Nikola Tesla Articles
had the knowledge ("Jour. Soc. Tel. Eng." and "Electricity," Vol. 13, p. 496 and p. 515; "Electrician," November 15, 1884, p. 11; "Electric Illumination," by Dredge, London, 1882, Vol. 1, p. 69; "L'Electricien," August 1, 1884, p. 131; United States patent, No. 390,439) years before Tesla and Ferraris published the rotating field principle in 1888.
The synchronous motor, however, finds its applications in conditions of large power and continuous running. Those conditions are furnished by the great long-distance systems of power transmission of to-day, and it is only in such systems that the synchronous motor is or ever has been used. No such systems existed in 1888, and it was for this reason that though the reversibility of the alternating-current generator was known, it had never been utilized. The machine was there, but the conditions for its use were lacking. What was wanted then, and is wanted now, for general distribution and subdivision of power, was a small self-starting motor. This requirement is met by the "rotary field" or "induction" motor of to-day.
The man, in my opinion, to whom the induction motor is chiefly due is Dobrowolski. He was the first clearly to perceive the theory of its operation and the requirements in its design. To produce the maximum action of the alternating currents on the other member he perceived the necessity of a minimum magnetic air gap He gained the desired result, among other things, by imbedding the conductors in the iron, and his motor was a success. The first commercially successful induction motor of any size was the one built by him and exhibited at Frankfort in 1891. His designs were successfully copied in this country, and the induction motor of to-day became a fact.
After Tesla's apparent failure in motor production he turned to more promising fields. In 1891 he burst upon the electrical world with the first of a series of the most remarkable lectures ever delivered before a scientific audience. The experiments shown were fairly startling. Lamps and motors were operated on open circuit with a single-line wire. Lamps were made to burn brightly when short-circuited by a heavy copper bar, while exhausted tubes were brought to incandescence without any wire near them. Tubes were lighted by merely approaching them with the hand. Beautiful flames of varied appearance were made to leap from many objects, even from the hand of the lecturer himself.
Before the eyes of the startled spectators Tesla touched both terminals of a 200,000-volt transformer, with no more serious result than the production of the flames aforesaid. And throughout the lecture vague hints were offered of the tremendous possibilities exposed by the experiments possibilities of obtaining unlimited light and power anywhere on the earth's surface, not by means of expensive wires from costly central stations, but by taking the energy directly from the earth itself or from the circumambient ether.
The public was astounded. Popular opinion, ever ready to ascribe the most impossible attributes to that vaguely understood force, electricity, hailed the lectures as disclosing a new era of wonders and Tesla as the last and greatest of electrical wizards. Even the eye of science was dazzled by Tesla's brilliant flames, and the most extravagant tributes were poured upon him. As stated in the London "Electrical Engineer": "No man in our age has achieved such a universal scientific reputation in a sin- gle stride as this gifted young electrical engineer."
