Collection of 50 original patents.

Washington DC: Norris-Peters Co., 1886-1914.

An extraordinary collection of patents from Tesla’s most fruitful period, comprising almost half of all the patents granted to him. The collection includes Tesla’s patent (645,576) for the invention of radio, one of the key technological inventions of the last century – this was disputed by Marconi, but almost half a century later the US Supreme Court ruled that Tesla had priority. Further important patents in the collection include that for the ‘Tesla coil’ (462,418), which was the basis of his method of wireless power transmission; for remote-controlled devices (613,809), which anticipated robotics; and those for his systems of power transmission, AC motors, generators, incandescent arc-lighting, transformers, etc. In 1980, John T. Ratzlaff published Dr. Nikola Tesla. Selected Patent Wrappers from the National Archives. He wrote: “Twenty of the Tesla patent wrappers have been selected for this publication on the basis of importance and current interest.’ Of these 20 patents, 16 are in the present collection. Tesla described the principle of radio communication, and gave a demonstration, in a famous lecture at St. Louis in 1893, but due to various personal difficulties he did not file a patent for radio until 1897. “At St. Louis [Tesla] made the first public demonstration ever of radio communication, although Marconi is generally credited with having achieved this feat in 1895” (Cheney, p. 68). “What Tesla described in this lecture should be taken to be the foundation of radio engineering” (Sarkar, p. 271). “He was an inventor, an engineer, a scientist and an oddball. It was Tesla, not Marconi who invented radio … more than any one man, Nikola Tesla is responsible for the twentieth century” (Hunt, introduction to Nikola Tesla: My Inventions and Other Writings (2011)). In his speech presenting Tesla with the Edison medal in 1917, B. A. Behrend, Vice President of the American Institute of Electrical Engineers, stated: “Were we to seize and eliminate from our industrial world the result of Mr. Tesla’s work, the wheels of industry would cease to turn, our electric cars and trains would stop, our towns would be dark and our mills would be idle and dead. His name marks an epoch in the advance of electrical science.” “Patents issued to Nikola Tesla represent the culmination of his creative efforts and, therefore, must be considered as a basic source of information … The contents are of the greatest importance to the understanding of Tesla’s inventions and discoveries, some of which were made nearly a century ahead of their time” (Ratzlaff, pp. vii-viii). These patents are the originals issued by the US Patent and Trademark Office (USPTO). At least two copies of a patent would be sent to the applicant, or more usually their attorneys. According to the archivist at the USPTO, these copies of Tesla’s patents are very probably those sent by the USPTO to his attorneys. Evidence includes the three staples (as on all original copies the Office would send to the Applicant), the annotations on the front of each patent and the lack of any additional printing on the documents. Some of the patents have the name of the printer, the Norris-Peters Company of Washington DC who printed the patents for the USPTO. All of these patents are of extreme rarity. We have been unable to locate any other copies, other than the original ‘Letters patent’ issued by the USPTO and now held at the US National Archives. None are listed on OCLC, and only one Tesla patent (a minor one relating to his system of AC power transmission) has ever appeared at auction.

