Editing Nikola Tesla (section)

== Later years ==

After Wardenclyffe closed, Tesla continued to write to Morgan; after "the great man" died, Tesla wrote to Morgan's son Jack, trying to get further funding for the project. In 1906, Tesla opened offices at 165 Broadway in Manhattan, trying to raise further funds by developing and marketing his patents. He went on to have offices at the [[Metropolitan Life Insurance Company Tower|Metropolitan Life Tower]] from 1910 to 1914; rented for a few months at the [[Woolworth Building]], moving out because he could not afford the rent; and then to office space at 8 West 40th Street from 1915 to 1925. After moving to 8 West 40th Street, he was effectively bankrupt. Most of his patents had run out and he was having trouble with the new inventions he was trying to develop.{{sfn|Carlson|2013|pp=373–375}}

=== Bladeless turbine ===
{{Main|Tesla turbine}}
[[File:TeslaTurbineOriginal.png|thumb|Tesla's bladeless turbine design]]

On his 50th birthday, in 1906, Tesla demonstrated a {{convert|200|hp|kW|abbr=off}} 16,000&nbsp;rpm [[Tesla turbine|bladeless turbine]]. During 1910–1911, at the [[Waterside Generating Station|Waterside Power Station]] in New York, several of his bladeless turbine engines were tested at 100–5,000&nbsp;hp.{{sfn|Carlson|2013|p=371}} Tesla worked with several companies including from 1919 to 1922 in [[Milwaukee]], for [[Allis-Chalmers]].{{sfn|Seifer|2001|p=398}}{{sfn|Carlson|2013|p=373}} He spent most of his time trying to perfect the Tesla turbine with Hans Dahlstrand, the head engineer at the company, but engineering difficulties meant it was never made into a practical device.{{sfn|O'Neill|1944}}{{page needed|date=May 2024}} Tesla did license the idea to a precision instrument company and it found use in the form of luxury car [[speedometer]]s and other instruments.{{sfn|Cheney|Uth|Glenn|1999|p=115}}

=== Wireless lawsuits ===

When [[World War I]] broke out, the British cut the transatlantic telegraph cable linking the US to [[German Empire|Germany]] in order to control the flow of information between the two countries. They also tried to shut off German wireless communication to and from the US by having the US Marconi Company sue the German radio company [[Telefunken]] for patent infringement.{{sfn|Carlson|2013|p=377}} Telefunken brought in the physicists [[Jonathan Zenneck]] and [[Karl Ferdinand Braun]] for their defense, and hired Tesla as a witness for two years for $1,000 a month. The case stalled and then went moot when the US entered the war against Germany in 1917.{{sfn|Carlson|2013|p=377}}{{sfn|Seifer|2001|p=373}}

