MICHAEL FARADAY
discovered electro-magnetic induction between two entirely separate circuits.
Year 1837
The first patent for an
electric telegraph taken out by Cooke and Wheatstone (London) and by Morse
(U.S.A.)
Year 1838
K.A. Steinheil (Munich)
discovered the use of the earth return and suggested that remaining metallic
portion of the circuit might be dispensed with entirely, and a system of
wireless telegraphy established.
Year 1842
S.F.B. Morse made
wireless experiments by electric conduction trough a water across Washington
Canal and across wide rivers. Joseph Henry noticed that a single electric spark
about one inch long thrown into a circuit of wire in an upper room could
magnetise steel needles included parallel circuit of wire placed in a cellar
underground thirty feet below with two floors intervening. He was one of many
observers prior to Hertz who had noticed curious effects due to electric sparks
produced at a distance, which were commonly ascribed to ordinary electromagnetic
induction.
Year 1843
James Bowman Lindsay, of
Dundee, suggested that if it were possible to provide stations of not more than
twenty miles apart all the way across the Atlantic, there would be no need to
lay any cable.
Year 1845
Lindsay began making
experiments in 1845 across the river Tay, his method being to transmit messages
by means of electricity or magnetism trough and across the water without
submerged wires, the water being utilised as the conducting medium.
Year 1849
J.W. Wilkins revived the
same suggestion for wireless telegraphy, Dr. O'Shaughnessy (afterwards Sir
William O'Shaughnessy Brooke) succeded in passing intelligible signals without
any metallic conduction across the River Hoogly, 4200 ft. wide, in India, but
he found the cost of power prohibitive.
Year 1859
Bowman Lindsay gave a
demostration of his conduction system to the British Association Meeting, at
which Michael Faraday and Sir William Thompson (Lord Kelvin) were both present.
William H. Preece (afterwards Sir William) was deputed by the Electric
Telegraph Company to report on Lindsay's System.
Year 1862
John heyworth patented a
method of conveying electric signals without the invention of any continuous
artificial conductor. Cromwell Varley tried this method, but found it a
failure.
Year 1867
James Clerk Maxwell read
a paper before the Royal Society, in which he laid down the theory of
electro-magnetism, which he developed more fully in 1873, in his great treatise
on electricity and magnetism. He predicted the existence of the electric waves
that are now used in wireless telegraphy.
Year 1870
Von Bezold discovered
that oscillations set up by a condenser discharge in a conductor give rise to
interference phenomena.
Year 1872
Henry Highton made
various experiments across the River Thames with Morse's method.
Year 1879
David E. Huges
discovered the phenomena on which depends the action of coherers, which many
years late were used in early electric-wave signalling. He found that a tube of
metallic filings was sensitive to electric sparks made in its vicinity, and he
was able to obtain such effects on a tube connected to a battery and a
telephone at a distance of five hundreds yards.
Year 1880
John Trowbridge, of
Haward, systematically studied the problem of propagation of electric current
trough "earth" either soil or water, and he found that signalling
might be carried on over considerable distances by electric conduction trough
the earth or water between places not metallically connected.
Year 1882
Graham Bell experimented
with Trowbridge's method on the Potomac River, when signals were detected at a
distance of 1,5 miles. Sir William H. Preece made an experiment, using Morse's
method to connect the isle of Wight with the mainland across the Solent on two
occasions during the failure of the submarine cable in Solent.
Year 1883
Willoughby Smith, in a
paper before the Institution of Civil Enginners, London, suggested that
electric induction might be employed for railway signalling. Heinrich Rudolph
Hertz became privat docent at Kiel, where he began studies in Maxwell's
electro-magnetic theory. G.F. Fitzgerald suggested a method of producing
electromagnetic waves in space by the discharge of a condenser.
Year 1885
Thomas A. Edison, with
the assistance of Messrs. Gilliland, Phelps, and W. Smith, worked out a system
of communication between railway stations and moving trains by means of
induction and without the use of conducting wires. Sit. W.H. Preece made
experiments at Newcastle-on.Tyne which showed that in two completely insulated
circuits of square form, each side being 440 yards, placed a quarter mile
apart, telephonic speech was conveyed from one to the other by induction.
