A SIGNAL CROSSES THE ATLANTIC


Newfoundland 1901. Launching the kite for supporting the receving Antenna.

Towards the end of 1901, Marconi set up a transmitting station at Poldhu', in Cornwall, on a peninsula jutting out into the Atlantic Ocean. The receiving station (where Marconi went himself) was built on the other side of the Ocean, on the North American* island of Newfoundland, the nearest to Europe. For three hours every day (from one to three o'clock a.m. and from twelve to one o'clock p.m.), Poldhu transmitted the telegraphic signal of the letter "S" while Marconi experimented with newer and larger types of antenna suspended from light kites. Finally, a little after midday on 12 December 1901, the signal arrived. For the first time ever, electromagnetic waves had crossed the Ocean, travelling a distance of 3,500 kilometres. Marconi and his contemporaries couldn't know it, but the success of their experiment was due to the presence of the ionosphere - whose existence was not known until it was discovered by the English physicist, Appleton, in 1924. The ionosphere plays a fundamental role in all radio communications because it is a layer of the upper atmosphere (at an altitude of between 60 and 500 kilometres) which retlects electromagnetic waves like a mirror and allows a radio signal to reach any part of waves like a mirror and allows a radio signal to reach any part of the earth after a series of reflections between it and the earth's surface.


Note: the item "American" refers to the continent named America by the writer Martin Waldseemuller in 1507, in remebrance of the famous Italian navigator Amerigo Vespucci. So "American island of Newfoundland" means there is an island named Newfoundland in a continent named America. North America is, obviously, a piece of the American continent.


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