In 1915, Tesla attempted to sue the [[Marconi Company]] for infringement of his wireless tuning patents. Marconi's initial radio patent had been awarded in the US in 1897, but his 1900 patent submission covering improvements to radio transmission had been rejected several times, before it was finally approved in 1904, on the grounds that it infringed on other existing patents including two 1897 Tesla wireless power tuning patents.<ref name="earlyradiohistory.us" /><ref>Howard B. Rockman, Intellectual Property Law for Engineers and Scientists, John Wiley & Sons – 2004, p. 198.</ref><ref>{{Cite web|url=https://supreme.justia.com/cases/federal/us/320/1/|title=Marconi Wireless Tel. Co. v. United States, 320 U.S. 1 (1943)|website=Justia Law|access-date=29 January 2017|archive-date=25 June 2017|archive-url=https://web.archive.org/web/20170625130248/https://supreme.justia.com/cases/federal/us/320/1/|url-status=live}}</ref> Tesla's 1915 case went nowhere,{{sfn|Carlson|2013|p=377-378}} but in a related case, where the Marconi Company tried to sue the US government over WWI patent infringements, a [[Supreme Court of the United States]] 1943 decision restored the prior patents of [[Oliver Lodge]], [[John Stone Stone|John Stone]], and Tesla.<ref name="LQsxMxEUC page 3">{{cite book |url=https://books.google.com/books?id=c92LQsxMxEUC&q=British+Court+tesla+radio&pg=PA3 |title=Jean-Michel Redouté, Michiel Steyaert, EMC of Analog Integrated Circuits |page=3 |access-date=18 March 2013 |isbn=978-90-481-3230-0 |last1=Redouté |first1=Jean-Michel |last2=Steyaert |first2=Michiel |date=10 October 2009 |publisher=Springer |archive-date=23 March 2024 |archive-url=https://web.archive.org/web/20240323123811/https://books.google.com/books?id=c92LQsxMxEUC&q=British+Court+tesla+radio&pg=PA3#v=snippet&q=British%20Court%20tesla%20radio&f=false |url-status=live }}</ref> The court declared that their decision had no bearing on Marconi's claim as the first to achieve radio transmission, just that since Marconi's claim to certain patented improvements were questionable, the company could not claim infringement on those same patents.<ref name="earlyradiohistory.us" /><ref>{{cite book |url=https://books.google.com/books?id=SdGaiV6iup0C&q=supreme+court+1943+radio+marconi&pg=PA3 |title=Robert Sobot, Wireless Communication Electronics:Introduction to RF Circuits and Design Techniques |page=4 |date=18 February 2012 |access-date=18 March 2013 |isbn=978-1-4614-1116-1 |last1=Sobot |first1=Robert |publisher=Springer |archive-date=23 March 2024 |archive-url=https://web.archive.org/web/20240323123556/https://books.google.com/books?id=SdGaiV6iup0C&q=supreme+court+1943+radio+marconi&pg=PA3#v=snippet&q=supreme%20court%201943%20radio%20marconi&f=false |url-status=live }}</ref>

=== Nobel Prize rumors ===

On 6 November 1915, a [[Reuters]] news agency report from London had the 1915 [[Nobel Prize in Physics]] awarded to Thomas Edison and Nikola Tesla; however, on 15 November, a Reuters story from Stockholm stated the prize that year was being awarded to [[William Henry Bragg]] and [[Lawrence Bragg]] "for their services in the analysis of crystal structure by means of X-rays".{{sfn|Cheney|2001|p=245}}<ref>{{cite web |title=The Nobel Prize in Physics 1915 |url=https://www.nobelprize.org/nobel_prizes/physics/laureates/1915/ |publisher=nobelprize.org |access-date=29 July 2012 |archive-date=8 August 2012 |archive-url=https://web.archive.org/web/20120808195305/http://www.nobelprize.org/nobel_prizes/physics/laureates/1915/ |url-status=live }}</ref><ref>{{harvnb|Cheney|Uth|Glenn|1999|p=120}}</ref> There were unsubstantiated rumors at the time that either Tesla or Edison had refused the prize.{{sfn|Cheney|2001|p=245}} The Nobel Foundation said, "Any rumor that a person has not been given a Nobel Prize because he has made known his intention to refuse the reward is ridiculous"; a recipient could decline a Nobel Prize only after he is announced a winner.{{sfn|Cheney|2001|p=245}}

There have been subsequent claims by Tesla biographers that Edison and Tesla were the original recipients and that neither was given the award because of their animosity toward each other; that each sought to minimize the other's achievements and right to win the award; that both refused ever to accept the award if the other received it first; that both rejected any possibility of sharing it; and even that a wealthy Edison refused it to keep Tesla from getting the $20,000 prize money.{{sfn|Seifer|2001|p=7}}{{sfn|Cheney|2001|p=245}}

In the years after these rumors, neither Tesla nor Edison won a Nobel prize (although Edison received one of 38 possible bids in 1915 and Tesla received one of 38 possible bids in 1937).{{sfn|Seifer|2001|pp=378–380}}

=== Other awards, patents and ideas ===
Tesla won numerous medals and awards over this time. They include:

