Editing Nikola Tesla (section)

== New York laboratories ==
[[File:Twain in Tesla's Lab.jpg|thumb|alt=Mark Twain in Tesla's lab, 1894|[[Mark Twain]] in Tesla's South Fifth Avenue laboratory, 1894]]

The money Tesla made from licensing his AC patents made him [[independently wealthy]] and gave him the time and funds to pursue his own interests.<ref>{{cite journal | url = https://teslauniverse.com/nikola-tesla/articles/nikola-tesla-scientific-savant | title = Nikola Tesla: Scientific Savant from the Tesla Universe Article Collection | first = James P. |last = Rybak | journal = [[Popular Electronics]] | date = November 1999 | pages = 40–48 & 88 | access-date = 21 January 2017 | archive-date = 26 February 2019 | archive-url = https://web.archive.org/web/20190226121548/https://teslauniverse.com/nikola-tesla/articles/nikola-tesla-scientific-savant | url-status = live }}</ref> In 1889, Tesla moved out of the Liberty Street shop Peck and Brown had rented and for the next dozen years worked out of a series of workshop/laboratory spaces in [[Manhattan]]. These included a lab at 175 [[Grand Street (Manhattan)|Grand Street]] (1889–1892), the fourth floor of 33–35 South [[Fifth Avenue]] (1892–1895), and sixth and seventh floors of 46 & 48 East [[Houston Street]] (1895–1902).<ref>Carlson, W. Bernard (2013). ''Tesla: Inventor of the Electrical Age'', Princeton University Press, p. 218</ref><ref>{{cite web|url=https://teslaresearch.jimdo.com/labs-in-new-york-1889-1902/|title=Laboratories in New York (1889–1902)|website=Open Tesla Research|access-date=21 January 2017|archive-date=20 August 2018|archive-url=https://web.archive.org/web/20180820234947/https://teslaresearch.jimdo.com/labs-in-new-york-1889-1902/|url-status=live}}</ref> Tesla and his hired staff conducted some of his most significant work in these workshops.

=== Tesla coil ===
{{Main|Tesla coil}}

In the summer of 1889, Tesla traveled to the [[Exposition Universelle (1889)|1889 Exposition Universelle]] in Paris and learned of [[Heinrich Hertz]]'s 1886–1888 experiments that proved the existence of [[electromagnetic radiation]], including [[radio wave]]s.{{sfn|Carlson|2013|p=120}} In repeating and then expanding on these experiments Tesla tried powering a [[Induction coil|Ruhmkorff coil]] with a high speed [[alternator]] he had been developing as part of an improved [[Arc lamp|arc lighting]] system but found that the high-frequency current overheated the iron core and melted the insulation between the primary and secondary windings in the coil. To fix this problem Tesla came up with his "oscillating transformer", with an air gap instead of insulating material between the primary and secondary windings and an iron core that could be moved to different positions in or out of the coil.{{sfn|Carlson|2013|p=122}} Later called the Tesla coil, it would be used to produce high-[[voltage]], low-[[Electric current|current]], high [[frequency]] [[alternating current|alternating-current]] electricity.<ref name="NMFL">{{cite web |title=Tesla coil |work=Museum of Electricity and Magnetism, Center for Learning |publisher=National High Magnetic Field Laboratory website, Florida State Univ. |date=2011 |url=https://nationalmaglab.org/education/magnet-academy/history-of-electricity-magnetism/museum/tesla-coil-1891 |access-date=12 September 2013 |archive-date=23 September 2015 |archive-url=https://web.archive.org/web/20150923174243/https://nationalmaglab.org/education/magnet-academy/history-of-electricity-magnetism/museum/tesla-coil-1891 |url-status=live }}</ref> He would use this [[resonant transformer|resonant transformer circuit]] in his later wireless power work.{{sfn|Carlson|2013|p=124}}<ref name="BurnettOperation">{{cite web
  | last = Burnett
  | first = Richie
  | title = Operation of the Tesla Coil
  | work = Richie's Tesla Coil Web Page
  | publisher = Richard Burnett private website
  | date = 2008
  | url = http://www.richieburnett.co.uk/operation.html#operation
  | access-date = 24 July 2015
| archive-date = 20 July 2015
| archive-url = https://web.archive.org/web/20150720104724/http://www.richieburnett.co.uk/operation.html#operation
  | url-status = live
  }}</ref>

