03 sept. 2017










Marchese Guglielmo Marconi (25 April 1874 – 20 July 1937) was an Italian inventor, best known for his development of a radiotelegraph system, which served as the foundation for the establishment of numerous affiliated companies worldwide. He shared the 1909 Nobel Prize in Physics with Karl Ferdinand Braun, „in recognition of their contributions to the development of wireless telegraphy”. Later in life, Marconi was an active Italian Fascist and an apologist for their ideology (such as the attack by Italian forces in Ethiopia).


Early years
Marconi was born near Bologna, Italy, the second son of Giuseppe Marconi, an Italian landowner, and his Irish wife, Annie Jameson, granddaughter of the founder of the Jameson Whiskey distillery. Marconi was educated in Bologna in the lab of Augusto Righi, in Florence at the Istituto Cavallero, and, later, in Livorno. As a child Marconi did not do well in school. Baptized as a Catholic, he was a member of the Anglican Church.

Radio work
During his early years, Marconi had an interest in science and electricity. One of the scientific developments during this era came from Heinrich Hertz, who, beginning in 1888, demonstrated that one could produce and detect electromagnetic radiation—now generally known as „radio waves”, at the time more commonly called „Hertzian waves” or „aetheric waves”. Hertz’s death in 1894 brought published reviews of his earlier discoveries, and a renewed interest on the part of Marconi. He was permitted to briefly study the subject under Augusto Righi, a University of Bologna physicist who had done research on Hertz’s work.

Early experimental devices
Marconi began to conduct experiments, building much of his own equipment in the attic of his home at the Villa Griffone in Pontecchio, Italy. His goal was to use radio waves to create a practical system of „wireless telegraphy”—i.e. the transmission of telegraph messages without connecting wires as used by the electric telegraph. This was not a new idea—numerous investigators had been exploring wireless telegraph technologies for over 50 years, but none had proven commercially successful. Marconi did not discover any new and revolutionary principle in his wireless-telegraph system, but rather he assembled and improved an array of facts, unified and adapted them to his system.[4] Marconi’s system had the following components:

A relatively simple oscillator, or spark producing radio transmitter, which was closely modeled after one designed by Righi, in turn similar to what Hertz had used;
A wire or capacity area placed at a height above the ground;
A coherer receiver, which was a modification of Edouard Branly’s original device, with refinements to increase sensitivity and reliability;
A telegraph key to operate the transmitter to send short and long pulses, corresponding to the dots-and-dashes of Morse code; and
A telegraph register, activated by the coherer, which recorded the received Morse code dots and dashes onto a roll of paper tape.
Similar configurations using spark-gap transmitters plus coherer-receivers had been tried by others, but many were unable to achieve transmission ranges of more than a few hundred metres. This was not the case for all researchers in the field of the wireless arts, though. [6][7]

At first, Marconi could only signal over limited distances. In the summer of 1895 he moved his experimentation outdoors. After increasing the length of the transmitter and receiver antennas, and arranging them vertically, and positioning the antenna so that it touched the ground, the range increased significantly.[8] (Although Marconi may not have understood until later the reason, the „ground connections” allowed the earth to act as a waveguide resonator for the surface wave signal.[9]) Soon he was able to transmit signals over a hill, a distance of approximately 1.5 km (0.9 mi). By this point he concluded that with additional funding and research, a device could become capable of spanning greater distances and would prove valuable both commercially and militarily.

Finding limited interest in his work in Italy, in early 1896 at the age of 21, Marconi traveled to London, England, accompanied by his mother to seek support for his work. (Marconi spoke fluent English in addition to Italian.) While there, he gained the interest and support of William Preece, the Chief Electrical Engineer of the British Post Office. The apparatus that Marconi possessed at that time was strikingly similar to that of one in 1882 by A. E. Dolbear, of Tufts College, which used a spark coil generator and a carbon granular rectifier for reception.[10][11] A series of demonstrations for the British government followed—by March, 1897, Marconi had transmitted Morse code signals over a distance of about 6 km (3.7 mi) across the Salisbury Plain. On 13 May 1897, Marconi sent the first ever wireless communication over water. It transversed the Bristol Channel from Lavernock Point (South Wales) to Flat Holm Island, a distance of 6 km (3.7 mi). The message read „Are you ready”. [12]. The receiving equipment was almost immediately relocated to Brean Down Fort on the Devon coast, stretching the range to 16 km (10 mi).