A list of the patents follows (the first date is when the patent was filed; the second is when it was granted). Those with a * were selected by Ratzlaff for their importance.
1. 334,823. Commutator for Dynamo-Electric Machines. May 6, 1885; January 26, 1886. 2 pp.
2. 335,786. Electric-Arc Lamp. July 13, 1885; February 9, 1886. 5 pp.
3. 455,069. Electric Incandescent Lamp. May 14, 1891; June 30, 1891. 3 pp.
4. 462,418. Method of and Apparatus for Electrical Conversion and Distribution. February 4, 1891; November 3, 1891. 4 pp.
5. 464,666. Electro-Magnetic Motor. July 13, 1891; December 8, 1891. 3 pp.
6. 464,667. Electrical Condenser. August 1, 1891; December 8, 1891. 2 pp.
7. 487,796. System of Electrical Transmission of Power. May 15, 1888; December 13, 1892. 6 pp.
8. 511,559. Electrical Transmissions of Power. December 8, 1888; December 26, 1893. 3 pp.
9. 511,560. System of Electrical Power Transmission. December 8, 1888; December 26, 1893. 6 pp.
10. 511,915. Electrical Transmission of Power. May 15, 1888; January 2, 1894. 3 pp.
11*. 511,916. Electric Generator. August 19, 1893; January 2, 1894. 6 pp.
12*. 512,340. Coil for Electro-Magnets. July 7, 1893; January 9, 1894. 3 pp.
13. 514,167. Electrical Conductor. January 2, 1892; February 6, 1894. 3 pp.
14. 514,168. Means for Generating Electric Currents. August 2, 1893; February 6, 1894. 3 pp.
15*. 514,169. Reciprocating Engine. August 19, 1893; February 6, 1894. 4 pp.
16. 514,170. Incandescent Electric Light. January 2, 1892; February 6, 1894. 3 pp.
17. 514,972. Electric-Railway System. January 2, 1892; February 20, 1894. 3 pp.
18. 514,973. Electrical Meter. December 15, 1893; February 20, 1894. 3 pp.
19*. 568,176. Apparatus for Producing Electric Currents of High Frequency and Potential. April 22, 1896; September 22, 1896. 4 pp.
20. 568,177. Apparatus for Producing Ozone. June 17, 1896; September 22, 1896. 4 pp.
21. 568,178. Method of Regulating Apparatus for Producing Currents of High Frequency. June 20, 1896; September 22, 1896. 5 pp.
22. 568,179. Method of and Apparatus for Producing Currents of High Frequency. July 6, 1896; September 22, 1896. 4 pp.
23*. 568,180. Apparatus for Producing Electrical Currents of High Frequency. July 9, 1896; September 22, 1896. 4 pp.
24. 577,670. Apparatus for Producing Electrical Currents of High Frequency. September 3, 1896; February 23, 1897. 4 pp.
25. 577,671. Manufacture of Electrical Condensers, Coils, &c. November 5, 1896; February 23, 1897. 3 pp.
26. 583,953. Apparatus for Producing Currents of High Frequency. October 19, 1896; June 8, 1897. 3 pp.
27. 593,138. Electrical Transformer. March 20, 1897; November 2, 1897. 4 pp.
28. 609,245. Electrical-Circuit Controller. December 2, 1897; August 16, 1898. 5 pp.
29. 609,246. Electric-Circuit Controller. February 28, 1898; August 16, 1898. 4 pp.
30. 609,247. Electric-Circuit Controller. March 12, 1898; August 16, 1898. 3 pp.
31. 609,248. Electric-Circuit Controller. March 12, 1898; August 16, 1898. 3 pp.
32. 609,249. Electrical-Circuit Controller. March 12, 1898; August 16, 1898. 3 pp.
33. 609,250. Electrical Igniter for Gas-Engines. June 15, 1898; August 16, 1898. 3 pp.
34. 609,251. Electrical-Circuit Controller. June 15, 1898; August 16, 1898. 5 pp.
35. 611,719. Electrical-Circuit Controller. December 10, 1897; October 4, 1898. 5 pp.
36. 613,735. Electric-Circuit Controller. April 19, 1898; November 8, 1898. 5 pp.
37*. 613,809. Method of and Apparatus for Controlling Mechanism of Moving Vessels or Vehicles. July 1, 1898; November 8, 1898. 13 pp.
38*. 645,576. System of Transmission of Electrical Energy. September 2, 1897; March 20, 1900. 7 pp.
39*. 649,621. Apparatus for Transmission of Electrical Energy. September 2, 1897; March 15, 1900. 4 pp.
40. 11,865. Method of Insulating Electric Conductors. August 14, 1900; October 23, 1900. 6 pp.
41*. 685,012. Means for Increasing the Intensity of Electrical Oscillations. March 21, 1900; October 22, 1901. 4 pp.
42*. 685,953. Method of Intensifying and Utilizing Effects Transmitted through Natural Media. June 24, 1899; November 5, 1901. 6 pp.
43*. 685,954. Method of Utilizing Effects Transmitted through Natural Media. August 1, 1899; November 5, 1901. 9 pp.
44*. 685,955. Apparatus for Utilizing Effects Transmitted from a Distance to a Receiving Device through Natural Media. June 24, 1899; November 5, 1901. 7 pp.
45*. 685,956. Apparatus for Utilizing Effects Transmitted through Natural Media. August 1, 1899; November 5, 1901. 8 pp.
46. 685,957. Apparatus for the Utilization of Radiant Energy. March 21, 1901; November 5, 1901. 5 pp.
47. 685,958. Method of Utilizing Radiant Energy. March 21, 1901; November 5, 1901. 4 pp.
48*. 723,188. Method of Signaling. July 16, 1900; March 17, 1903. 5 pp.
49*. 787,412. Art of Transmitting Electrical Energy through the Natural Mediums. May 16, 1900; April 18, 1905. 6 pp.
50*. 1,119,732. Apparatus for Transmitting Electrical Energy. January 18, 1902; December 1, 1914. 4 pp.