=== Citizenship ===
On 30 July 1891, aged 35, Tesla became a [[naturalized citizen]] of the United States.<ref name="NYcourts">{{Cite web |url=https://www.fold3.com/image/20564444?ann=f3dc7880-a283-11dc-2973-11792d3d4a08 |title=Naturalization Record of Nikola Tesla, 30 July 1891 |access-date=24 October 2021 |archive-date=24 October 2021 |archive-url=https://web.archive.org/web/20211024010806/https://www.fold3.com/image/20564444?ann=f3dc7880-a283-11dc-2973-11792d3d4a08 |url-status=live }}, Naturalization Index, NYC Courts, referenced in Carlson (2013), ''Tesla: Inventor of the Electrical Age'', p. H-41</ref>{{sfn|Carlson|2013|p=138}} In the same year, he patented his Tesla coil.<ref name="Uth">{{cite web|last=Uth|first=Robert|title=Tesla coil|date=12 December 2000|work=Tesla: Master of Lightning|publisher=PBS.org|url=https://www.pbs.org/tesla/ins/lab_tescoil.html|access-date=20 May 2008|archive-date=5 September 2019|archive-url=https://web.archive.org/web/20190905184548/http://www.pbs.org/tesla/ins/lab_tescoil.html|url-status=live}}</ref>

=== Wireless lighting ===

[[File:TeslaWirelessPower1891.png|thumb|right|Tesla demonstrating wireless lighting by "electrostatic induction" during an 1891 lecture at [[Columbia College (New York)|Columbia College]] via two long [[Geissler tube]]s (similar to [[Neon light|neon tubes]]) in his hands]]

After 1890, Tesla experimented with transmitting power by inductive and capacitive coupling using high AC voltages generated with his Tesla coil.<ref name="Tesla1891">{{Cite book |url=http://www.tfcbooks.com/tesla/1891-05-20.htm |title=Experiments with Alternate Currents of Very High Frequency and Their Application to Methods of Artificial Illumination |first=Nikola |last=Tesla |publication-date=20 May 1891 |access-date=21 January 2017 |archive-date=6 March 2023 |archive-url=https://web.archive.org/web/20230306023235/http://www.tfcbooks.com/tesla/1891-05-20.htm |url-status=live }}, lecture delivered before the [[American Institute of Electrical Engineers]], Columbia College, New York. Reprinted as a {{cite book |title = book of the same name by |publisher = Wildside Press |date = 2006 |url = https://books.google.com/books?id=94eH3rULPy4C |isbn = 0-8095-0162-7 |access-date = 21 January 2017 |archive-date = 23 March 2024 |archive-url = https://web.archive.org/web/20240323123047/https://books.google.com/books?id=94eH3rULPy4C |url-status = live }}</ref> He attempted to develop a wireless lighting system based on [[Near and far field|near-field]] inductive and capacitive coupling and conducted a series of public demonstrations where he lit [[Geissler tube]]s and even incandescent light bulbs from across a stage.{{sfn|Carlson|2013|p=132}} He spent most of the decade working on variations of this new form of lighting with the help of various investors but none of the ventures succeeded in making a commercial product out of his findings.<ref>Christopher Cooper (2015). ''The Truth About Tesla: The Myth of the Lone Genius in the History of Innovation'', Race Point Publishing, pp. 143–144</ref>

In 1893 at [[St. Louis]], Missouri, the [[Franklin Institute]] in [[Philadelphia]], Pennsylvania and the [[National Electric Light Association]], Tesla told onlookers that he was sure a system like his could eventually conduct "intelligible signals or perhaps even power to any distance without the use of wires" by conducting it through the Earth.{{sfn|Carlson|2013|pp=178–179}}<ref name="Orton">{{cite book |last=Orton |first=John |title=The Story of Semiconductors |year=2004 |publisher=Oxford University Press |location=Oxford, England |page=53}}</ref>

