Guglielmo Marconi

For the inventor of radio, see the competing claims in history of radio and the invention of Radio

Guglielmo Marconi
Guglielmo Marconi
Born	April 25 1874 Palazzo Marescalchi, Bologna, Italy
Died	July 20 1937 Rome, Italy
Residence	Italy, UK
Nationality	Italian
Field	Electrical engineer
Institutions	Marconi Wireless Telegraph Co. Ltd.
Alma mater	None
Known for	Radio
Notable prizes	Nobel Prize for Physics (1909)
Religious stance	Roman Catholic

Guglielmo Marconi, Marchese, GCVO (April 25, 1874-July 20, 1937) was an Italian inventor, best known for his pioneering work in use of radio wave transmissions for communication. He shared the 1909 Nobel Prize in Physics with Karl Ferdinand Braun, "in recognition of their contributions to the development of wireless telegraphy."

Birth and 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, Florence and, later, in Livorno. Baptized as a Catholic, he was brought up Protestant by his mother and was a member of the Anglican Church. He formally converted to Catholicism after his second marriage.

Radio work

During his early years, Marconi had an interest in science and electricity. One of 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," that had been predicted by James Clerk Maxwell on theoretical grounds in 1864. 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 became to find a way to use radio waves to create a practical system of "wireless telegraphy"—i.e. the transmission of telegraph messages without the need for the connecting wires used by the electric telegraph. This was not a new idea—numerous investigators had been exploring various wireless telegraph technologies for over 50 years, but none had yet 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 technologies and unified and adapted them to his system. 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, which in turn was similar to what Hertz had used;
• A wire or capacity area placed at a height above the ground, or what would today be called an antenna;
• A coherer receiver, which was a modification of Edouard Branly's original device, with refinements by Oliver Lodge that made it more sensitive and reliable; it consisted of a tube filled with iron filings that "cohered" in the presence of radio waves.
• A telegraph key, used 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 transmitted Morse code dots-and-dashes onto a roll of paper tape.

Similar configurations using spark-gap transmitters plus coherer-receivers had been tried by other experimenters, 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.

At first, Marconi could only signal over limited distances. However, in the summer of 1895, he moved his experimentation outdoors. After increasing the length of the transmitting and receiving antennas, arranging them vertically, and positioning them so that they were allowed to touch the ground, the transmission range increased significantly. (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.) Soon he was able to transmit signals, over the crest of a hill, to a distance of approximately 1.5 kilometres (1 mile). By this point he concluded that, with additional funding and research, a device could become capable of spanning even greater distances, and thus would prove valuable both commercially and for military use.

Finding limited interest in his work in his native Italy, in early 1896, at the age of 21, Marconi traveled to London, England, accompanied by his mother. (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 possesses at this time is strikingly similar to that of the one in 1882 by A. E. Dolbear, of Tufts College, which used a spark coil generator and a carbon granular rectifier for reception. A series of demonstrations for the British government followed—by March, 1897, Marconi had transmitted Morse code signals over a distance of about 6 kilometres (4 miles) across the Salisbury Plain, and on 13 May 1897, spanned the Bristol Channel from Lavernock Point, South Wales to Brean Down, a distance of 14 kilometres (8.7 miles). 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 in May, 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. 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

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 122-metre (400-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 kilometres (2,100 miles). Although widely heralded as a great scientific advance, there was also some skepticism about this claim, in part because the signals had only been heard faintly and sporadically. In addition, there was no independent confirmation of the reported reception, and the transmission, which merely consisted of the three dots of the Morse code letter S sent repeatedly, came from a transmitter whose signals were difficult to differentiate from the noise made by atmospheric static discharges. (A detailed technical review of Marconi's early transatlantic work appears in John S. Belrose's work of 1995.) The Poldhu transmitter was a two-stage circuit. The first-stage possessed lower voltage and provided the energy for the second stage in resonance. Nikola Tesla, a rival in transalantic transmission, stated after being told of Marconi's reported transmission that "Marconi [... was] using seventeen of my patents."

Feeling challenged by skeptics, Marconi prepared a better organized and documented test. In February, 1902, the S.S. 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 kilometres (1,551 miles), and audio reception up to 3,378 kilometres (2,099 miles). Interestingly, the maximum distances were achieved at night, and thus these tests were the first to show that, for mediumwave and longwave transmissions, radio signals travel much farther at night than during the day. During the daytime, signals had only been received up to about 1,125 kilometres (700 miles), which was 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 successfully prove that radio signals could be sent for hundreds of kilometres, in spite of the fact that some scientists had believed they were essentially limited to line-of-sight distances. (Oliver Heaviside speculated in 1902 that radio waves could be guided by a combination of ground surface and an ionized conducting layer high in the atmosphere, now called the Heaviside layer, and thus travel around the globe.)