* Grand Officer of the [[Order of St. Sava]] ([[Kingdom of Serbia|Serbia]], 1892)
* [[Elliott Cresson Medal]] ([[Franklin Institute]], US, 1894)<ref name="pg">{{cite book|last1=Goldman|first1=Phyllis|title=Monkeyshines on Great Inventors|date=1997|publisher=EBSCO Publishing, Inc.|location=Greensboro, NC|isbn=978-1-888325-04-1|page=15|url=https://books.google.com/books?id=SKOmiByD_X8C|language=en|access-date=14 May 2020|archive-date=23 March 2024|archive-url=https://web.archive.org/web/20240323123811/https://books.google.com/books?id=SKOmiByD_X8C|url-status=live}}</ref>
* Grand Cross of the [[Order of Prince Danilo I]] ([[Principality of Montenegro|Montenegro]], 1895)<ref>{{Cite book|last=Acović|first=Dragomir|title=Slava i čast: Odlikovanja među Srbima, Srbi među odlikovanjima|year=2012|location=Belgrade|publisher=Službeni Glasnik|pages=85}}</ref>
* Member of the [[American Philosophical Society]] (US, 1896)<ref>{{Cite web |title=APS Member History |url=https://search.amphilsoc.org/memhist/search?creator=Nikola+Tesla&title=&subject=&subdiv=&mem=&year=&year-max=&dead=&keyword=&smode=advanced |access-date=11 March 2024 |website=American Philosophical Society |archive-date=11 March 2024 |archive-url=https://web.archive.org/web/20240311152707/https://search.amphilsoc.org/memhist/search?creator=Nikola+Tesla&title=&subject=&subdiv=&mem=&year=&year-max=&dead=&keyword=&smode=advanced |url-status=live }}</ref>
* [[AIEE Edison Medal]] ([[Institute of Electrical and Electronics Engineers]], US, 1916)<ref name="EdisonMedal">{{cite web|title=IEEE Edison Medal Recipient List|url=https://www.ieee.org/content/dam/ieee-org/ieee/web/org/about/awards/recipients/edison_rl.pdf|publisher=Institute of Electrical and Electronics Engineers (IEEE)|access-date=4 June 2022|archive-date=28 January 2021|archive-url=https://web.archive.org/web/20210128155822/https://www.ieee.org/content/dam/ieee-org/ieee/web/org/about/awards/recipients/edison_rl.pdf|url-status=dead}}</ref>
* Grand Cross of the [[Order of St. Sava]] ([[Kingdom of Serbs, Croats and Slovenes|Yugoslavia]], 1926)<ref name="eserbia">{{cite web|title=Culture|url=http://www.eserbia.org/culture/lectures/288-nikola-tesla-and-the-serbian-orthodox-church-a-st-sava-s-day-reflection|website=www.eserbia.org|access-date=16 January 2017|archive-date=13 February 2017|archive-url=https://web.archive.org/web/20170213134050/http://www.eserbia.org/culture/lectures/288-nikola-tesla-and-the-serbian-orthodox-church-a-st-sava-s-day-reflection|url-status=live}}</ref>
* Cross of the [[Order of the Yugoslav Crown]] ([[Kingdom of Yugoslavia|Yugoslavia]], 1931)
* [[John Scott Medal]] ([[Franklin Institute]] & [[Philadelphia City Council]], US, 1934)<ref name=pg />
* [[Order of the White Eagle (Serbia)|Order of the White Eagle]] ([[Kingdom of Yugoslavia|Yugoslavia]], 1936)
* Grand Cross of the [[Order of the White Lion]] ([[Czechoslovakia]], 1937){{sfn|Cheney|2011|p=312}}
* Medal of the [[University of Paris]] (Paris, France, 1937)
* The Medal of the University St. Clement of Ochrida ([[Sofia, Bulgaria]], 1939)

[[File:Second banquet meeting of the Institute of Radio Engineers.jpg|thumb|Second banquet meeting of the Institute of Radio Engineers, 23 April 1915. Tesla is seen standing in the center.]]

