Guglielmo Marconi

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Guglielmo Marconi

Marconi.jpg
Guglielmo Marconi
Born

April 25, 1874
Palazzo Marescalchi, Bologna, Italy

Died July 20, 1937

Rome, Italy

Residence Flag of Italy Italy, Flag of United Kingdom United Kingdom
Nationality Flag of Italy Italian
Field Electrical engineer
Institutions Marconi Wireless Telegraph Co. Ltd.
Alma mater None
Known for Radio
Notable prizes Nobel.svg Nobel Prize in Physics (1909)
Religious stance Roman Catholic

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

Marconi's mastery of long-distance signal transmission by radio waves ahead of several competitors in the field owed much to his integration of selected technologies developed by his competitors into one system and his success in securing funding. He was involved in several patent disputes with his competitors, with some decisions in his favor and some against him.

Marconi's adult life had essentially two phases: The British period followed by the Italian period. Working from Britain starting in 1896 because he could secure funding there, Marconi proved his technology and established his company, the Wireless Telegraph & Signal Company (later Marconi's Wireless Telegraph Company). He also married an Irish woman in 1906 and together they would have four children.

The beginning of the shift to his Italian period may be marked by his service as director of the Italian military's radio service during World War I when Italy joined the United Kingdom and France on the Allied side of the conflict. Following the war, he joined the Fascists in 1923. He divorced his first wife in 1924, and married his second wife, an Italian, in 1927. The best man at their wedding was Benito Mussolini, who by then had assumed dictatorial powers. Until his death in 1937, Marconi remained a strong supporter of Fascism and Mussolini.


Contents

Birth and personal life

Marconi was born on April 25, 1874 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 Livorno. Baptized as a Catholic, he was brought up Protestant by his mother and was a member of the Anglican Church.

On March 16, 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 Degna (1908-1998) and Gioia (1916-1996)—and a son, Giulio (1910-1971). The couple divorced in 1924 and the marriage was annulled in 1927. Marconi remarried on June 15, 1927, to Maria Cristina Bezzi-Scali; Benito Mussolini was Marconi's best man.[1][2] The couple had a single daughter, Elettra (b. 1930). He formally converted to Catholicism after his second marriage.

Marconi's Italian military service consisted of serving in the Italian Army (commissioned 1914 as lieutenant) and the Italian Navy (commander).

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"—as 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.[3] Marconi's system had the following components:[4]

  • 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 meters. This was not the case for all researchers in the field of the wireless arts, though.[5][6]

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.[7] 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.[8] Soon he was able to transmit signals over the crest of a hill to a distance of approximately 1.5 kilometers (one 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, accompanied by his mother. 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 this time was 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.[9][10]

A series of demonstrations for the British government followed—by March 1897, Marconi had transmitted Morse code signals over a distance of about 6 kilometers (4 miles) across the Salisbury Plain, and on May 13, 1897, spanned the Bristol Channel from Lavernock Point, South Wales to Brean Down, a distance of 14 kilometers (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 December 11, 1896; and "Signalling through Space without Wires," given to the Royal Institute on June 4, 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 March 27, 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."[11]

Transatlantic transmissions

Marconi watching associates raise a 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 Ocean, in order to compete with the transatlantic telegraph cables. Marconi soon made the announcement that on December 12, 1901, using a 122-meter (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 kilometers (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.[12] The Poldhu transmitter was a two-stage circuit.[13][12] The first-stage possessed lower voltage and provided the energy for the second stage in resonance. Nikola Tesla, a rival in transatlantic transmission, stated after being told of Marconi's reported transmission that "Marconi [... was] using seventeen of my patents."[14][15]

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 kilometers (1,551 miles), and audio reception up to 3,378 kilometers (2,099 miles). Interestingly, the maximum distances were achieved at night, and thus these tests were the first to show that, for medium-wave and long-wave 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 kilometers (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 kilometers, 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 December 17, 1902, a transmission from the Marconi station in Glace Bay, Nova Scotia, became the first radio message to cross the Atlantic in an eastward direction. On January 18, 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 signaling 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 aboard the Titanic were not employed by 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.[16] On June 18, 1912, Marconi gave evidence to the court of inquiry into the loss of Titanic regarding the marine telegraphy's functions and the procedures for emergencies at sea.[17]

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.[18] There was controversy, though, whether his contributions 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 pioneer demonstrations for the time, his equipment was limited by being essentially untuned, which greatly restricted the number of spark-gap radio transmitters that 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 April 26, 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 United States Supreme Court. 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:

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.[19]

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.[19]

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. [19]

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 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. In 1923 he joined the fascists in Italy, and until his death, he was an apologist for the ruling regime. In 1924, Marconi was made a marchese by King Victor Emmanuel III. When dictator Benito Mussolini assumed power in Italy in 1922, 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. Marconi was anticipated, however, by Christian Hulsmeyer, who by 1904 had developed a radar system that operated on board ships to prevent collisions with other ships.