“Nikola Tesla was born in Smiljan, Lika [now Croatia] in 1856 as the fourth child of Milutin and Djuka Tesla. His father was a well-educated priest of the Serbian Orthodox Church. Nikola’s mother was also intelligent and talented and he often said that his mother influenced his life as an inventor. His technical education was limited to two years polytechnic studies at Gratz, Styria [now Austria], where he devoted himself to mathematics, physics and mechanical engineering. From Gratz he went to Prague with the object of completing his scientific education and philosophical studies at the University. From Prague he went to Budapest to work in a new telephone company. It was there that in 1882 he invented his induction motor and an alternating-current (AC) system of power transmission. Seeking better opportunities to find people who were interested in his invention, he accepted a position of electrical engineer for a French company in Paris, where he remained for two years. Another important step in his life was acceptance of the position of designer to build direct current dynamos and motors for the Edison Company in New York, where he arrived in 1884 in the hope of finding the ‘the land of golden promise’. Edison was not interested in Tesla’s alternating currents system and Tesla soon left Edison, after a bitter struggle” (Sarkar, pp. 267-268).

“No sooner had Tesla left the Edison organization than he was approached by Benjamin A. Vail from Rahway and Robert Lane, a businessman from East Orange, New Jersey … Excited by the prospects of electric lighting, Vail and Lane were keen to enter this new field. In December 1894, Vail and Lane hired Tesla and they organized the Tesla Electric Light and Manufacturing Company” (Carlson, p. 73). “It was not until he formed the new Tesla Electric Company [that Tesla was able] to realize his inventions and develop working models of motors, generators and transformers … Many of these inventions were later ‘reinvented’ by others without referring to Tesla” (Sarkar, p. 269).

“Working in his first laboratory on Grand Street, the Serb developed a Tesla arc lamp which was more simple, reliable, safe, and economical than those in current use. The system was patented and put to use on the streets of Rahway” (Cheney, p. 36). This resulted in Tesla’s first two patents, 334,823 (1) and 335,786 (2) – the former was the first to be granted but the latter was the first to be submitted. (Numbers in brackets refer to the list of patents in the collection – see below.)

Following this success, Tesla was eased out of the company by Vail and Lane, and entered one of the most depressing periods of his life. In the spring of 1887, however, he met A. K. Brown, manager of the Western Union Telegraph Company. Brown was interested in Tesla’s ideas about AC power transmission, and they formed a new company, the Tesla Electric Company, with the goal of developing the AC system. It was based only a few blocks from Edison’s workshops in New York City. Thus began the ‘war of the currents,’ between Edison’s DC system and Tesla’s AC system of power transmission. Only one patent in the collection refers to this ‘war’, patent 464,666 (5), the very last patent granted to Tesla for his ‘polyphase’ AC system.

“In 1890-1891, … having successfully delivered his polyphase induction system, he would seek the means to deliver power wirelessly. Second, he would try to invent new methods of illumination. And third, he would investigate the wireless transmission of intelligence. These broad goals established the direction of work that would occupy Tesla for the next 50 years.

“The pursuit of wireless transmission began at his Grand Street lab as he was busy exploring Hertz’s work on high-frequency electromagnetic waves. Tesla was determined to increase the frequency of electrical vibrations … Tesla reasoned that if he could build a device that continuously emits electricity at higher frequencies, he would be able to achieve important technical advantages. Among these would be lamps that glow more brilliantly and the ability to transmit energy more efficiently. Tesla began his high-frequency investigations by replacing Hertz’s apparatus for giving off an electric spark and propagating electromagnetic waves in space. At the heart of Hertz’s machine was a large induction coil, consisting of an iron core would with two different thicknesses of wire. A battery with one lead would be connected to the iron core, and the other lead would run to a telegraph key. That, in turn, would be connected to the thicker of the two wires (primary). Each of two leads – one running from the thinner wire (secondary) and one running from the iron core – would be attached to each of two electrodes, with a gap separating them. Every time current flowing from the battery to the telegraph key was turned on or off, the induction coil produced high-voltage sparks between the two electrodes.