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 in an eastward direction. 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 turned out to be very difficult to establish.

Marconi hereabout began to build high-powered stations on both sides of the Atlantic Ocean, in order 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 ocean-going ships, which could incorporate them into their on-board newspapers. A regular transatlantic radiotelegraph service was finally announced in 1907, but even after this the company struggled for many years to provide reliable communication.

Titanic

The two radio operators on-board 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. 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

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 what had been utilized by many other experimenters, and in particular with that employed by Oliver Lodge in a series of widely reported demonstrations in 1894. Marconi's main claim for novelty was that through his work he had been able to signal for much greater distances than anyone else had achieved when using the spark-gap and coherer combination. The Fascist regime in Italy credited Marconi with the first improvised arrangement in the development of radio. There was controversy, though, whether his contribution were of a sufficient enough breakthrough to deserve patent protection, or if his devices were too close to the original ones developed by Hertz, Branley, Tesla, and Lodge to be patentable.

Moreover, 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 given geographical area without causing mutually disruptive interference. (Continuous-wave transmitters were naturally more selective, thus 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 were the subject of numerous legal challenges, with mixed 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 Supreme Court of the United States. The court decision was based on the proven prior work conducted by others, such as by Nikola Tesla, Oliver Lodge, and John Stone Stone, from which some of Marconi patents (such as U.S. Patent 763772 (PDF)) stemmed. The 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."

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 litigations, 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 various observers to posit that the government nullified Marconi's other patents in order to moot any 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 U.S. high court, 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

Over the years, the Marconi companies began to gain a reputation for being technically conservative, in particular by continuing to use relatively inefficient spark-transmitter technology, which could only be used for radiotelegraph operations, long after it was becoming apparent that the future of radio communication lay with continuous-wave transmissions, which were more efficient and could also be used to make audio transmissions. Somewhat belatedly, the company did begin to do 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 transmitted in the United Kingdom—one of these featured Dame Nellie Melba. In 1922, regular entertainment broadcasts commenced from the Marconi Research Centre at Writtle near Chelmsford. When the British Broadcasting Company was formed in 1922, the Marconi company was a prominent participant.

Later years and death

In 1914 Marconi was both made a Senatore in the Italian Senate, and appointed Honorary Knight Grand Cross of the Royal Victorian Order in the United Kingdom. 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. From 1923, when he joined the Fascists in Italy, and until his death, was an apologist for the ruling regime. In 1924, he was made a marchese by King Victor Emmanuel III. When dictator Benito Mussolini assumed power in Italy, Marconi became one of his ardent supporters.

In 1931 Marconi began pioneering the use of shorter wavelengths for radio transmission. He installed a short wave link between the Vatican and the Pope's summer home in 1932, and as early as 1935, began discussing the use of short-wave transmissions for radar, a technology for tracking objects he had proposed as early as 1922. He also developed systems for marine navigation using microwave beacons.

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, being notorious enough for the BBC to ban him from talking about the subject. Following his death in 1937 at age 63, Italy held a state funeral commemorating Marconi's life. As a tribute, many radio stations throughout the world observed two minutes of silence.

Personal life and other facts

Family

• On 16 March 1905, Marconi married Beatrice O'Brien (m. 1905, div. 1924, b. 1882, d. 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 (m. 1927, b. 1900, d. 1994) — they would have a single daughter.
• Marconi's children were Degna (1908-1998), Gioia (1916-1996), Giulio (1910-1971), and Elettra (b. 1930).
• Marconi had a brother Alfonso and a stepbrother Luigi.

Trivia

• Premier Benito Mussolini was Marconi's best man when he married his second wife in 1927.
• Marconi's Italian military service consisted of serving in the Italian Army (commissioned 1914 as Lt.) and the Italian Navy (Commander).
• A section of the town of Copiague, NY was once named Marconiville, after Guglielmo Marconi. On Great Neck Road in there is an old gate standing 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 retirement home has a large Italian population.
• The Dutch radio academy yearly hands out the Marconi Awards for outstanding radio programmes, presenters and stations.
• A road in Wall Township, NJ that runs along Marconi's Belmar Station (named Marconi Road) was named in his honor. At the end of the road stands the top section of one of his many transmitting towers with a plaque commemorating his achievements in radio communications.
• The Guglielmo Marconi Society exists in Sault Ste. Marie, Ontario. It is also referred to as the Marconi Club. The Electra also exists for the female members. It is located on Albert Street, in which once was considered to be James Town [Little Italy]in Sault Ste. Marie. There are annual banquettes and festivals. Some are exclusive members and others open to the general public. Also, located next door to the Club is the "New Marconi Restaurant."

