Everything about Marconi S Wireless Telegraph Company totally explained
Marchese Guglielmo Marconi [guʎ'ʎe:lmomar'ko:ni] (
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. 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"—for example the transmission of telegraph messages without connecting wires as used by the
electric telegraph. This wasn't 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. 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 wasn't the case for all researchers in the field of the wireless arts, though.
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. (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 a hill, a distance of approximately . 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. A series of demonstrations for the British government followed—by March, 1897, Marconi had transmitted Morse code signals over a distance of about 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 . The message read "Are you ready". . The receiving equipment was almost immediately relocated to
Brean Down Fort on the Devon coast, stretching the range to .
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's at all new".
Transatlantic transmissions
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 . 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.) The Poldhu transmitter was a two-stage circuit. 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."
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, and audio reception up to . 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, less than half of the distance claimed earlier at Newfoundland, where the transmissions had also taken place during the day. Because of this, Marconi hadn't 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.
Titanic
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. 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
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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."
The
Fascist regime in
Italy credited Marconi with the first improvised arrangement in the development of radio. 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 ) 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.
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 isn't here [320U.S. 1, 38] in question. That reputation, however well-deserved, doesn't 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."}}