Impressed by these and other demonstrations, Preece introduced Marconi’s ongoing work to the general public at two important London lectures: „Telegraphy without Wires”, at the Toynbee Hall on 11 December 1896; and „Signalling through Space without Wires”, given to the Royal Institute on 4 June 1897.

Numerous additional demonstrations followed, and Marconi began to receive international attention. In July, 1897 he carried out a series of tests at La Spezia in his home country, for the Italian government. A test for Lloyds between Ballycastle and Rathlin Island, Ireland, was conducted on 6 July 1898. The English channel was crossed on 27 March 1899, from Wimereux, France to South Foreland Lighthouse, England, and in the fall of 1899, the first demonstrations in the United States took place, with the reporting of the America’s Cup international yacht races at New York.

Marconi sailed to the United States at the invitation of the New York Herald newspaper to cover the America’s Cup races off Sandy Hook, NJ. The transmission was done aboard the SS Ponce a passenger ship of the Porto Rico Line. According to the Proceedings of the United States Naval Institute by the United States Naval Institute, the Marconi instruments were tested around 1899 and the tests concerning his wireless system found that the „[…] coherer, principle of which was discovered some twenty years ago, [was] the only electrical instrument or device contained in the apparatus that is at all new”.

Transatlantic transmissions

Marconi watching associates raise kite antenna at St. John’s, December, 1901
“ See if you can hear anything, Mr. Kemp!

100th anniversary of Marconi’s transatlantic wireless transmission, commemorated on a 2001 British two pound coin.Around the turn of the century, Marconi began investigating the means to signal completely across the Atlantic, in order to compete with the transatlantic telegraph cables. Marconi soon made the announcement that on 12 December 1901, using a 152.4 m (500 foot) kite-supported antenna for reception, the message was received at Signal Hill in St John’s, Newfoundland (now part of Canada) signals transmitted by the company’s new high-power station at Poldhu, Cornwall. The distance between the two points was about 3,500 km (2,175 mi). Heralded as a great scientific advance, there was — and continues to be — some skepticism about this claim, partly because the signals had been heard faintly and sporadically. There was no independent confirmation of the reported reception, and the transmission, consisting of the Morse code letter S sent repeatedly were difficult to discern from atmospheric noise. (A detailed technical review of Marconi’s early transatlantic work appears in John S. Belrose’s work of 1995.)[16] The Poldhu transmitter was a two-stage circuit.[17][18] The first stage operated at lower voltage and provided the energy for the second stage to spark at a higher voltage. Nikola Tesla, a rival in transatlantic transmission, stated after being told of Marconi’s reported transmission that „Marconi [… was] using seventeen of my patents.”[19][20]

Feeling challenged by skeptics, Marconi prepared a better organized and documented test. In February, 1902, the SS Philadelphia sailed west from Great Britain with Marconi aboard, carefully recording signals sent daily from the Poldhu station. The test results produced coherer-tape reception up to 2,496 km (1,551 mi), and audio reception up to 3,378 km (2,099 mi). Interestingly, the maximum distances were achieved at night, and these tests were the first to show that for mediumwave and longwave transmissions, radio signals travel much farther at night than in the day. During the daytime, signals had only been received up to about 1,125 km (699 mi), less than half of the distance claimed earlier at Newfoundland, where the transmissions had also taken place during the day. Because of this, Marconi had not fully confirmed the Newfoundland claims, although he did prove that radio signals could be sent for hundreds of kilometres, despite some scientists’ belief they were essentially limited to line-of-sight distances.

On 17 December 1902, a transmission from the Marconi station in Glace Bay, Nova Scotia, Canada, became the first radio message to cross the Atlantic from North America. On 18 January 1903, a Marconi station built near Wellfleet, Massachusetts in 1901 sent a message of greetings from Theodore Roosevelt, the President of the United States, to King Edward VII of the United Kingdom, marking the first transatlantic radio transmission originating in the United States. However, consistent transatlantic signalling was difficult to establish.

Marconi began to build high-powered stations on both sides of the Atlantic to communicate with ships at sea, in competition with other inventors. In 1904 a commercial service was established to transmit nightly news summaries to subscribing ships, which could incorporate them into their on-board newspapers. A regular transatlantic radio-telegraph service was finally begun on 17 October 1907 between Clifden Ireland and Glace Bay, but even after this the company struggled for many years to provide reliable communication.

