown into its midst in rapid succession from the Tesla laboratory, and was filled with admiration for the prodigious new genius who had flared up within its ranks.

Tesla's power system, employing high voltage for transmission, released electrical powerhouses using direct current from functioning as purely local enterprises, capable of serving an area within a radius of one mile at the very most. His motors used alternating-current that could be economically transmitted hundreds of miles, and he provided an economical two- and three-phase system for transmission lines.

The stupendous changes which the Tesla alternating-current inventions and discoveries brought about in the electrical industry can be realized by considering the handicap under which the direct-current powerhouses of the Edison system had operated up to that time. Electricity was generated in powerhouses by relatively small-size dynamos, and the current then distributed to customers over copper conductors laid in conduits under the streets. Some of the electrical energy fed into these conductors at the powerhouse did not arrive as electricity at the far end of the line but was converted along the route to useless heat by the resistance of the conductors.

Electrical energy is composed of two factors, the current, or amount of electricity, and the voltage, or the pressure under which the current is moved. Resistance losses were undergone by the current regardless of the voltage. One ampere of current experienced a definite loss caused by resistance and this loss was the same whether the pressure was 100, or 1,000 or 100,000 volts. If the current value remained fixed, then the amount of energy transported over a wire varied with the voltage. There is, for example, 100,000 times as much energy transported over a wire carrying a current of one ampere at 100,000 volts as there is when the current is one ampere and the pressure is one volt.

If the amount of current carried by a wire is doubled, the heat losses are increased four fold; if the current is tripled, these losses are increased nine fold, and if the current is increased four fold, the losses rise sixteen fold. This situation put definite limits to the amount of current which could be loaded on to conductors.

In addition there is an accompanying drop in pressure. In a half-mile-long conductor, of the size adopted and under the average currents carried, there would be a drop of about 30 volts. To compensate for this, to some extent, the dynamos were designed to generate 120 volts instead of the standard 110 volts for which lamps were designed. Near the powerhouse the customers would get excess voltage--and a half-mile away their current would be delivered at 90 volts. The early Edison carbon lamps were none too brilliant at 110 volts and gave much less than satisfactory illumination at 90 volts.

As a result of this situation the generation and distribution of direct-electric current became very much of a localized matter. The Edison powerhouse could serve an area less than a mile in diameter. In order to give service to a large city it would be necessary to have a powerhouse in every square mile, or even closer if a uniformly satisfactory current were to be supplied. Outside large cities the situation became even more difficult. This was a severe handicap if electricity was to become the universal power source.

Tesla's alternating-current power system, which Edison so emphatically rejected when it was offered to him, freed electricity from its bondage to local isolation. Not alone were his alternating-current motors more simple and flexible than the direct-current machines, but it was possible by a highly efficient method of using transformers, which consisted of two coils of wire around an iron core, to step up the voltage and simultaneously step down the current in a proportionate amount, or use the process in reverse. The amount of energy involved, however, would remain practically unchanged.

Copper wire entails a heavy investment when it is bought by the mile. The diameter of the wire sets the limit to the amount of current it will carry. With the Edison direct-current system there was no practical way for transforming an electric current. The voltage remained fixed and when the current was increased to the carrying capacity of the wire no further expansion was possible on that circuit.

With the Tesla system the amount of energy a wire would transport would be increased tremendously by increasing the voltage and letting the current remain fixed below the carrying limit of the circuit. A very small wire could carry a thousand or more times as much electrical energy in the Tesla polyphase alternating system as it could in the Edison direct-current system.

By using Tesla's alternating-current system electricity could be delivered economically at vast distances from the powerhouse. It would be possible, if desired, to burn coal at the mouth of a mine for generating electricity, and deliver the current cheaply at distant cities, or to generate electricity where water power was available and transmit it to distant points where it could be used.

Tesla rescued the electrical giant from the apron strings of the powerhouse and gave it geographical freedom, the opportunity to expand into the wide-open spaces and work its magic. He laid the foundation for our present superpower system. A development of such magnitude was bound to be loaded with dynamite, and action was sure to follow as soon as someone set a match to the fuse.