[cr-india] Dec. 12, 1896: Marconi Demos Radio

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Dec. 12, 1896: Marconi Demos Radio

Dec. 12, 1901: Marconi Transmits Across Atlantic

Inventor Guglielmo Marconi took wireless telegraphy from across-the-room
demo to across-the-ocean success in just five years.

Dec. 12: Inventor Guglielmo Marconi amazes a London assemblage in 1896 with
a demonstration of wireless communication across a room. Five years later to
the date, Marconi sends the first signal across an ocean.

Marconi was the son of an Italian country gentleman and Irish whiskey
heiress Anne Jameson. He took an early interest in physics, especially
electricity. His neighbor in Bologna, physics professor Augusto Righi,
encouraged Marconi to study the work of Heinrich Hertz.

In the attic of his villa, Marconi replicated Hertz's experiments on
"Hertzian waves," detecting sparks in one circuit with another circuit a few
meters away. By 1895 the young man extended the range to 2 kilometers.

Marconi tried to interest the Italian Ministry of Posts and Telegraphs in
transmitting messages without wires, but the burocrati weren't buying. In
England, however, a maternal cousin introduced Marconi to William Henry
Preece, engineer-in-chief of the British post office.

Preece had studied as a graduate student under Michael Faraday and was
working with his own wireless devices as early as 1892. He arranged for a
demonstration of Marconi's advanced apparatus at Toynbee Hall, a center of
social reform in East London.

The post-office engineer advertised the event and invited the press. Press
is the operative word, because there were obviously no electronic media
yet.

Marconi tapped a telegraph key in one part of the room, and Preece walked
around with a receiver box. Every time Marconi hit the key, a bell rang.
Look, Ma: no wires!

Tickle me, Guglielmo. The crowd was impressed. Marconi was 22 years old.

Marconi received the world's first patent for a system of wireless
telegraphy. He founded what would become the Marconi Wireless Telegraph
Company in 1897 and opened the world's first radio factory at Chelmsford,
England, in 1898.

The young inventor kept working on improvements. He sent radio signals a
distance of 12 miles in 1897 and across the English Channel (21 miles) in
1899. The following year, he received the famous patent No. 7777 for "tuned
or syntonic telegraphy." The concept was fundamental: Use different
frequencies to allow simultaneous transmissions without interfering with one
another. The improved signal quality also increased the range of radio
transmission.

Still, there was the issue of the curvature of the Earth. Many people
believed that would limit radio to local use. Marconi set out to prove them
wrong.

And that he did. Assistants telegraphed a prearranged signal, the letter S
(three clicks in Morse Code), from Poldhu in Cornwall, southwestern England,
to Marconi at Signal Hill, St. John's, Newfoundland, at 4:30 a.m. GMT on
Dec. 12, 1901. (An attempt the previous night had failed when a windstorm
knocked down the antenna, which was held aloft by a balloon.)

By sending a signal more than 2,100 miles across the Atlantic, Marconi
convincingly demonstrated the practicality of worldwide wireless
communication. And in 1909, he shared the Nobel Prize for physics with Karl
Ferdinand Braun of Germany, whose modifications to Marconi's transmitters
made them strong enough to be practical.

Marconi predicted the advent of radar in a lecture to the American Institute
of Radio Engineers in 1922. His own research progressed from short-wave
radio to microwaves, and in 1932 he opened the world's first microwave
radiotelephone link. It connected Vatican City with the pope's summer palace
at Castel Gandolfo.

Marconi actively supported and then served in Benito Mussolini's Fascist
government of Italy. Mussolini rewarded him in 1929 with the noble title of
marchese, and when Marconi died in 1937, Mussolini gave him a state funeral.

http://www.wired.com/science/discoveries/news/2008/12/dayintech_1212
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