Tesla served as a vice-president of the [[American Institute of Electrical Engineers]] from 1892 to 1894, the forerunner of the modern-day [[IEEE]] (along with the [[Institute of Radio Engineers]]).<ref>{{cite web|title=Tesla's Connection to Columbia University|url=http://www.teslasociety.com/columbia.pdf|publisher=Tesla Memorial Society of NY|access-date=5 July 2012|first1=Kenneth L.|last1=Corum|first2=James F.|last2=Corum|name-list-style=amp|archive-date=18 November 2017|archive-url=https://web.archive.org/web/20171118002803/http://www.teslasociety.com/columbia.pdf|url-status=live}}</ref>

=== {{anchor|The "Tesla Polyphase System"}}Polyphase system and the Columbian Exposition ===
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[[File:TeslaPOLYPHASEColumbianEXPO1893rwLIPACKownerA.pdf|thumbnail|A Westinghouse display of the "Tesla Polyphase System" at Chicago's 1893 Columbian Exposition]]

By the beginning of 1893, Westinghouse engineer [[Charles F. Scott (engineer)|Charles F. Scott]] and then [[Benjamin G. Lamme]] had made progress on an efficient version of Tesla's induction motor. Lamme found a way to make the [[polyphase system]] it would need compatible with older single-phase AC and DC systems by developing a [[rotary converter]].{{sfn|Carlson|2013|p=166}} Westinghouse Electric now had a way to provide electricity to all potential customers and started branding their polyphase AC system as the "Tesla Polyphase System". They believed that Tesla's patents gave them [[Priority right|patent priority]] over other polyphase AC systems.{{sfn|Carlson|2013|p=167}}

Westinghouse Electric asked Tesla to participate in the 1893 [[World's Columbian Exposition]] in Chicago where the company had a large space in the "Electricity Building" devoted to electrical exhibits. Westinghouse Electric won the bid to light the Exposition with alternating current and it was a key event in the history of AC power, as the company demonstrated to the American public the safety, reliability, and efficiency of an alternating current system that was polyphase and could also supply the other AC and DC exhibits at the fair.<ref>{{cite book |first=Richard |last=Moran |title=Executioner's Current: Thomas Edison, George Westinghouse, and the Invention of the Electric Chair |publisher=Knopf Doubleday Publishing Group |date=2007 |page=222}}</ref><ref>{{cite book |url=https://books.google.com/books?id=-ErxIGp3QN0C |title=America at the Fair: Chicago's 1893 World's Columbian Exposition |first=Chaim M. |last=Rosenberg |publisher=Arcadia Publishing |date=20 February 2008 |isbn=978-0-7385-2521-1 |access-date=3 November 2021 |archive-date=23 March 2024 |archive-url=https://web.archive.org/web/20240323123130/https://books.google.com/books?id=-ErxIGp3QN0C |url-status=live }}</ref><ref>{{cite book|url=https://books.google.com/books?id=F6cWRxU9go4C&pg=PR21|title=The World's Columbian Exposition: A Centennial Bibliographic Guide|first1=David J.|last1=Bertuca|first2=Donald K.|last2=Hartman|first3=Susan M.|last3=Neumeister|year=1996|name-list-style=amp|pages=xxi|publisher=Bloomsbury Academic|isbn=978-0-313-26644-7|access-date=10 September 2012|archive-date=23 March 2024|archive-url=https://web.archive.org/web/20240323123640/https://books.google.com/books?id=F6cWRxU9go4C&pg=PR21|url-status=live}}</ref>

A special exhibit space was set up to display various forms and models of Tesla's induction motor. The rotating magnetic field that drove them was explained through a series of demonstrations including an ''[[Tesla's Egg of Columbus|Egg of Columbus]]'' that used the two-phase coil found in an induction motor to spin a copper egg making it stand on end.<ref>Hugo Gernsback, "Tesla's Egg of Columbus, How Tesla Performed the Feat of Columbus Without Cracking the Egg" Electrical Experimenter, 19 March 1919, p. 774 [http://www.teslacollection.com/tesla_articles/1919/electrical_experimenter/h_gernsback/the_tesla_egg_of_columbus] {{Webarchive|url=https://web.archive.org/web/20200327222415/http://www.teslacollection.com/tesla_articles/1919/electrical_experimenter/h_gernsback/the_tesla_egg_of_columbus|date=27 March 2020}}</ref>