The two radio operators aboard the Titanic were not employed by the White Star Line but by the Marconi International Marine Communication Company. Following the sinking of the ocean liner, survivors were rescued by the Carpathia. When it docked in New York, Marconi went aboard with a reporter from the New York Times.[21] On 18 June 1912, Marconi gave evidence to the Court of Inquiry into the loss of the Titanic regarding the marine telegraphy’s functions and the procedures for emergencies at sea.

Patent disputes
Invention of radio and History of radio.
Marconi’s work built upon the discoveries of numerous other scientists and experimenters. His original „two-circuit” equipment, consisting of a spark-gap transmitter plus a coherer-receiver, was similar to those used by other experimenters, and in particular to that employed by Oliver Lodge in a series of widely reported demonstrations in 1894. There were claims that Marconi was able to signal for greater distances than anyone else when using the spark-gap and coherer combination, but these have been disputed (notably by Tesla).

In 1900 Alexander Stepanovich Popov stated to the Congress of Russian Electrical Engineers that: „[…] the emission and reception of signals by Marconi by means of electric oscillations [was] nothing new. In America, the famous engineer Nikola Tesla carried the same experiments in 1893.”[24]

The Fascist regime in Italy credited Marconi with the first improvised arrangement in the development of radio.[25] There was controversy whether his contribution was sufficient to deserve patent protection, or if his devices were too close to the original ones developed by Hertz, Popov, Branley, Tesla, and Lodge to be patentable.

While Marconi did pioneering demonstrations for the time, his equipment was limited by being essentially untuned, which greatly restricted the number of spark-gap radio transmitters which could operate simultaneously in a geographical area without causing mutually disruptive interference. (Continuous-wave transmitters were naturally more selective and less prone to this deficiency). Marconi addressed this defect with a patent application for a much more sophisticated „four-circuit” design, which featured two tuned-circuits at both the transmitting and receiving antennas. This was issued as British patent number 7,777 on 26 April 1900. However, this patent came after significant earlier work had been done on electrical tuning by Nikola Tesla. (As a defensive move, in 1911 the Marconi Company purchased the Lodge-Muirhead Syndicate, whose primary asset was Oliver Lodge’s 1897 tuning patent.) Thus, the „four-sevens” patent and its equivalents in other countries was the subject of numerous legal challenges, with rulings which varied by jurisdiction, from full validation of Marconi’s tuning patent to complete nullification.

In 1943, a lawsuit regarding Marconi’s numerous other radio patents was resolved in the United States. The court decision was based on the prior work conducted by others, including Nikola Tesla, Oliver Lodge, and John Stone Stone, from which some of Marconi patents (such as U.S. Patent 763,772 ) stemmed. The U. S. Supreme Court stated that,

The Tesla patent No. 645,576, applied for September 2, 1897 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. [… He] recognized that his apparatus could, without change, be used for wireless communication, which is dependent upon the transmission of electrical energy.[26]

In making their decision, the court noted,

Marconi’s reputation as the man who first achieved successful radio transmission rests on his original patent, which became reissue No. 11,913, and which is not here [320 U.S. 1, 38] in question. That reputation, however well-deserved, does not entitle him to a patent for every later improvement which he claims in the radio field. Patent cases, like others, must be decided not by weighing the reputations of the litigants, but by careful study of the merits of their respective contentions and proofs.”

The court also stated that,

It is well established that as between two inventors priority of invention will be awarded to the one who by satisfying proof can show that he first conceived of the invention.

The case was resolved in the U.S. Supreme Court by overturning most of Marconi’s patents. At the time, the United States Army was involved in a patent infringement lawsuit with Marconi’s company regarding radio, leading observers to posit that the government nullified Marconi’s other patents to render moot claims for compensation (as, it is speculated, the government’s initial reversal to grant Marconi the patent right in order to nullify any claims Tesla had for compensation). In contrast to the United States system, Mr. Justice Parker of the British High Court of Justice upheld Marconi’s „four-sevens” tuning patent. These proceedings made up only a part of a long series of legal struggles, as major corporations jostled for advantage in a new and important industry.

