Nikola Tesla, American scientist of Serbian origin, gave his greatest contribution to science and technological progress of the world as the inventor of the rotating magnetic field and of the complete system of production and distribution of electrical energy (motors, generators) based on the use of alternate currents. His name was given to the SI unit for magnetic induction (“tesla”). Tesla also constructed the generators of high-frequency alternate currents and high-voltage coreless transformer known today as “Tesla Coil”.

Nikola Tesla was born on July 10, 1856, at Smiljan, in the Military Border zone of Austro-Hungarian Empire, now in the Republic of Croatia. He received his education in Austria i.e. Austro-Hungary: primary school at Smiljan and Gospic (1862-70), and secondary school (Realgymnasium) at Karlovac (1870-1873). From 1875 to 1878 studied at the Polytechnic at Graz, and in 1880 he enrolled in the studies of natural philosophy at the Charles’ University in Prague.

In the period 1881-82 he was employed at the Central Telegraph Office in Budapest. Here he began his career as inventor improving the voice amplifier for the telephone receiver, and in February 1882 arrived on the idea of the rotating magnetic field.

In the middle of 1882 he travelled to Paris to join Edison’s Continental Company, and in 1883 moved to Strasbourg and made the prototype of the induction motor. In 1884 he travelled to USA to start working in Edison’s company. In 1885 he left Edison, founded his own “Tesla Arc & Light Co.” and started producing motors and generators for polyphase alternate currents.

The first patent, “Commutator for dynamo – electric machines”, applied to the Patent Office on May 6, 1885 was followed by a series of patents on electric arc lamp regulators. From 1887 to 1890 he applied his well-known patents on polyphase alternate currents, generators and motors. On May 16, 1888, he presented his inventions in his first lecture on “A new system of motors and transformers of alternate currents” to the American Institute of Electrical Engineers (AIEE). Immediately after that lecture, the Westinghouse Co. bought his 40 patents on polyphase currents. In Pittsburgh (1888-89), together with engineers of the Westinghouse Co., he was engaged on the practical realization of these patents. In this period the preparations for the construction of the first power plant at the Niagara Falls according to the Tesla’s system were made. The power plant was on January 12, 1895 put into operation and at that time it was reckoned as a wonder of the world.

Another wide field of his researches were alternate currents of high frequencies and their effects. On May 20, 1891, he gave a lecture to the AIEE in New York on the “Experiments with alternate currents of very high frequencies and their application in artificial lighting” In 1890 he also published the results of physiological effects of high-frequency currents.

From 1891 to 1896 Tesla applied patents on the spark oscillator coupled with a resonant transformer which substituted Hertz’s oscillator and Ruhmkorf’s inductor in his researches. In addition he also applied numerous patents for various auxiliary equipment e.g. circuit breakers, condensers etc.

In 1892, at the invitation of the Royal Society in London and French Physical Society he travelled to London and Paris to give the lecture on “Experiments with alternate currents of high potential and high frequency.” During his stay in Europe he also visited Belgrade on June 2, 1892.

In 1893, with his system of four circuits in resonance he showed that the aerial, connection with the ground and resonance were three essential elements of wireless telegraphy and prepared the way for the invention of modern radio.

In 1895 he continued his researches of high frequency currents and their effects on rarefied gases using Lenard tubes. He was one of the first scientist on the American continent who made X-ray photos of hands, sculls, knees and elbows. He was the first to point to the harmful effects of a long exposure to these rays on human organisms.

In 1897 he applied various patents from the area of wireless telegraphy, and in 1898 the patent of the method and apparatus for controlling mechanism of moving vessels or vehicles. In New York he performed the experiment with a remote-controlled boat. As a result of these patents, the Supreme Court if the USA granted him – though post-mortem – the priority in the invention of wireless telegraphy i.e. of radio.

From 1899 to 1900 Tesla stayed at Colorado Springs. At a height of 2000 m above sea level he built a laboratory with a 200 kW transmitter. He also constructed generators and transformers which produced frequencies of tens of thousands hertz and potentials up to 12 million volts, and improved his coreless transformer for high-frequency currents, known as Tesla transformer. In his notes on the experiments from this period he stated that the stationary waves spread through the Earth so that this effect could be used for wireless transmission of energy.

The patents from the area of wireless transmission of energy he applied from 1900 to 1902. From 1901 to 1905, intending to realize his “World-Wireless-System,” he was occupied with the construction of a great experimental station, a power plant and a great aerial tower on Long Island near New York. However, this project had never been completed.

Later (1909-1922), he was occupied with mechanical engineering, inventing new types of turbines, pumps, speed indicators, flow-meters etc. His pumps without paddles are nowadays being commercially used.

Tesla spent his last years in the hotel “New Yorker” in New York, where he died on January 7, 1943.

1856, 10 July
Born at Smiljan, a village near Gospić (a small town in Austrian-Empire, now in the Republic of Croatia);

3. Passed the final examination in the secondary school (Realgymnasium) at Karlovac;

   1875 – 1878.
   Studies at the Polytechnics in Graz;

   1880.
   Studies natural philosophy at the Charles’ University in Prague;

   1881.
   Starts working for the Central Telegraph Office in Budapest and makes his first invention: voice amplifier for the telephone receiver;

   1882.
   Invents the rotating magnetic field and leaves Budapest; finds employment in the Edison Continental Company in Paris

   1883.
   Spends six months working on the reconstruction of the power station in Strasbourg. Makes the first model of the induction motor;

   1884.
   Returns to Paris. On the recommendation of the Board in Paris travels to New York to work in the “Edison Machine Works”;

   1885.
   Leaves Edison’s company and founds the “Tesla Arc Light Co.” in New York. Makes first alternating current motors and generators. Applies his first patent “Commutator for Dynamo-electric Machines”, followed by patents on arc-lamps regulators;

   1887.
   Applies the patents on the polyphase alternating current motors and generators. Gives his first lecture: “New systems of Alternate Currents Motors and Transformers” before the AIEE (American Institute of Electrical Engineers); signs the contract with Westinghouse Electric Co. on the exploitation of his patents;

   1889.
   Works in the Westinghouse Electric Co. in Pittsburgh on the improvement of his motors. The production of these motors began in this year.