Tesla attempted to market several devices based on the production of [[ozone]]. These included his 1900 Tesla Ozone Company selling an 1896 patented device based on his Tesla coil, used to bubble ozone through different types of oils to make a therapeutic gel.<ref>Anand Kumar Sethi (2016). ''The European Edisons: Volta, Tesla, and Tigerstedt'', Springer. pp. 53–54</ref> He also tried to develop a variation of this a few years later as a room sanitizer for hospitals.{{sfn|Carlson|2013|p=353}}

Tesla theorized that the application of electricity to the brain enhanced intelligence. In 1912, he crafted "a plan to make dull students bright by saturating them unconsciously with electricity," wiring the walls of a schoolroom and, "saturating [the schoolroom] with infinitesimal electric waves vibrating at high frequency. The whole room will thus, Mr. Tesla claims, be converted into a health-giving and stimulating electromagnetic field or 'bath.{{'-}}"<ref name="Gilliams">{{cite web |last1=Gilliams |first1=E. Leslie |title=Tesla's Plan of Electrically Treating Schoolchildren |url=http://www.teslacollection.com/tesla_articles/1912/popular_electricity_magazine/e_leslie_gilliams/tesla_s_plan_of_electrically_treating_school_children |via=teslacollection.com |work=Popular Electricity Magazine |date=1912 |access-date=19 August 2014 |archive-date=9 January 2015 |archive-url=https://web.archive.org/web/20150109004431/http://www.teslacollection.com/tesla_articles/1912/popular_electricity_magazine/e_leslie_gilliams/tesla_s_plan_of_electrically_treating_school_children |url-status=live }}</ref> The plan was, at least provisionally, approved by then superintendent of New York City schools, William H. Maxwell.<ref name="Gilliams" />

Before [[World War I]], Tesla sought overseas investors. After the war started, Tesla lost the funding he was receiving from his patents in European countries.

In the August 1917 edition of the magazine ''[[Electrical Experimenter]]'', Tesla postulated that electricity could be used to locate submarines via using the reflection of an "electric ray" of "tremendous frequency," with the signal being viewed on a fluorescent screen (a system that has been noted to have a superficial resemblance to modern [[radar]]).<ref>Margaret Cheney, Robert Uth, Jim Glenn, ''Tesla, Master of Lightning,'' pp. 128–129</ref> Tesla was incorrect in his assumption that high-frequency radio waves would penetrate water.<ref>{{cite book|url=https://books.google.com/books?id=W1JAeg1PiWIC&pg=PA154|title=Lewis Coe (2006). ''Wireless Radio: A History''. McFarland. p. 154|isbn=978-0-7864-2662-1|last1=Coe|first1=Lewis|date=8 February 2006|publisher=McFarland }}</ref> [[Émile Girardeau]], who helped develop France's first radar system in the 1930s, noted in 1953 that Tesla's general speculation that a very strong high-frequency signal would be needed was correct. Girardeau said, "(Tesla) was prophesying or dreaming, since he had at his disposal no means of carrying them out, but one must add that if he was dreaming, at least he was dreaming correctly".{{sfn|Cheney|2001|p=266}}

In 1928, Tesla received patent, {{US patent|1,655,114}}, for a [[biplane]] design capable of [[vertical take-off and landing]] (VTOL), which "gradually tilted through manipulation of the elevator devices" in flight until it was flying like a conventional plane.<ref>{{cite web |last=Tesla |first=Nikola |title=TESLA PATENT 1,655,114 APPARATUS FOR AERIAL TRANSPORTATION. |url=https://teslauniverse.com/nikola-tesla-patents-1,655,114-aerial-transportation |publisher=U.S. Patent Office |access-date=20 July 2012 |archive-date=20 July 2012 |archive-url=https://web.archive.org/web/20120720092018/http://www.teslauniverse.com/nikola-tesla-patents-1,655,114-aerial-transportation |url-status=live }}</ref> This impractical design was something Tesla thought would sell for less than $1,000.{{sfn|Cheney|2001|p=251}}<ref name="airspacemag">{{cite web |url=https://www.smithsonianmag.com/air-space-magazine/nikola-teslas-curious-contrivance-10187565/ |title='Nikola Tesla's Curious Contrivance' by A.J.S. RAYL Air & Space magazine, September 2006, reprint at History of Flight |publisher=airspacemag.com |access-date=10 September 2012 |archive-date=27 January 2022 |archive-url=https://web.archive.org/web/20220127184244/https://www.smithsonianmag.com/air-space-magazine/nikola-teslas-curious-contrivance-10187565/ |url-status=live }}</ref>