Continuing work
“ Have I done the world good, or have I added a menace? ”

Over the years, the Marconi companies gained a reputation for being technically conservative, in particular by continuing to use inefficient spark-transmitter technology, which could only be used for radiotelegraph operations, long after it was apparent that the future of radio communication lay with continuous-wave transmissions, which were more efficient and could be used for audio transmissions. Somewhat belatedly, the company did begin significant work with continuous-wave equipment beginning in 1915, after the introduction of the oscillating vacuum tube (valve). In 1920, employing a vacuum tube transmitter, the Chelmsford Marconi factory was the location for the first entertainment radio broadcasts in the United Kingdom—one of these featured Dame Nellie Melba. In 1922 regular entertainment broadcasts commenced from the Marconi Research Centre at Writtle.

Later years
“ His Excellency the Senator Marchese Guglielmo Marconi, president of the Royal Academy of Italy, Member of the Fascist Grand Council ”

In 1914 Marconi was made a Senator in the Italian Senate and appointed Honorary Knight Grand Cross of the Royal Victorian Order in the UK. During World War I, Italy joined the Allied side of the conflict, and Marconi was placed in charge of the Italian military’s radio service. In 1924, he was made a marchese by King Victor Emmanuel III.

Marconi joined the Italian Fascist party in 1923. In 1930, Italian dictator Benito Mussolini appointed him President of the Accademia d’Italia, which made Marconi a member of the Fascist Grand Council. Marconi was a participant in rallies that fostered fascist beliefs and composed fascist propaganda. Marconi also made speeches as an apologist for the actions of the fascist regime in Italy.

In 1935, Italian forces occupied the African nation of Ethiopia, resulting in near universal condemnation of Italy. Marconi made numerous radio speeches supporting the unprovoked attack, notorious enough that the BBC banned him from speaking on the subject. Marconi was pro-war in the era between the First and Second World War, and he was condemned for such beliefs by many.[29]

Marconi died in Rome in 1937 at age 63 following a series of heart attacks, and Italy held a state funeral for him. As a tribute, all radio stations throughout the world observed two minutes of silence. His remains are housed in the Villa Griffone at Sasso Marconi, Emilia-Romagna, which assumed that name in his honour in 1938.

Personal life and other facts
On 16 March 1905, Marconi married Beatrice O’Brien (1882-1976), daughter of Edward Donough O’Brien, 14th Baron Inchiquin, Ireland. They had three daughters (one of whom lived only a few weeks), and a son. They divorced in 1924 and the marriage was annulled in 1927.
On 15 June 1927, Marconi married Maria Cristina Bezzi-Scali (1900-1994) — they would have a single daughter.
Marconi’s children were Degna (1908-1998), Gioia (1916-1996), Giulio (1910-1971), and Elettra (born 1930).
Marconi had a brother, Alfonso, and a stepbrother, Luigi.
Premier Benito Mussolini was Marconi’s best man when he married his second wife in 1927.[30][31]
Marconi’s Italian military service consisted of serving in the Italian Army (commissioned 1914 as Lieutenant) and the Italian Navy (Commander).
The Bologna Airport (BLQ) is named after Guglielmo Marconi.
A Marconi memorial statue stands on Telegraph Hill in San Francisco.
A section of the town of Copiague, USA, was once named Marconiville after Guglielmo Marconi. On Great Neck Road there is an old gate which still reads „Marconiville”.
Marconi Stallions, a football club in Australia is named after Guglielmo Marconi.
Villa Marconi, a retirement home located in Nepean, Ontario is named after Marconi. The home has a large Italian population.
The Dutch radio academy bestows the Marconi Awards annually for outstanding radio programmes, presenters and stations.
La Scuola D’Italia, a private Italian school in New York’s Upper East Side, is named after Marconi.
Marconi Avenue, a street on The Hill, St. Louis is named after Marconi. The neighborhood has a large Italian population.
A commemorative British two pound coin was released in 2001 celebrating the 100th anniversary of Marconi’s first wireless communication.
In 1915 a friend of his, Mrs. Mary Cummins Brown of New York, perished in the sinking of the British luxury liner RMS Lusitania off the Irish coast, a fact he commented upon two days later in The New York Times

