Wireless telegraphy
Wireless telegraphy is the practice of remote communication (see
telegraphy) without the wires involved in an
electrical telegraph.
Wireless innovations lead to the
development of radio.
As far back as
Faraday and
Hertz in the early
1800s, it was clear to some scientists that wireless communication was possible, and many people worked on developing many devices and improvements. For instance, in
1832,
James Bowman Lindsay gave a classroom demonstration of UHF hertzian wireless telegraphy to his students. By
1854 he was able to demonstrate transmission across the
Firth of Tay from
Dundee to Woodhaven (now part of Newport-on-Tay), a distance of two miles. Various wireless telegraphy devices started appearing in the
1860s. Later,
Thomas Alva Edison received ,
"Means for Transmitting Signals Electrically" (
1891).
In
St. Louis,
Missouri,
Nikola Tesla made the first public demonstration of a modern wireless system in
1893. Addressing the
Franklin Institute in
Philadelphia and the
National Electric Light Association, he described and demonstrated in detail the principles of wireless telegraphy and radio. The apparatus that he used contained all the elements that were incorporated into
radio systems before the development of the
vacuum tube.
Jozef Murgas, the
"Radio Priest", contributed a lot of his revolutionary work in the late
1890s and early
1900s to wireless telegraphy.
In November
1894, Sir
Jagdish Chandra Bose ignited gunpowder and rang a bell at a distance using electromagnetic waves, confirming that communication signals can be sent without using wires. The later derived system (which used several patents of Tesla's) that achieved widespread use was demonstrated by
Guglielmo Marconi in
1896. Marconi and Braun shared the
1909 Nobel Prize in physics for "contributions to the development of wireless telegraphy".
A few decades later in the
history of radio, the term
radio itself became more popular. Early radio could not transfer sounds, only
Morse code in the tones made by rotary spark gaps. Canadian-American scientist
Reginald Aubrey Fessenden was the first to wirelessly transmit a human voice (his own). The ultimate development of wireless telegraphy was
telex on radio. The most advanced form (
CCITT R.44) automated both routing and encoding of messages over short wave radio. Telex on radio was invented in the 1940s, and was for many years the only reliable way to reach many distant countries (See
telegraphy for more information).
* Hugh G. J. Aitken,
Syntony and Spark: the Origins of Radio, ISBN 0471018163.
http://home.frognet.net/~ejcov/lindsay3.html