Tesla had a further office at 350 Madison Ave<ref>Valentine Korah, An Introductory Guide to EC Competition Law and Practice, Sweet & Maxwell – 1928, page 235</ref> but by 1928 he no longer had a laboratory or funding.<ref name="airspacemag" />

=== Living circumstances ===
Tesla lived at the [[Waldorf-Astoria (1893–1929)|Waldorf Astoria]] in New York City from 1900 and ran up a large bill.{{sfn|Cheney|Uth|Glenn|1999|p=125}} He moved to the [[St. Regis New York|St. Regis Hotel]] in 1922 and followed a pattern from then on of moving to a different hotel every few years and leaving unpaid bills behind.{{sfn|Carlson|2013|p=467-468}}{{sfn|O'Neill|1944|p=359}}

Tesla walked to the park every day to feed the pigeons. He began feeding them at the window of his hotel room and nursed injured birds back to health.{{sfn|O'Neill|1944|p=359}}<ref>{{cite web|title=About Nikola Tesla |url=http://www.teslasociety.org/about.html |publisher=Tesla Memorial Society of NY |access-date=5 July 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120525133151/http://www.teslasociety.org/about.html |archive-date=25 May 2012 }}</ref><ref>{{cite web |title=Tesla Life and Legacy&nbsp;– Poet and Visionary |url=https://www.pbs.org/tesla/ll/ll_poevis.html |publisher=PBS |access-date=5 July 2012 |archive-date=8 July 2012 |archive-url=https://web.archive.org/web/20120708101441/http://www.pbs.org/tesla/ll/ll_poevis.html |url-status=live }}</ref> He said that he had been visited by a certain injured white pigeon daily. He spent over $2,000 ({{Inflation|US|2000|1922|r=-1|fmt=eq}}) to care for the bird, including a device he built to support her comfortably while her broken wing and leg healed.{{sfn|Seifer|2001|p=414}} Tesla stated:

{{blockquote|I have been feeding pigeons, thousands of them for years. But there was one, a beautiful bird, pure white with light grey tips on its wings; that one was different. It was a female. I had only to wish and call her and she would come flying to me. I loved that pigeon as a man loves a woman, and she loved me. As long as I had her, there was a purpose to my life.<ref>{{cite web|title=About Nikola Tesla |url=http://www.teslasociety.org/about.html |publisher=Tesla Society of USA and Canada |access-date=5 July 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120525133151/http://www.teslasociety.org/about.html |archive-date=25 May 2012 }}</ref>}}

Tesla's unpaid bills, as well as complaints about the mess made by pigeons, led to his eviction from St. Regis in 1923. He was also forced to leave the [[Hotel Pennsylvania]] in 1930 and the Hotel Governor Clinton in 1934.{{sfn|O'Neill|1944|p=359}} At one point he also took rooms at the [[Hotel Marguery]].{{sfn|Cheney|Uth|Glenn|1999|p=135}}

Tesla moved to the [[Wyndham New Yorker Hotel|Hotel New Yorker]] in 1934. At this time Westinghouse Electric & Manufacturing Company began paying him $125 ({{Inflation|US|125|1934|r=-1|fmt=eq}}) per month in addition to paying his rent. Accounts of how this came about vary. Several sources claim that Westinghouse was concerned, or possibly warned, about potential bad publicity arising from the impoverished conditions in which their former star inventor was living.{{sfn|Jonnes|2004|p=365}}<ref>{{harvnb|Cheney|Uth|Glenn|1999|p=149}}</ref><ref name="Seifer435">{{harvnb|Seifer|2001|p=435}}</ref>{{sfn|Carlson|2013|p=379}} The payment has been described as being couched as a "consulting fee" to get around Tesla's aversion to accepting charity. Tesla biographer Marc Seifer described the Westinghouse payments as a type of "unspecified settlement".<ref name="Seifer435" />