Tesla visited the fair for a week during its six-month run to attend the [[International Electrical Congress]] and put on a series of demonstrations at the Westinghouse exhibit.{{sfn|Seifer|2001|p=120}}<ref>Thomas Commerford Martin, The Inventions, Researches and Writings of Nikola Tesla: With Special Reference to His Work in Polyphase Currents and High Potential Lighting, Electrical Engineer – 1894, Chapter XLII, page 485 [https://archive.org/details/inventionsresear00martiala]</ref> A specially darkened room had been set up where Tesla showed his wireless lighting system, using a demonstration he had previously performed throughout America and Europe;{{sfn|Cheney|2001|p=76}} these included using high-voltage, high-frequency alternating current to light wireless [[gas-discharge lamp]]s.{{sfn|Cheney|2001|p=79}}

An observer noted:

{{blockquote|Within the room were suspended two hard-rubber plates covered with tin foil. These were about fifteen feet apart and served as terminals of the wires leading from the transformers. When the current was turned on, the lamps or tubes, which had no wires connected to them, but lay on a table between the suspended plates, or which might be held in the hand in almost any part of the room, were made luminous. These were the same experiments and the same apparatus shown by Tesla in London about two years previous, "where they produced so much wonder and astonishment".<ref>{{cite book |title=Electricity at the Columbian Exposition; Including an Account of the Exhibits in the Electricity Building, the Power Plant in Machinery Hall |publisher=R. R. Donnelley |last=Barrett |first=John Patrick |year=1894 |pages=[https://archive.org/details/electricityatco00barrgoog/page/n288 268]–269 |url=https://archive.org/details/electricityatco00barrgoog |access-date=29 November 2010}}</ref>}}

=== Steam-powered oscillating generator ===
{{Main|Tesla's oscillator}}

During his presentation at the International Electrical Congress in the Columbian Exposition Agriculture Hall, Tesla introduced his [[Tesla's oscillator|steam-powered reciprocating electricity generator]] that he patented that year, something he thought was a better way to generate alternating current.{{sfn|Carlson|2013|p=182}} Steam was forced into the oscillator and rushed out through a series of ports, pushing a piston up and down that was attached to an armature. The magnetic armature vibrated up and down at high speed, producing an alternating [[magnetic field]]. This [[electromagnetic induction|induced]] alternating electric current in the wire coils located adjacent. It did away with the complicated parts of a steam engine/generator, but never caught on as a feasible engineering solution to generate electricity.{{sfn|Carlson|2013|pp=181–185}}<ref>Reciprocating Engine, {{US patent|514169}}, 6 February 1894.</ref>

=== Consulting on Niagara ===

In 1893, [[Edward Dean Adams]], who headed the [[Niagara Falls]] [[Cataract Construction Company]], sought Tesla's opinion on what system would be best to transmit power generated at the falls. Over several years, there had been a series of proposals and open competitions on how best to do it. Among the systems proposed by several US and European companies were two-phase and three-phase AC, high-voltage DC, and compressed air. Adams asked Tesla for information about the current state of all the competing systems. Tesla advised Adams that a two-phased system would be the most reliable and that there was a Westinghouse system to light incandescent bulbs using two-phase alternating current. The company awarded a contract to Westinghouse Electric for building a two-phase AC generating system at the Niagara Falls, based on Tesla's advice and Westinghouse's demonstration at the Columbian Exposition. At the same time, a further contract was awarded to General Electric to build the AC distribution system.{{sfn|Carlson|2013|pp=167–173}}

=== The Nikola Tesla Company ===
In 1895, Edward Dean Adams, impressed with what he saw when he toured Tesla's lab, agreed to help found the Nikola Tesla Company, set up to fund, develop, and market a variety of previous Tesla patents and inventions as well as new ones. Alfred Brown signed on, bringing along patents developed under Peck and Brown. The board was filled out with William Birch Rankine and Charles F. Coaney.{{sfn|Carlson|2013|pp=205–206}} It found few investors, since the mid-1890s were a tough time financially, and the wireless lighting and oscillators patents it was set up to market never panned out. The company handled Tesla's patents for decades to come.