“Into this apparatus, Tesla introduced a capacitor and took to manipulating the induction coil in and out. Eventually he would remove the iron core and rely on air cores for separate windings of both the primary and secondary wires, which were tuned to resonate. He would also replace the battery with an AC generator, as well as a step-up transformer … Tesla was attempting to manipulate the vibrations of every capacitor discharge and obtain higher voltages from the current produced by an induction coil. Tinkering in this way finally enabled him to control the amount of discharge as well as the frequency. He called his machine an oscillating generator. His findings were reflected in his application for Tesla patent 462,418 – ‘Method of and apparatus for electrical conversion and distribution,’ filed on February 4, 1891. It was granted on November 3, 1891. The invention would ultimately become known as the Tesla coil. With its primary and secondary circuits both tuned to vibrate in harmony, the Tesla coil would be one of his greatest inventions. It would be used in various forms for the future of radio and television” (Sutherland-Cohen, pp. 64-67).

The present collection contains patent 462,418 (4) on the invention of the Tesla coil, as well as the following patents giving further developments and refinements of the same device: 6, 12, 13, 14, 19-24, 26-32, 34-36, 40-46, 48-50.

In several spectacular public lectures in 1893, Tesla showed how the Tesla coil could be used to produce a wireless lighting system, lighting Geissler tubes and even incandescent light bulbs from across a stage with no intervening wires. These demonstrations did not lead to commercial products, but they made Tesla famous.

A more serious proposal, to use wireless transmission to power electric trains, is described in patent 514,972 (17). Electric streetcars were a common sight in Tesla’s day. One major flaw in cars’ systems was the rolling or sliding contact that transferred electricity from the lines to the car. In his patent for an Electric Railway System, Tesla proposed a form of underground wireless power transmission. The power is conducted down a buried channel in which the streetcar’s J-shaped lead passes to pick up and transfer the energy to the car.

“Tesla’s work on high-frequency currents led to a number of discoveries that he never patented. Among the by-products are modern electric clocks, x-ray photography, and therapeutic deep-heat healing effects that laid the foundation for the medical field of diathermy” (ibid., p. 70).

On March 13, 1895 Tesla’s New York laboratory was burned, and he had to move to new premises on Houston Street. This stopped his research in the field of high frequency currents for some time. “After the lectures on 1893 in which he had described in detail the six basic requirements of radio transmission and reception, he had built equipment that could be operated between his laboratory and various points with New York City. The fire had destroyed all this and had set back his research, but by the spring of 1897 … he was prepared to move ahead” (Cheney, p. 109).

“The scientist who, next to Tesla, most deserved credit for pioneering radio was Sir Oliver Lodge, for in 1894 he demonstrated the possibility of transmitting telegraph signals wirelessly by Hertzian waves a distance of 150 yards. Two years later, young Marchese Guglielmo Marconi arrived in London with a wireless set identical to Lodge’s … He [had] a ground connection and antenna or aerial wire with which he had made crude experiments in Bologna. As it happened, this equipment was exactly what Tesla had described in his widely published lecture in 1893, which had been translated into many languages. Later … Marconi was to deny that he had ever read of Tesla’s system, and the US Patent Examiner was to brand his denial patently absurd” (Cheney, p. 69).

“On September 2, 1897 Tesla filed the patent application No. 650,343, subsequently granted as patent No. 645,576 (38) of March 20, 1900 and patent No. 649,621 (39) of May 15, 1900. The two patents by which Tesla protected his system and apparatus for wireless transmission are known as ‘system of four tuned circuits’. This fact is particularly important in the history of radio. They were the subject of a long lawsuit brought by the Marconi Wireless Telegraph Company of America against the United States of America, alleging that they have used wireless devices that infringed on Marconi patent No. 763,772 of June 28, 1904 [which was filed on November 10, 1900, a few months after Tesla’s had been granted] … the United States Supreme Court on June 21, 1943 invalidated the fundamental American radio patent of Marconi No. 763,772 … The Supreme Court cited Tesla’s system in its deliberations:

“The Tesla patent No. 645,576, applied for September 2, I897 and allowed March 20, 1900, disclosed a four circuit system, having two circuits each at transmitter and receiver, and recommended that all four circuits be tuned to the same frequency. Tesla’s apparatus was devised primarily for transmission of energy of any form of energy-consuming device by using the rarefied atmosphere at high elevations as a conductor when subjected to the electrical pressure of a very high voltage. But he also recognized that his apparatus could, without change, be used for wireless communication, which is dependent upon the transmission of electrical energy. His specifications declare: ‘The apparatus which I have shown will obviously have many other valuable uses – as, for instance, when it is desired to transmit intelligible messages to great distances …’” (Sarkar, pp. 274-275).