British Patents
British patent No. 12,039, Date of Application 2 June 1896; Complete Specification Left, 2 March 1897; Accepted, 2 July 1897 (later claimed by Oliver Lodge to contain his own ideas which he failed to patent)
US Patents
U.S. Patent 0,586,193  „Transmitting electrical signals”, (using Ruhmkorff coil and Morse code key) filed December 1896, patented July, 1897
U.S. Patent 0,624,516  „Apparatus employed in wireless telegraphy”.
U.S. Patent 0,627,650  „Apparatus employed in wireless telegraphy”.
U.S. Patent 0,647,007  „Apparatus employed in wireless telegraphy”.
U.S. Patent 0,647,008  „Apparatus employed in wireless telegraphy”.
U.S. Patent 0,647,009  „Apparatus employed in wireless telegraphy”.
U.S. Patent 0,650,109  „Apparatus employed in wireless telegraphy”.
U.S. Patent 0,650,110  „Apparatus employed in wireless telegraphy”.
U.S. Patent 0,668,315  „Receiver for electrical oscillations”.
U.S. Patent 0,760,463  „Wireless signaling system”.
U.S. Patent 0,792,528  „Wireless telegraphy”. Filed Oct 13, 1903; Issued 13, 1905.
U.S. Patent 0,676,332  „Apparatus for wireless telegraphy” (later practical version of system)
U.S. Patent 0,757,559  „Wireless telegraphy system”. Filed Nov 19, 1901; Issued Apr 19, 1904.
U.S. Patent 0,760,463  „Wireless signaling system”. Filed Sep 10, 1903; Issued May 24, 1904.
U.S. Patent 0,763,772  „Apparatus for wireless telegraphy” (Four tuned system; this innovation was predated by N. Tesla, O. Lodge, and J. S. Stone)
U.S. Patent 0,786,132  „Wireless telegraphy”. Filed Oct 13, 1903
U.S. Patent 0,792,528  „Wireless telegraphy”. Filed Oct 13, 1903; Issued Jun 13, 1905.
U.S. Patent 0,884,986  „Wireless telegraphy”. Filed Nov 28, 1902; Issued Apr 14, 1908.
U.S. Patent 0,884,987  „Wireless telegraphy”.
U.S. Patent 0,884,988  „Detecting electrical oscillations”. Filed Feb 2, 1903; Issued Apr 14, 1908.
U.S. Patent 0,884,989  „Wireless telegraphy”.
U.S. Patent 0,935,381  „Transmitting apparatus for wireless telegraphy”. Filed Apr 10, 1908; Issued Sep 28, 1909.
U.S. Patent 0,935,382  „Apparatus for wireless telegraphy”.
U.S. Patent 0,935,383  „Apparatus for wireless telegraphy”. Filed Apr 10, 1908; Issued Sep 28, 1909.
U.S. Patent 0,954,640  „Apparatus for wireless telegraphy”. Filed Mar 31, 1909; Issued Apr 12, 1910.
U.S. Patent 0,997,308  „Transmitting apparatus for wireless telegraphy”. Filed Jul 15, 1910; Issued Jul 11, 1911.
U.S. Patent 1,102,990  „Means for generating alternating electric currents”. Filed Jan 27, 1914; Issued Jul 7, 1914.
U.S. Patent 1,148,521  „Transmitter for wireless telegraphy”. Filed Jul 20, 1908.
U.S. Patent 1,226,099  „Transmitting apparatus for use in wireless telegraphy and telephony”. Filed Dec 31, 1913; Issued May 15, 1917.
U.S. Patent 1,271,190  „Wireless telegraph transmitter”.
U.S. Patent 1,377,722  „Electric accumulator”. Filed Mar 9, 1918
U.S. Patent 1,148,521  „Transmitter for wireless telegraphy”. Filed Jul 20, 1908; Issued Aug 3, 1915.
U.S. Patent 1,981,058  „Thermionic valve”. Filed Oct 14, 1926; Issued Nov 20, 1934.