=== Lab fire ===

In the early morning hours of 13 March 1895, the South Fifth Avenue building that housed Tesla's lab caught fire. It started in the basement of the building and was so intense Tesla's 4th-floor lab burned and collapsed into the second floor. The fire not only set back Tesla's ongoing projects, but it also destroyed a collection of early notes and research material, models, and demonstration pieces, including many that had been exhibited at the 1893 Worlds Colombian Exposition. Tesla told ''[[The New York Times]]'' "I am in too much grief to talk. What can I say?".<ref>Mr. Tesla's Great Loss, All of the Electrician’s Valuable Instruments Burned, WORK OF HALF A LIFETIME GONE, New York Times, 14 March 1895 (archived at [https://teslauniverse.com/nikola-tesla/articles/mr-teslas-great-loss teslauniverse.com] {{Webarchive|url=https://web.archive.org/web/20220628160738/https://teslauniverse.com/nikola-tesla/articles/mr-teslas-great-loss |date=28 June 2022 }})</ref>  After the fire Tesla moved to 46 & 48 East Houston Street and rebuilt his lab on the 6th and 7th floors.

=== X-ray experimentation ===
[[File:X-Ray Photograph of Tesla's left hand.jpg|left|thumb|X-ray Tesla took of his hand]]

Starting in 1894, Tesla began investigating what he referred to as [[radiant energy]] of "invisible" kinds after he had noticed damaged film in his laboratory in previous experiments<ref>{{cite book|last1=Tesla|first1=Nikola|title=X-ray vision: Nikola Tesla on Roentgen rays|date=2007|publisher=Wiilder Publications|location=Radford, VA|isbn=978-1-934451-92-2|edition=1st}}</ref> (later identified as "Roentgen rays" or "[[X-rays]]"). His early experiments were with [[Crookes tube]]s, a [[cold cathode]] electrical discharge tube. Tesla may have inadvertently captured an X-ray image—predating, by a few weeks, [[Wilhelm Röntgen]]'s December 1895 announcement of the discovery of X-rays—when he tried to photograph Mark Twain illuminated by a [[Geissler tube]], an earlier type of gas discharge tube. The only thing captured in the image was the metal locking screw on the camera lens.{{sfn|Cheney|2001|p=134}}

In March 1896, after hearing of Röntgen's discovery of X-ray and X-ray imaging ([[radiography]]),<ref>RADIOGRAPHY – EXPERIMENTS MADE BY NIKOLA TESLA – Shoulder of a Man Taken Through His Clothing—Chalky Deposits Infallibly Detected, The Constitution, Atlanta, Georgia, Friday 13, March 1896,  p. 9 [http://anengineersaspect.blogspot.com/2011/07/nikola-tesla-radiography-experiments.html online archive] {{Webarchive|url=https://web.archive.org/web/20131004213023/http://anengineersaspect.blogspot.com/2011/07/nikola-tesla-radiography-experiments.html |date=4 October 2013 }}</ref> Tesla proceeded to do his own experiments in X-ray imaging, developing a high-energy single-terminal [[vacuum tube]] of his own design that had no target electrode and that worked from the output of the Tesla coil (the modern term for the phenomenon produced by this device is ''[[bremsstrahlung]]'' or ''braking radiation''). In his research, Tesla devised several experimental setups to produce X-rays. Tesla held that, with his circuits, the "instrument will&nbsp;... enable one to generate Roentgen rays of much greater power than obtainable with ordinary apparatus".<ref>{{cite book |first=Nikola |last=Tesla |url=http://www.tfcbooks.com/tesla/1898-11-17.htm |chapter=High Frequency Oscillators for Electro-Therapeutic and Other Purposes |title=Proceedings of the American Electro-Therapeutic Association |publisher=American Electro-Therapeutic Association |page=25 |date=17 November 1898 |access-date=27 January 2009 |archive-date=1 January 2016 |archive-url=https://web.archive.org/web/20160101011808/http://www.tfcbooks.com/tesla/1898-11-17.htm |url-status=live }}</ref>