Marconi 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.


See also

Notes

  1. George P. Oslin (1992), The Story of Telecommunications, p. 294.
  2. Gerald Sussman (1997), Communication, Technology, and Politics in the Information Age, p. 90.
  3. H. S. Williams, and E. H. Williams (1910), Every-day Science (New York: Goodhue Company), p. 54.
  4. Marconi delineated his 1895 apparatus in his Nobel Award speech. Guglielmo Marconi - Nobel Lecture, Nobel Foundation. Retrieved July 9, 2007.
  5. In the beginning of 1895, Nikola Tesla was transmitting to a distance of 50 miles from New York City to West Point, New York. See the PBS website, "Marconi and Tesla: Who invented radio?"
  6. Leland I. Anderson, Priority in the Invention of Radio — Tesla vs. Marconi (Antique Wireless Association, 1980), examining the 1943 decision by the U.S. Supreme Court holding the key Marconi patent invalid (9 pages).
  7. 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.”
  8. Marconi did acknowledge this later in his Nobel Award speech. See Guglielmo Marconi - Nobel Lecture, Nobel Foundation. Retrieved July 9, 2007.
  9. Alfred Thomas Story (1904), The Story of Wireless Telegraphy. p. 58.
  10. John J. O'Neill, Prodigal Genius: The Life of Nikola Tesla (New York: Ives Washburn, 1944; Los Angeles: Angriff Press, 1973).
  11. United States Naval Institute (1899), Proceedings of the United States Naval Institute, p. 857.
  12. 12.0 12.1 John S. Belrose (1995), “Fessenden and Marconi: Their Differing Technologies and Transatlantic Experiments During the First Decade of this Century.” International Conference on 100 Years of Radio (September 5-7, 1995). Retrieved July 9, 2007.
  13. John S. Belrose, "Marconi and the History of Radio," IEEE Antennas and Propagation Magazine 46 (2) (April 2004): 130-131. Retrieved July 9, 2007.
  14. Margaret Cheney (1981), Tesla: Man Out of Time (New York: Touchstone, 2001, ISBN 0743215362).
  15. Margaret Cheney and Robert Uth, Tesla: Master of Lightning (New York: Barnes & Noble, 1999, ISBN 0760710058).
  16. John P. Eaton & Charles A. Haas (1994), Titanic - Triumph and Tragedy, A Chronicle in Words and Pictures.
  17. Court of Inquiry, Loss of the S.S. Titanic, 1912.
  18. Gianni Isola, “Italian radio: history and historiography,” Historical Journal of Film, Radio and Television (August 1995).
  19. 19.0 19.1 19.2 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. FindLaw. Retrieved July 9, 2007.

References

  • Alba, Rene (ed.). 1996. World Famous Scientists and Inventors. New York: FAR Publications.
  • Asimov, Isaac. 1982. Asimov's Biographical Encyclopedia of Science and Technology, 2nd ed. New York: Doubleday. ISBN 0385177712
  • Gillispie, Charles Coulston. 1975. Dictionary of Scientific Biography. New York: Scribner. ISBN 0684101211
  • Poincare, Lucien. 1909. The New Physics and Its Evolution. New York: D. Appleton and Co. ISBN 1426484690
  • Porter, Roy and Marilyn Ogilvie (eds.). 2000. The Biographical Dictionary of Scientists, 3rd ed. New York: Oxford University Press. ISBN 0195216636
  • Seitz, Frederick. 1996. “The Tangled Prelude to the Age of Silicon Electronics.” Proceedings of the American Philosophical Society 140: 291-300.

Further reading

  • Aitken, Hugh G. J. Syntony and Spark: The Origins of Radio. New York: John Wiley & Sons, 1976. ISBN 0471018163
  • Aitken, Hugh G. J. The Continuous Wave: Technology and American Radio, 1900-1932. Princeton, NJ: Princeton University Press, 1985. ISBN 0691083762
  • Garratt, G. R. M. The Early History of Radio: From Faraday to Marconi. London: Institution of Electrical Engineers, 1994. ISBN 085296-8450
  • Marconi, Degna. My Father, Marconi. James Lorimer & Co, 1982. ISBN 0919511147
  • Weightman, Gavin. Signor Marconi's Magic Box: The Most Remarkable Invention of the 19th Century and the Amateur Inventor Whose Genius Sparked a Revolution. Cambridge, MA: Da Capo Press, 2003. ISBN 0306812754

External links

All links retrieved July 9, 2007.

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