Patents

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 0586193 (PDF) "Transmitting electrical signals," (using Ruhmkorff coil and Morse code key) filed December 1896, patented July, 1897
• U.S. Patent 0624516 (PDF) "Apparatus employed in wireless telegraphy."
• U.S. Patent 0627650 (PDF) "Apparatus employed in wireless telegraphy."
• U.S. Patent 0647007 (PDF) "Apparatus employed in wireless telegraphy."
• U.S. Patent 0647008 (PDF) "Apparatus employed in wireless telegraphy."
• U.S. Patent 0647009 (PDF) "Apparatus employed in wireless telegraphy."
• U.S. Patent 0650109 (PDF) "Apparatus employed in wireless telegraphy."
• U.S. Patent 0650110 (PDF) "Apparatus employed in wireless telegraphy."
• U.S. Patent 0668315 (PDF) "Receiver for electrical oscillations."
• U.S. Patent 0760463 (PDF) "Wireless signaling system."
• U.S. Patent 0792528 (PDF) "Wireless telegraphy." Filed Oct 13, 1903; Issued 13, 1905.
• U.S. Patent 0676332 (PDF) "Apparatus for wireless telegraphy" (later practical version of system)
• U.S. Patent 0757559 (PDF) "Wireless telegraphy system." Filed Nov 19, 1901; Issued Apr 19, 1904.
• U.S. Patent 0760463 (PDF) "Wireless signaling system." Filed Sep 10, 1903; Issued May 24, 1904.
• U.S. Patent 0763772 (PDF) "Apparatus for wireless telegraphy" (Four tuned system; this innovation was predated by N. Tesla, O. Lodge, and J. S. Stone)
• U.S. Patent 0786132 (PDF) "Wireless telegraphy." Filed Oct 13, 1903
• U.S. Patent 0792528 (PDF) "Wireless telegraphy." Filed Oct 13, 1903; Issued Jun 13, 1905.
• U.S. Patent 0884986 (PDF) "Wireless telegraphy." Filed Nov 28, 1902; Issued Apr 14, 1908.
• U.S. Patent 0884987 (PDF) "Wireless telegraphy."
• U.S. Patent 0884988 (PDF) "Detecting electrical oscillations." Filed Feb 2, 1903; Issued Apr 14, 1908.
• U.S. Patent 0884989 (PDF) "Wireless telegraphy."
• U.S. Patent 0935381 (PDF) "Transmitting apparatus for wireless telegraphy." Filed Apr 10, 1908; Issued Sep 28, 1909.
• U.S. Patent 0935382 (PDF) "Apparatus for wireless telegraphy."
• U.S. Patent 0935383 (PDF) "Apparatus for wireless telegraphy." Filed Apr 10, 1908; Issued Sep 28, 1909.
• U.S. Patent 0954640 (PDF) "Apparatus for wireless telegraphy." Filed Mar 31, 1909; Issued Apr 12, 1910.

• U.S. Patent 0997308 (PDF) "Transmitting apparatus for wireless telegraphy." Filed Jul 15, 1910; Issued Jul 11, 1911.
• U.S. Patent 1102990 (PDF) "Means for generating alternating electric currents." Filed Jan 27, 1914; Issued Jul 7, 1914.
• U.S. Patent 1148521 (PDF) "Transmitter for wireless telegraphy." Filed Jul 20, 1908.
• U.S. Patent 1226099 (PDF) "Transmitting apparatus for use in wireless telegraphy and telephony." Filed Dec 31, 1913; Issued May 15, 1917.
• U.S. Patent 1271190 (PDF) "Wireless telegraph transmitter."
• U.S. Patent 1377722 (PDF) "Electric accumulator." Filed Mar 9, 1918
• U.S. Patent 1148521 (PDF) "Transmitter for wireless telegraphy." Filed Jul 20, 1908; Issued Aug 3, 1915.
• U.S. Patent 1981058 (PDF) "Thermionic valve." Filed Oct 14, 1926; Issued Nov 20, 1934.