Tesla noted the hazards of working with his circuit and single-node X-ray-producing devices. In his many notes on the early investigation of this phenomenon, he attributed the skin damage to various causes. He believed early on that damage to the skin was not caused by the Roentgen rays, but by the [[ozone]] generated in contact with the skin, and to a lesser extent, by [[nitrous acid]]. Tesla incorrectly believed that X-rays were longitudinal waves, such as those produced in [[waves in plasmas]]. These plasma waves can occur in [[force-free magnetic field]]s.<ref>Griffiths, David J. ''Introduction to Electrodynamics'', {{ISBN|0-13-805326-X}} and Jackson, John D. ''Classical Electrodynamics'', {{ISBN|0-471-30932-X}}.</ref><ref>{{cite book |title=Transactions of the American Electro-therapeutic Association |publisher=American Electrotherapeutic Association |year=1899 |page=16 |url=https://books.google.com/books?id=bUo7vYNkbKQC |access-date=25 November 2010 |archive-date=23 March 2024 |archive-url=https://web.archive.org/web/20240323123806/https://books.google.com/books?id=bUo7vYNkbKQC |url-status=live }}</ref>

On 11 July 1934, the ''[[New York Herald Tribune]]'' published an article on Tesla, in which he recalled an event that occasionally took place while experimenting with his single-electrode vacuum tubes. A minute particle would break off the cathode, pass out of the tube, and physically strike him:<ref name=Anderson>{{cite book |last=Anderson |first=Leland |title=Nikola Tesla's teleforce & telegeodynamics proposals |year=1998 |publisher=21st Century Books |location=Breckenridge, Colo. |isbn=0-9636012-8-8}}</ref>
<blockquote>
Tesla said he could feel a sharp stinging pain where it entered his body, and again at the place where it passed out. In comparing these particles with the bits of metal projected by his "electric gun", Tesla said, "The particles in the beam of force&nbsp;... will travel much faster than such particles&nbsp;... and they will travel in concentrations".
</blockquote>

=== Radio remote control ===

[[File:Tesla boat1.jpg|thumb|upright|In 1898, Tesla demonstrated a radio-controlled boat, which he hoped to sell as a guided torpedo to navies around the world.<ref>W. Bernard Carlson, Tesla: Inventor of the Electrical Age, Princeton University Press – 2013, p.&nbsp;231.</ref>]]

In 1898, Tesla demonstrated a boat that used a [[coherer]]-based [[radio control]]—which he dubbed "telautomaton"—to the public during an electrical exhibition at [[Madison Square Garden (1890)|Madison Square Garden]].{{sfn|Jonnes|2004}} Tesla tried to sell his idea to the US military as a type of radio-controlled [[torpedo]], but they showed little interest.<ref>{{cite book |url=https://books.google.com/books?id=6aStP3Du5cgC&pg=PT50 |first=P. W. |last=Singer |title=Wired for War: The Robotics Revolution and Conflict in the Twenty-first Century |date=2009 |publisher=Penguin |isbn=978-1-4406-8597-2 |via=Google Books |access-date=10 September 2012 |archive-date=23 March 2024 |archive-url=https://web.archive.org/web/20240323123553/https://books.google.com/books?id=6aStP3Du5cgC&pg=PT50#v=onepage&q&f=false |url-status=live }}</ref> Remote [[radio control]] remained a novelty until World War I and afterward, when a number of countries used it in [[glide bomb|military programs]].<ref>Fitzsimons, Bernard, ed. "Fritz-X", in ''The Illustrated Encyclopedia of 20th Century Weapons and Warfare'' (London: Phoebus, 1978), Volume 10, p.1037.</ref> Tesla took the opportunity to further demonstrate "Teleautomatics" in an address to a meeting of the Commercial Club in Chicago, while he was traveling to [[Colorado Springs, Colorado|Colorado Springs]], on 13 May 1899.