=== Birthday press conferences ===
[[File:Nikola Tesla on Time Magazine 1931.jpg|thumb|Tesla on [[Time (magazine)|''Time'' magazine]] commemorating his 75th birthday]]
In 1931, a young journalist whom Tesla befriended, [[Kenneth M. Swezey]], organized a celebration for the inventor's 75th birthday.<ref>{{Cite web|url=http://www.davidjkent-writer.com/2012/07/10/happy-birthday-nikola-tesla-a-scientific-rock-star-is-born/|title=Happy Birthday, Nikola Tesla – A Scientific Rock Star is Born|last=Kent|first=David J.|date=10 July 2012|website=Science Traveler|language=en-US|access-date=26 January 2019|archive-date=26 January 2019|archive-url=https://web.archive.org/web/20190126221049/http://www.davidjkent-writer.com/2012/07/10/happy-birthday-nikola-tesla-a-scientific-rock-star-is-born/|url-status=live}}</ref> Tesla received congratulations from figures in science and engineering such as [[Albert Einstein]],<ref>{{cite web|url=http://www.teslasociety.com/time.jpg|title=Time front cover, Vol XVIII, No. 3|date=20 July 1931|access-date=10 September 2012|archive-date=7 July 2018|archive-url=https://web.archive.org/web/20180707163714/http://www.teslasociety.com/time.jpg|url-status=live}}</ref> and he was also featured on the cover of [[Time magazine|''Time'' magazine]].<ref>{{cite magazine |title=Nikola Tesla|url=http://www.time.com/time/covers/0,16641,19310720,00.html|archive-url=https://web.archive.org/web/20070708020011/http://www.time.com/time/covers/0,16641,19310720,00.html|url-status=dead|archive-date=8 July 2007|magazine=Time|access-date=2 July 2012}}</ref> The cover caption "All the world's his power house" noted his contribution to [[Electricity generation|electrical power generation]]. The party went so well that Tesla made it an annual event, an occasion where he would put out a large spread of food and drink—featuring dishes of his own creation. He invited the press in order to see his inventions and hear stories about his past exploits, views on current events, and sometimes baffling claims.{{sfn|Cheney|2001|p=151}}{{sfn|Carlson|2013|pp=380–382}}

[[File:Teslathoughtcamera.jpeg|thumb|Newspaper representation of the thought camera Tesla described at his 1933 birthday party]]
At the 1932 party, Tesla claimed he had invented a motor that would run on [[cosmic ray]]s.{{sfn|Carlson|2013|pp=380–382}}
In 1933, at age 77, Tesla told reporters at the event that, after 35 years of work, he was on the verge of producing proof of a new form of energy. He claimed it was a theory of energy that was "violently opposed" to Einsteinian physics and could be tapped with an apparatus that would be cheap to run and last 500 years. He also told reporters he was working on a way to transmit individualized private radio wavelengths, working on breakthroughs in [[metallurgy]], and developing a way to photograph the [[retina]] to record thought.<ref>Tesla Predicts New Source of Power in Year, New York Herald Tribune, 9 July 1933</ref>