See also

• Jagdish Chandra Bose
• Radio
• Telegraph

Further reading

Relatives and company publications

• Marconi, Degna, My Father, Marconi, James Lorimer & Co, 1982. ISBN 0-919511-14-7
• Marconi's Wireless Telegraph Company, Year book of wireless telegraphy and telephony, London : Published for the Marconi Press Agency Ltd., by the St. Catherine Press / Wireless Press. LCCN 14017875 sn 86035439

Other

• Ahern, Steve (ed), Making Radio (2nd Edition) Allen & Unwin, Sydney, 2006.
• Aitken, Hugh G. J., Syntony and Spark: The Origins of Radio, New York: John Wiley & Sons, 1976. ISBN 0-471-01816-3
• Aitken, Hugh G. J., The Continuous Wave: Technology and American Radio, 1900-1932, Princeton, New Jersey: Princeton University Press, 1985. ISBN 0-691-08376-2.
• Anderson, Leland I., Priority in the Invention of Radio — Tesla vs. Marconi
• Baker, W. J., A History of the Marconi Company, 1970.
• Clark, Paddy, "Marconi's Irish Connections Recalled," published in "100 Years of Radio," IEE Conference Publication 411, 1995.
• Coe, Douglas and Kreigh Collins (ills), Marconi, pioneer of radio, New York, J. Messner, Inc., 1943. LCCN 43010048
• Garratt, G. R. M., The early history of radio: from Faraday to Marconi, London, Institution of Electrical Engineers in association with the Science Museum, History of technology series, 1994. ISBN 0-85296-845-0 LCCN gb 94011611
• Geddes, Keith, Guglielmo Marconi, 1874-1937, London : H.M.S.O., A Science Museum booklet, 1974. ISBN 0-11-290198-0 LCCN 75329825 (ed. Obtainable in the U.S.A. from Pendragon House Inc., Palo Alto, California.)
• Hancock, Harry Edgar, Wireless at sea; the first fifty years: A history of the progress and development of marine wireless communications written to commemorate the jubilee of the Marconi International Marine Communication Company, Limited, Chelmsford, Eng., Marconi International Marine Communication Co., 1950. LCCN 51040529 /L
• Janniello, Maria Grace, Monteleone, Franco and Paoloni, Giovanni (eds) (1996), One hundred years of radio: From Marconi to the future of the telecommunications. Catalogue of the extension, Venice: Marsilio.
• Jolly, W. P., Marconi, 1972.
• Kinzie, P. A., Early Wireless: Marconi was not Alone, azarc.org.
• Larson, Erik, Thunderstruck, New York: Crown Publishers, 2006. ISBN 1-4000-8066-5 A comparison of the lives of Hawley Harvey Crippen and Marconi. Crippen was a murderer whose Transatlantic escape was foiled by the new invention of shipboard radio. Marconi does not come off as a very pleasant character.
• Masini, Giancarlo, Guglielmo Marconi, Turin: Turinese typographical-publishing union, 1975. LCCN 77472455 (ed. Contains 32 tables outside of the text)
• Mason, H. B. (1908). Encyclopaedia of ships and shipping, Wireless Telegraphy. London: Shipping Encyclopaedia. 1908. 707 pages.
• Page, Walter Hines, and Arthur Wilson Page, The World's Work. Doubleday, Page & Company, 1908. Page 9625
• Stone, Ellery W., Elements of Radiotelegraphy
• Weightman, Gavin, Signor Marconi's magic box: the most remarkable invention of the 19th century & the amateur inventor whose genius sparked a revolution, 1st Da Capo Press ed., Cambridge, MA : Da Capo Press, 2003. ISBN 0-306-81275-4

External links

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General

• Canadian Heritage Minute featuring Marconi
• Guglielmo Marconi documentary narrated by Walter Cronkite
• Nobel Prize: Guglielmo Marconi biography
• Marconi Corporation's Marconi Calling
• Review of Signor Marconi's Magic Box
• Information about Marconi and his yacht Elettra
• Comitato Guglielmo Marconi International, Bologna, ITALY
• I diari di laboratorio di Guglielmo Marconi
• Marconi il 5 marzo 1896, presenta a Londra la prima richiesta provvisoria di brevetto, col numero 5028 e col titolo "Miglioramenti nella telegrafia e relativi apparati"
• Raccolta dei brevetti marconiani registrati in Gran Bretagna e Francia tra il 1896 e il 1924
• Sparks Telegraph Key Review An exhaustive listing of wireless telegraph key manufacturers including photos of most Marconi keys
• Cherished Television, Part one: The Pioneers
• Marconi Belmar station, InfoAge. (See also, Marconi Period of Significance Historic Buildings)
• Marconi on the 2000 Italian Lire banknote.
• Marconi's Use of Kites to Assist Wireless Communication [1]
• Marconi's Case File at The Franklin Institute with info about his 1918 Franklin Medal for application of radio waves to communications
• History of Marconi House

Transatlantic "signals"

• BBC Reference to his first transmission over water
• Faking the Waves, 1901

Priority of invention

vs Tesla

• PBS: Marconi and Tesla: Who invented radio?
• 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

vs Popov

• Who started the electronic era?

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