Tesla was the first to patent the technology of radio communication, but it was Marconi who successfully commercialized it and was rewarded with the Nobel Prize in Physics 1909, shared with Karl Ferdinand Braun “in recognition of their contributions to the development of wireless telegraphy.” A persistent rumour is that Edison and Tesla were to be jointly awarded the 1915 Prize but that each refused to share it with the other and so neither received it (the 1915 Prize was actually awarded to William and Lawrence Bragg, father and son).

At about the same time as Tesla was filing his patents for radio, he filed another in a field in which he was almost a century ahead of his time – robotics. “Tesla soon realized that if he could power devices such as lamps at a distance, he could also turn them on and off and thus control them. But rather than just control lamps, why not create an automaton, or what we might call a robot? To test out this idea, Tesla began building a prototype and chose to design a boat in response to the naval armaments race then underway. In the 1890s, the dominant naval power, Britain, was building a new fleet of battleships superior to the combined fleets of France and Russia. As these three nations raced to build new ships, so the United States, Germany, Spain and Japan followed suit in order to protect themselves. Powered by new triple-expansion steam engines and protected by steel armor, and armed with 12-inch guns, these new warships looked invincible. Tesla designed an unmanned torpedo boat that could carry an explosive charge and be directed by radio waves. One visitor to Tesla’s laboratory offered the following description of the boat:

‘Mr. Tesla explained that the boat contained the propelling machinery, consisting of an electric motor actuated by a storage battery in the hold, another motor to actuate the rudder and the delicate mechanism which performs the function of receiving . . . the electric impulses sent through the atmosphere from the distant operating station, which set in motion the propelling and steering motors, and through them . . . fire the exploding charge . . . in response to signals sent by the operator. ‘Now watch,’ said the inventor, and going to a table on the other side of the room on which lay a little switchbox, about five inches square, he gave the lever a sharp turn. Instantly the little bronze propeller began to revolve at a furious rate. ‘Now I will send the boat to starboard,’ he said, and another quick movement of the lever sent the helm sharp over, and another movement turned it as rapidly back again. At another signal the screw stopped and reversed’” (Forbes).

The inventor did nor disclose more than his fundamental idea in his basic patent No. 613,809 (37) – a means he had learned to use to protect his discoveries … The remarkable stage of development to which he had carried wireless, the forerunner of modern radio, would have been quite enough; but to introduce automation simultaneously, as he did, was probably too great a leap. On that day in 1898 when he demonstrated the common ancestor of modern guided weapons and vehicles, of automated industry, and of robotics, he was introducing an idea for which the world would not be ready for many years” (Cheney, p. 124).

From the 1890s through 1906, Tesla spent much of his time and fortune on a series of projects trying to develop the transmission of electrical power without wires. It was an expansion of his idea of using his Tesla coil to transmit power that he had been demonstrating in wireless lighting. He saw this as a way to transmit large amounts of power around the world. By the mid-1890s, Tesla was working on the idea that he might be able to conduct electricity long distances through the Earth or the atmosphere, and began working on experiments to test this idea including setting up a large resonance transformer magnifying transmitter in his Houston Street lab. He proposed a system of balloons suspending, transmitting, and receiving, electrodes in the air above 30,000 feet in altitude, where he thought the lower pressure would allow him to send high voltages (millions of volts) long distances. To further study the conductive nature of low-pressure air, Tesla set up an experimental station at high altitude in Colorado Springs during 1899. To fund his experiments, he convinced John Jacob Astor IV to invest $100,000. Astor thought he was primarily investing in the new wireless lighting system, but Tesla used the money to fund his Colorado Springs experiments. Patents 42-47 refer to results obtained in these experiments.

“Having become obsessed with the wireless transmission of energy, around 1900 Tesla set to work on his boldest project yet: to build a wireless global communication system – to be transmitted through a large electrical tower – for sharing information and providing free electricity throughout the world. With funding from a group of investors that included financial giant J. P. Morgan, in 1901 Tesla began work on the project in earnest, designing and building a lab with a power plant and a massive transmission tower on Long Island, New York, that became known as Wardenclyffe” (Hunt).

Two of the most important patents referring to the Wardenclyffe experiments are included in the present collection: patent 787,412 (49) describes Tesla’s proposed mechanism of transmitting electrical signals through the Erath, while 1,119,73249 (50), filed in 1902 but not issued until 1914, gives a detailed description and illustration of the Wardenclyffe tower itself.

