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 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.
Bladeless turbine On his 50th birthday, in 1906, Tesla demonstrated a 16,000 rpm
bladeless turbine. During 1910–1911, at the
Waterside Power Station in New York, several of his bladeless turbine engines were tested at 100–5,000 hp. Tesla worked with several companies including from 1919 to 1922 in
Milwaukee, for
Allis-Chalmers. Tesla licensed the idea to a precision instrument company, and it found use in the form of luxury car
speedometers and other instruments.
Wireless lawsuits When
World War I broke out, the British cut the transatlantic telegraph cable linking the U.S. to
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 U.S. by having the U.S. Marconi Company sue the German radio company
Telefunken for patent infringement. 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 U.S. entered the war against Germany in 1917. 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 U.S. in 1897, but his 1900 patent submission covering improvements to radio transmission had been rejected several times on the grounds that it infringed on other existing patents, including two 1897 Tesla wireless power tuning patents, before it was finally approved in 1904. Tesla's 1915 case went nowhere, but in a related case, where the Marconi Company tried to sue the U.S. government over WWI patent infringements, a
Supreme Court of the United States 1943 decision restored the prior patents of
Oliver Lodge,
John Stone, and Tesla. 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.
Other ideas 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 oil to make a therapeutic gel. He tried to develop a variation of this a few years later as a room sanitizer for hospitals. He 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." The plan was, at least provisionally, approved by then superintendent of New York City schools, William H. Maxwell. In the August 1917 edition of the magazine
The 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). Tesla was incorrect in his assumption that high-frequency radio waves would penetrate water.
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". In 1928, Tesla received patent , 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. This impractical design was something Tesla thought would sell for less than $1,000.
Living circumstances Tesla lived at the Waldorf Astoria Hotel in New York City from 1900 and ran up a large bill. He moved to the
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. 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. He said that he had been visited by a certain injured white pigeon daily. He spent over $2,000 () to care for the bird, including a device he built to support her comfortably while her broken wing and leg healed. 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 forced to leave the
Hotel Pennsylvania in 1930 and the Hotel Governor Clinton in 1934. At one point he took rooms at the
Hotel Marguery. Tesla moved to the
Hotel New Yorker in 1934. At this time, Westinghouse Electric & Manufacturing Company began paying him $125 () 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. 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". Tesla received congratulations from figures in science and engineering such as
Albert Einstein, and he was also featured on the cover of
Time magazine. The cover caption "All the world's his power house" noted his contribution to
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. At the 1932 party, Tesla claimed he had invented a motor that would run on
cosmic rays. 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. At the 1934 occasion, Tesla told reporters he had designed a
superweapon he claimed would end all war. It was referred to as his death beam or
death ray and papers cited Tesla's claims that it was a defensive weapon that would protect a country's border and could destroy an invading army 200 miles away and bring down a fleet of 10,000 enemy planes 250 miles away. Tesla used the name
Teleforce at his 1940 birthday meeting but never revealed to the press of how the weapon worked. The US suspected Tesla planned to sell the weapon to the
League of Nations and later, as threats of war increased, Tesla sent diagrams to the
U.S. War Department, United Kingdom, Soviet Union, and Yugoslavia. Plans that surfaced at the
Nikola Tesla Museum archive in
Belgrade. in 1984 described a device using a method of charging slugs of tungsten or mercury to millions of volts and directing them in streams (through
electrostatic repulsion) through an array open-ended gas jet seal vacuum tubes. 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
induction, and made many claims about his mechanical oscillator. 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. In 1937, at his event in the Grand Ballroom of the Hotel New Yorker, 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 ... I have built, demonstrated and used it. Only a little time will pass before I can give it to the world." == Awards ==