At the 1934 occasion, Tesla told reporters he had designed a [[superweapon]] he claimed would end all war.<ref>{{cite magazine |title=Tesla's Ray |magazine=Time |date=23 July 1934}}</ref><ref name="seifer1">{{cite web |last=Seifer |first=Marc |title=Tesla's "Death Ray" Machine |url=http://www.bibliotecapleyades.net/tesla/esp_tesla_2.htm |publisher=bibliotecapleyades.net |access-date=4 July 2012 |archive-date=24 June 2006 |archive-url=https://web.archive.org/web/20060624171605/http://www.bibliotecapleyades.net/tesla/esp_tesla_2.htm |url-status=live }}</ref> He called it "[[teleforce]]", but was usually referred to as his [[death ray]].<ref>Cheney, Margaret & Uth, Robert (2001). Tesla: Master of Lightning. Barnes & Noble Books. p. 158</ref> In 1940, the ''[[New York Times]]'' gave a range for the ray of {{convert|250|mi}}, with an expected development cost of US$2&nbsp;million (equivalent to ${{Inflation|US|2|1940|r=2}}&nbsp;million in {{Inflation/year|US}}).<ref name="pmnyt1940">{{cite web |url=https://www.popularmechanics.com/science/energy/a44197280/did-the-us-government-steal-nikola-teslas-research/ |title=Did the U.S. Government Really Steal Nikola Tesla's Research Papers? |first=Jessica |last=Coulon |date=14 June 2023 |accessdate=26 June 2023 |work=[[Popular Mechanics]] |archive-date=26 June 2023 |archive-url=https://web.archive.org/web/20230626231358/https://www.popularmechanics.com/science/energy/a44197280/did-the-us-government-steal-nikola-teslas-research/ |url-status=live }}</ref> Tesla described it as a defensive weapon that would be put up along the border of a country and be used against attacking ground-based infantry or aircraft. Tesla never revealed detailed plans of how the weapon worked during his lifetime but, in 1984, they surfaced at the [[Nikola Tesla Museum]] archive in [[Belgrade]].{{sfn|Carlson|2013|p=382}} The treatise, ''The New Art of Projecting Concentrated Non-dispersive Energy through the Natural Media'', described an open-ended vacuum tube with a gas jet seal that allows particles to exit, a method of charging slugs of tungsten or mercury to millions of volts, and directing them in streams (through [[electrostatic]] repulsion).{{sfn|Carlson|2013|pp=380–382}}{{sfn|Seifer|1998|p=454}} Tesla tried to attract interest of the [[United States Department of Defense|US War Department]],<ref>"Aerial Defense 'Death-Beam' Offered to U.S. By Tesla" 12 July 1940</ref> United Kingdom, Soviet Union, and Yugoslavia in the device.<ref>{{cite web |last=Seifer |first=Marc J. |title=Tesla's "death ray" machine |url=http://www.bibliotecapleyades.net/tesla/esp_tesla_2.htm |access-date=5 September 2012 |archive-date=24 June 2006 |archive-url=https://web.archive.org/web/20060624171605/http://www.bibliotecapleyades.net/tesla/esp_tesla_2.htm |url-status=live }}</ref>

In 1935, at his 79th birthday party, Tesla covered many topics. He claimed to have discovered the cosmic ray in 1896 and invented a way to produce direct current by [[Inductive charging|induction]], and made many claims about his [[Tesla's oscillator|mechanical oscillator]].<ref name="ReferenceA">Earl Sparling, NIKOLA TESLA, AT 79, USES EARTH TO TRANSMIT SIGNALS: EXPECTS TO HAVE $100,000,000 WITHIN TWO YEARS, New York World-Telegram, 11 July 1935</ref> Describing the device (which he expected would earn him $100 million within two years) he told reporters that a version of his oscillator had caused an earthquake in his 46 East Houston Street lab and neighboring streets in [[Lower Manhattan]] in 1898.<ref name="ReferenceA" /> He went on to tell reporters his oscillator could destroy the [[Empire State Building]] with {{convert|5|lb}} of air pressure.{{sfn|Carlson|2013|p=380}} He also proposed using his oscillators to transmit vibrations into the ground. He claimed it would work over any distance and could be used for communication or locating underground mineral deposits, a technique he called "telegeodynamics".<ref name="Anderson" />

In 1937, at his Grand Ballroom of Hotel New Yorker event, Tesla received the [[Order of the White Lion]] from the Czechoslovak ambassador and a medal from the Yugoslav ambassador. On questions concerning the death ray, Tesla stated: "But it is not an experiment&nbsp;... I have built, demonstrated and used it. Only a little time will pass before I can give it to the world."{{sfn|Carlson|2013|pp=380–382}}