Year 1886
A. E. Dolbear of Tuft's
College, Boston, patented a plan for establishing wireless communication by
means of two insulated elevated plates, but there is no evidence that the
method proposed by him did, or could, effect the transmission of signals
between stations separated by any distance.
Year 1887
Heinrich Rudolph Hertz
discovered the progressive propagation of electro-magnetic action trough space,
and was able to measure the length and velocity of electro-magnetic waves and
to show that in transverse nature of their vibration and their susceptibility
to refraction and polarisation they are in complete accordance with the waves
of light and heat. Hertz employed as detector of the electric wave a simple
nearly closed circuit of wire, called "Hertz Resonator" but it is
subsequently discovered that the metallic microphone of Huges was a far more
sensitive detector. A.W. Heaviside established communication by telephoníc
speech between the surface of the erarth and the subterranean galleries of the
Broomhill Collieriers, 350 ft deep, by laying above and below the ground two
complete metallic circuits, each about 2,25 miles in length and parallel to
each other.
Year 1889
Elihu Thompson suggested
that electric waves were particulary suitable for the trasmission of signals
trough fogs and metal objects.
Year 1891
John Trowbridge
suggested that by means of magnetic induction between two separate and
completely insulated circuits communication could be effected between
distances.
Year 1892
Edouard Branly devised
an appliance for detecting electro-magnetic waves, which was known as a
"coherer". He discovered that these waves had the power of affecting
the electric conductivity of materials when in state of a powder. Sir. W.H.
Preece adopted a method which united both conduction and induction as the means
of affecting one circuit by the current in another. In this was he established
communication between two points on the Bristol Channel and at Lochness in
Scotland. C. A. Stevenson of Northern Lighthouse Board, Edinburgh, advocated
the use of an inductive system for communication between the mainland and
isolated lighthouses.
Year 1894
E. Rathenau of Berlin
experimented with a conductive system of wireless telegraphy and signalled
trough three miles of water.
Year 1895
Mr. G. Marconi's
investigations led him to the conclusion that Hertzian waves could be used for
telegraphing without wires, and he made important experiments at his father's
home in Italy. Willoughby Smith established communications by conduction with
the lighthouse on the Fastnet.
Year 1896
In February Mr. Marconi
come to england. His first experiments in this country were conducted at
Westbourne Park. On June 2nd Mr. Marconi lodged his application for the first
British Patent for Wireless Telegraphy, N° 12039 of 1896. In July of that year
he was introduced to Sir William H. Preece, the Chief Electrical Enginner of
the Post Office at whose request Mr. Marconi conducted experiments before the
officials of the Post Office, first over a distance of about 100 yards and
afterwards between the General Post Office and the Savings Bank Department in
Queen Victoria Street. Shortly aftewards a series of trials were conducted by
Mr. Marconi before Post Office officials and naval and military officers on
Salisbury Plain, when communication was successfully established over a
distance of 1,75 miles. On December 11th 1896, Sir William H. Preece delivered
a lecture at Toynbee Hall on "Telegraphy without Wires" Mr. Marconi
was present at this lecture and conducted experiments.
Year
1897
In March 1897, Mr.
Marconi gave a demostration on Salisbury Plain before the representatives of
various Government Departments, communicating being established over a distance
of 4 miles. In May further trials were made across the Bristol Channel between
Lavernock and Flatholm, a distance of over 3 miles: and the 13th of that month
communications was established between Lavernock Point and Brean Down , at a
distance of about 8 miles. Professor Slaby, a German scientist, was present at
these trials. In July Mr. Marconi was called to Italy by the Italian Minister
of Marine and gave demonstration of his invention in the Admirality buildings
at Rome, and before King Humbert at the Royal Palace of the Quirinale. Between
July 10th and 18th trials were made at Spezia at the request of Italian
Government and on the 17th and 18th communication was successfully made and
mantained between the Arsenal of San Bartolomeo at Spezia and the italian
cruiser San Martin at sea, at distances up to 16 km. On
July 20th 1897, the Wireless Telegraph and Signal Company, Limited, was
incorporated, with a capital of £ 100.000 to acquire Mr. Marconi's patents in
all countries except Italy and her dependancies. On August 27th, 1897, a
lecture was given by Professor Slaby at the Sailor's Home, Potsdam, on Wireless
Telegraphy, before the Emperor and Empress of Germany and the King of Spain. In
September and October further experiments were conducyed by Mr. Marconi on
Salisbury Plain for Post Office officials. Experiments were also carried out by
officials of the Post Office at Dover. Receiving apparatus was erected by a
Post Office official at Bath, and signals were received from Salisbury, 34
miles distant. In November the first Marconi Station was erected at the
Needles, Alum Bay, Isle of Wight. Experiments were conducted between that
Station and Madeira House, South Cliff, Bournemouth, where Mr. Marconi was
residing at the time, a distance of 14,5 miles. In December tests were made
between the Station of Alum Bay and a steamer, the height of the mast being
about 60 ft., and readable signals were obtained up to a distance of 18 miles,
Captain Kennedy, R.E., being present.
