Guglielmo Marconi Works to Solve Directional Telegraphy, Testing His Wireless Invention For the First Time in the Real World (This letter contains a drawing of his telegraphy system in his hand)

Guglielmo Marconi

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"I propose using vertical reflectors the fittings of which I am having made here in London."?A remarkable letter both describing and illustrating a crucial invention in the history of global communicationThe principles of radio were not well understood before the theoretical work of Scottish physicist James Clerk Maxwell and the experimental work of the German physicist Heinrich Hertz. Maxwell?s electromagnetic theory, developed in the 1860?s, predicted the existence of electromagnetic waves; waves of an electrical nature that travelled through the air or empty space at the speed of light. In the 1880?s Hertz did a series of experiments to generate these waves and measure their properties. He produced sparks between two spherical electrodes with the aid of a high voltage induction coil, and the high frequency currents generated by these sparks flowed into two metal rods that Hertz connected to terminals. These currents in turn generated electromagnetic waves that radiated from the rods. Hertz then succeeded in developing an apparatus to detect the waves that he had generated. We now recognize that his radio wave generator and detector were a primitive form of radio transmitter and receiver. However, at the time, proof of the existence of Hertz?s faint waves did not seem especially significant and the utility of his experiments was unknown.By the end of 1895 Marconi had transmitted signals a distance of over a mile, and the next year he demonstrated his wireless telegraph apparatus to the Italian government (which showed little interest). Consequently he journeyed to England to try his luck there, forming a company to market his idea. The marine industry saw that radio could provide a way for ships to communicate beyond their lines of sight, and so became a customer. There was little demand for radio communications on land because its benefits were not yet understood; besides, telegraph networks were widespread and telephones were coming commonly into use.Enter the US military. In late 1899, Guglielmo Marconi was invited (and paid) by the New York Herald newspaper to use his fledgling wireless system to report on the progress of that year?s Americas Cup yacht races, which were to be held off the coast of New Jersey. He accepted, eager for any opportunity to promote his system. The U.S. Navy was very interested in the new technology and made arrangements to observe these operations, and conduct tests of their own. This Marconi successfully did. Still this was short distance work.But it confirmed for Marconi that radio communication had enormous potential, and moreover, gave him the insight on how to best demonstrate it; using high powered stations, he would send signals across the Atlantic Ocean! The idea that people could communicate wirelessly across the ocean was considered incredible if not impossible, but Marconi managed to convince his board of directors to authorize the experiment. One station was set up at Poldhu in Cornwall, England, and the second was slated for Newfoundland, Canada.In order to speed up the experiment he decided to take portable receiving equipment to Newfoundland initially rather than construct a permanent station. He and two assistants, Messrs. Kemp and Paget, sailed from Liverpool November 26, 1901 and arrived at St. John?s December 6. The true purpose of their trip to Newfoundland was kept secret; as far as the rest of the world was concerned, they were simply going to make tests for a future ship-shore station. But in mid December 1901, Marconi sent a signal, using fixed stations, across the Atlantic.Now he turned to another milestone: could he mount his stations to moving targets that could communicate across large expanses regardless of weather. Here he partnered with the LB&SCR (London, Brighton & South Coast Railway) which wasn?t just a railway. Like several British rail companies of the 19th?early 20th centuries, it also operated steamship services. Newhaven ? Dieppe was their most famous lin.

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Détails bibliographiques

• Titre: Guglielmo Marconi Works to Solve Directional Telegraphy, Testing His Wireless Invention For the First Time in the Real World (This letter contains a drawing of his telegraphy system in his hand)
• Reliure: Couverture souple
• Signé: Signé par l'auteur