“However, doubts arose among his investors about the plausibility of Tesla’s system. As his rival, Guglielmo Marconi – with the financial support of Andrew Carnegie and Thomas Edison – continued to make great advances with his own radio technologies, Tesla had no choice but to abandon the project … Two years later Tesla declared bankruptcy … Poor and reclusive, Nikola Tesla died on January 7, 1943, at the age of 86, in New York City, where he had lived for nearly 60 years” (Hunt).

Several lesser-known gems are also included in this collection.

Patents 11,865 (40) and 685,012 (41) show Tesla to have anticipated the field of cryogenics. “The first patent he filed on his return [to New York City from Colorado Springs] (No. 685,012) was a means for increasing the intensity of electrical oscillations, the medium for doing so being liquefied air to cool the coil and thus reduce its electrical resistance. He also received two other patents in 1900 and 1901 related to buried power transmission lines and the method of insulating them by freezing a surrounding dielectric medium such as water. One, a reissued patent (No. 11,865), referred to a ‘gaseous’ cooling agent – apparently a key word that had been inadvertently omitted from his original patent No. 655,838. He was therefore one of the originators of cryogenic engineering.

“Many years later, in the 1970s, developmental projects were initiated in America, Russia, and Europe for methods of using superconductors to transmit underground bulk electrical power, employing various cryogenic enclosures … The similarity moves closer, however, when considering Tesla’s patent No. 685,012, in which he describes the supercooling of conductors to appreciably lower their resistance, thereby minimizing their dissipation when conducting current. This is yet another instance in which his pioneer work had gone unacknowledged” (Cheney, pp. 152-153).

In his patents 685,957 (46) and 685,958 (47), Tesla describes a precursor to modern solar cell technology and other photoelectric devices. It consisted of a polished metal plate which was exposed to radiant energy (e.g., sunlight). The photoelectric effect causes electrons to be ejected from the plate which therefore becomes positively charged – Tesla wrongly believed that this was because sources of radiant energy such as the Sun emit positively charged particles which fall on the plate, but the net result is the same. When the plate was “connected to one of the terminals of a condenser while the other terminal of the same is made by independent means to receive or to carry away electricity a current flows into the condenser so long as the insulated body is exposed to the rays, and under the conditions hereinafter specified an indefinite accumulation of electrical energy in the condenser takes place. This energy after a suitable time interval, during which the rays are allowed to act, may manifest itself in a powerful discharge, which may be utilized for the operation or control of mechanical or electrical devices or rendered useful in many other ways” (from patent 685,957).

Patent 723,188 (48) demonstrates that Tesla foresaw modern logical computer circuitry. “Inventors of modern computer technology in the last half of the twentieth century repeatedly have been surprised, when seeking patents, to encounter Tesla’s basic ones, already on file. Leland Anderson, foe example, states that Tesla’s priority was first pointed out to him years ago by a patent attorney for a major computer firm with which he was associated in a research and development capacity. Anderson writes, ‘I am puzzled by the reluctance of some in the computer technology field to acknowledge Tesla’s priority in this regard in contrast to the adulation given to Messrs. Brattain, Bardeen, and Shockley for the invention of the transistor which made electronic computers a reality.’ Their patents and the Tesla patents … are combined to produce the physical embodiment of a solid-state AND gate. Computer systems contain thousands of logic decision elements called ANDs and ORs. All operations are performed by a computer are achieved through a system design utilizing these logic elements. ‘Tesla’s patents 723,188 and 725,605,’ says Anderson, ‘contain the basic principles of the logical AND circuit element … Thus,’ declares Anderson, ‘the subject of early Tesla patents, which were designed to achieve interference protection from outside influences in the command of radio-controlled weapons, have proved to be an obstacle for anyone attempting to obtain a basic logical AND circuit element patent in this era of modern computer technology” (Cheney, pp. 130-131).

Anderson, Priority in invention of radio, Tesla v. Marconi, Antique Wireless Association, March, 1980, Monograph New Series No. 4. Carlson, Tesla. Inventor of the Electrical Age, 2013. Cheney, Tesla. Man Out of Time, 2001. Sarkar et al, History of Wireless, 2006. Sutherland-Cohen, Tesla for Beginners, 2016.

Fifty separate patents (290 x 203 mm), each of 3-7 pages with at least one drawing with schematics. Each has an annotated note in a contemporary hand on the front blank leaf indicating the patent holder (Tesla), the patent number, and often the date the application was filed, date of issuance and date of expiration. Some have underlining in the text.

Item #5014

Price: $150,000.00