Guglielmo Marconi

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”.

italy_1990_2000_lire_f_mm

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).

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. As a child Marconi didn’t 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.

italy_guglielmo_marconi

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 kilometres (2,100 miles). 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 transalantic transmission, stated after being told of Marconi’s reported transmission that “Marconi [... was] using seventeen of my patents.”

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 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.

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.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article “Guglielmo Marconi”