   1890.
   Begins the experiments with high-frequency currents. Invents the high-frequency current generator

4. Invents the coreless transformers.

   1892.
   Gives lectures in London and Paris on his latest researches (“”Experiments With Alternate Currents of high potential and high frequency”); visits his homeland and Belgrade.

   1893.
   Invents the wireless telegraphy system; achieves great success with his lectures at the World Exhibition in Chicago. Together with Westinghouse demonstrates his system of production, transmission and use of alternate currents, influencing decisively the acceptance of this project proposal for the construction of hydroelectric power plant at the Niagara Falls;

   1894 – 95.
   Invents mechanical oscillators and generators of electrical oscillations;

   1895.
   Fire destroys his laboratory in New York;

   1895-96.
   Makes experiments with X-rays;

   1897-98.
   Applies his first patents on the wireless transmissions of energy; demonstrates the model of the remote-controlled boat. (It was the first experiment of the use of radio waves for remote control)

   1899.
   Builds the laboratory at the Colorado Springs and performs experiments with the high-frequency transformer (Tesla Coil) of 12 million volts;

   1900 – 05.
   Constructs his Transmitting Tower i.e. the aerial for “World Telegraph” at Long Island, Wardencliff, N.Y.C., intending to create the world-wide system for the transmission of information and energy;

   1907.
   Makes the first model of the turbine based on a new principle of the utilization of the energy of the fluid by the viscous friction.

   1908.
   The model of the new pump was tested in a factory of an American-British company;

   1909.
   Makes drafts and plans for aeromobile; makes first tests with the steam and gas turbines

   1911-13.
   Tests his steam turbines in the Edison’s power plant in New York

   1913.
   Obtains patents for the pump and turbine based on a new principle. Co-operates with the Dressel Co. on the project of a generator for the front light of a locomotive engine;

   1914.
   Applies patents on several types of speed indicators; constructs new types of fountains etc.;

   1917.
   Works on the project of a turbo-generator

   1918.- 20.
   Co-operates with the Alis Chalmers Co. on the production and testing of his steam and gas turbines

   1920-23.
   Co-operates with the Bud Co. on the production of automobile motors;

   1928.
   Applies patents for the vertically ascending aeroplane;

   1930 – 35.
   Studies the possibilities of the improvements in the production and processing of sulphur, iron and copper;

   1936.
   Makes project proposals for telegeodynamics or the energy transmission through the earth and of defensive weapon known as “death rays”

   1937.
   Injured in the traffic accident in New York

   1943, 7 Jan.
   Died in the hotel “New Yorker” in New York.

Question:Which of his inventions Tesla considered to be his best?

Answer: In his autobiography “My Inventions,” Tesla mentions the invention of the high-voltage transmitter as his “best invention”. The high-voltage transmitter is a converter producing voltages of several million volts.
It was adjusted to induce the Earth, which Tesla considered to be an excellant conductor, through which the energy could be transmitted to any point on the planet.

Q:Did Tesla receive the Nobel Prize?

A: Tesla never received the Nobel Prize. In 1915, on November 5, the correspondents of Daily Telegraph and the Telegraph Agency from Copenhagen wired the news that Nikola Tesla and Thomas Edison should receive the Nobel Prize for physics. This news provoked a great interest of the public, but the news proved to be false. Tesla and Edison were not officially nominated for the Nobel Prize that year. In 1937, Professor Felix Erenhaft from Vienna submitted a proposal to the Nobel Prize Committee with the explication for the nomination of Nikola Tesla for the prize in physics, for the discovery of high-frequency currents and the rotating magnetic field. The proposal was rejected on the grounds that Tesla’s inventions, however brilliant and significant in a broad field of electro engineering, were realized forty years ago, and that the Nobel Committee is not awarding prizes for contributions realized in the past.

Q: What are Tesla’s Currents?

A: In 1891, Tesla discovered the device that will become known as Tesla’s Oscillator of High-Frequency Currents. The apparatus of Tesla’s Oscillator consists of a high-frequency transformer without an iron core, and a sparker.

The currents produced by Tesla’s Oscillators have frequencies of several tens of thousands Hz, and are scientifically called Tesla’s Currents.

The material for the Museum arrived in Belgrade according to the decision of the American court, which declared Mr. Sava Kosanovic, Tesla’s nephew, for the only rightful heir. In 1951, in accordance with Tesla’s last wish, Mr. Kosanovic transferred all the documents and Tesla’s personal things in Belgrade.

Nikola Tesla Museum is a unique institution of science and culture in Serbia and in the world. It is the only museum in the world which preserves the original and personal inheritance of Nikola Tesla. It possesses several exceptionally valuable collections:

above 160 000 original documents,
above 2000 books and journals,
above 1200 historical technical exhibits,
above 1500 photographs and photo plates of original, technical objects, instruments and apparatus,
above 1000 plans and drawings.

As the institution which preserves the most abundant in the world collection of documents on life and work of Nikola Tesla, the Museum plays a significant role in providing abundant information to the researchers of history of science, inventions and patent rights as well as for environmental protection projects and studies of pollution-free energy sources.

A particular role of the Museum is the organization, support and promotion of the investigations from the history of science, which could possibly afford a better recognition of Tesla’s contribution to the development of science and engineering at the end of the 19th and the beginning of the 20th century.