Year 1898
In May, 1898,
experiments were carried out by Mr. Marconi between St. Thomas's Hospital and
the House of Commons. In the same month experiments were carried out at the
request of Lloyd's between Ballycastle and Rathlin Island, a distance of 7,5
miles. On June 3rd Lord Kelvin visited the Needles Station and sent from there,
to his friend Sir Georges Stokes, the first paid Marconigram. On July 20th and
22nd the events of the Kingstown Regatta in Dublin were reported by wireless
telegraphy for the Dublin Daily Express from the steamer Flying
Huntress, equipped with the Marconi system. On August 3rd wireless
telegraphic communication was established between the Royal yacht Osborne
and Ladywood Cottage, Osborne, in order that Queen Victoria might communicate
with the Prince of Wales, then suffering from the results of an accident to his
knee. Constant and uninterrupted communications was mantained during the
sixteen days the system was in use. In September the installation at Madeira
House, Bournemouth, was removed to Poole harbour, Dorset. Under arrangement
with the Trinity House officials the utility and value of wireless telegraphy
as means of communication between lightships and the shore was demonstrated by
the installation in December,1898, of the East Goodwin Lightship and the South
Foreland Lighthouse. The intervening distance was 12 miles. Communications was
first established on Christmas Eve, and continuously mantained for more than a
year
Year 1899
During a gale in January
1899 a heavy sea struck the East Goodwin Lightship, carrying part of her
bulwarks away. The mishap was reported by wireless telegraphy to Trinity House.
On March 2nd Mr. Marconi read a paper on Wireless Telegraphy at the Institution
of Electrical Engineers. On March 3rd the S.S. R.F. Matthews ran into
the East Goodwin Lightship. The accident was reported by wireless telegraphy to
the South Foreland Lighthouse and lifeboats were promptly sent to the
assistance of the lightship. On March 27th communication was established across
the Straits of Dover between the Chalet d'Artois, Wimereux near Boulogne and
the South Foreland Lighthouse. During the naval manoeuvres in July three
British warships, the flagship Alexandra and the cruisers Europa
and Juno were equipped with Marconi apparatus and messages were
correctly exchanged between these vessels at distance up to 74 nautical miles
(about 85 land miles). In September Marconi Stations were installed at
Chelmsford and Dovercourt. During the meetings of British Association at Dover
and the Association Francaise pour l'Avancement de Science at Boulogne, in
August, communication between the two societies was mantained by means of
Marconi apparatus installed at Dover Town Hall and at Wimereux. The
international yacht races between the Shamrock and the Columbia
which took place in September and October 1899 were reported by wireless
telegraphy for the New York Herald. After the conclusion of the races,
series of trials were made at the request of the U.S.A. naval authorities
between the cruiser New York and the battleship Massachusetts,
signals being exchanged between the vessels at distances up to 36 miles. On the
return journey from America Mr. Marconi fitted the S.S. St. Paul with
his apparatus and on November 15th established communication with the Needles
Station when 36 miles distant. Reports of the progress of the war in South
Africa were telegraphed to the vessel and were published in a leaflet entitled
"The Transatlantic Times" printed on board the St. Paul. In
October 1899 the War Office adopted the Marconi apparatus for use in the field
in South Africa and on November 2nd six of the company electricians left for
South Africa with six sets of Marconi apparatus. The apparatus proved of
considerable service to the army and to the naval squadron in Delagoa Bay to
which several of the sets were subsequently transferred.
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