See also
Invention of radio
List of people on stamps of Ireland
Jagdish Chandra Bose

^ a b „Guglielmo Marconi: The Nobel Prize in Physics 1909”
^ Physicsworld.com, „Guglielmo Marconi: radio star”, 2001
^ Robert McHenry, „Guglielmo Marconi,” in Encyclopaedia Britannica, 1993.
^ Williams, H. S., & Williams, E. H. (1910). Every-day science. New York: Goodhue Company. Page 54.
^ Marconi delineated his 1895 apparatus in his Nobel Award speech. See: Marconi, „Wireless Telegraphic Communication: Nobel Lecture, December 11, 1909.” Nobel Lectures. Physics 1901-1921. Amsterdam: Elsevier Publishing Company, 1967: 196-222. Page 198.
^ In the beginning of 1894, Nikola Tesla was transmitting to a distance of 50 miles from New York City to West Point. See the PBS website, „Marconi and Tesla: Who invented radio?” (ed. this is noted as having been accomplished in Leland’s book concerning Tesla’s „Work with Alternating Currents”)
^ Leland I. Anderson, Priority in the Invention of Radio — Tesla vs. Marconi, Antique Wireless Association monograph, 1980, examining the 1943 decision by the US Supreme Court holding the key Marconi patent invalid (9 pages). (21st Century Books)
^ This fact was known to many as, in 1893, Tesla stated in the widely known „On Light and Other High Frequency Phenomena” speech which was delivered before the Franklin Institute, Philadelphia, in February, and before the National Electric Light Association, St. Louis, in March, that „One of the terminals of the source would be connected to Earth [as a electric ground connection …] the other to an insulated body of large surface”.
^ Marconi did acknowledge this later in his Nobel Award speech. See: Marconi, „Wireless Telegraphic Communication: Nobel Lecture, December 11, 1909.” Nobel Lectures. Physics 1901-1921. Amsterdam: Elsevier Publishing Company, 1967: 196-222. Page 206.
^ Alfred Thomas Story, The Story of Wireless Telegraphy. 1904. Page 58.
^ John J. O’Neill, Prodigal Genius:The Life of Nikola Tesla. Ives Washburn, New York, 1944
^ BBC Wales, „Marconi’s Waves”
^ Helgesen, Henry N., “Wireless Goes to Sea: Marconi’s Radio and SS Ponce”, Sea History (no. Spring 2008): 122
^ United States Naval Institute, Proceedings of the United States Naval Institute. The Institute, 1899. Page 857.
^ Page, Walter Hines, and Arthur Wilson Page, The World’s Work. Doubleday, Page & Company, 1908. Page 9625
^ Fessenden and Marconi: Their Differing Technologies and Transatlantic Experiments During the First Decade of this Century
^ „Marconi and the History of Radio”.
^ John S. Belrose, „Fessenden and Marconi: Their Differing Technologies and Transatlantic Experiments During the First Decade of this Century”. International Conference on 100 Years of Radio — 5-7 September 1995.
^ Margaret Cheney, Tesla, Man Out of Time, New Jersey : Prentice-Hall, Inc., 1981
^ Margaret Cheney and Robert Uth, Tesla: Master of Lightning, Barnes&Noble, 1999.
^ John P. Eaton & Charles A. Haas Titanic – Triumph and Tragedy, A Chronicle in Words and Pictures. 1994
^ Court of Inquiry Loss of the S.S. Titanic 1912
^ Marconi’s late-1895 transmission of signals was for around a mile. This was small compared to Tesla’s early-1895 transmissions of up to 50 miles. For more see „Nikola Tesla On His Work with Alternating Currents and Their Application to Wireless Telegraphy, Telephony, and Transmission of Power”, Leland I. Anderson, Twenty First Century Books, 2002, pp. 26-27.
^ „The Guglielmo Marconi Case; Who is the True Inventor of Radio”.
^ Gianni Isola, „Italian radio: History and Historiography”; Special Issue: Italian Media Since World War II. Historical Journal of Film, Radio and Television, August, 1995
^ U.S. Supreme Court, „Marconi Wireless Telegraph co. of America v. United States”. 320 U.S. 1. Nos. 369, 373. Argued April 9-12, 1943. Decided June 21, 1943.
^ a b Wireless Telegraph co. of America v. United States.
^ William John Baker, „History Of The Marconi Company 1874-1965”. 1996. 416 pages. Page 296
^ EPN, „The Unseen Marconi”
^ George P. Oslin, The Story of Telecommunications. 1992. 507 pages. Page 294.

The Guglielmo Marconi Case Who is the True Inventor of Radio
U.S. Supreme Court, „Marconi Wireless Telegraph co. of America v. United States”. 320 U.S. 1. Nos. 369, 373. Argued April 9-12, 1943. Decided June 21, 1943.
21st Century Books: Priority in the Invention of Radio — Tesla vs. Marconi

For the complete inventors list please click here