Masters of Space - Morse, Thompson, Bell, Marconi, Carty | Page 8

required, but it
proved to be a fertile suggestion which was followed by many other
thinkers. One experimenter after another added an improvement or
devised a new application.
A French scientist devised a telegraph which it is suspected might have
been practical, but he kept his device secret, and, as Napoleon refused
to consider it, it never was put to a test. An Englishman devised a
frictional telegraph early in the last century and endeavored to interest

the Admiralty. He was told that the semaphore was all that was
required for communication. Another submitted a similar system to the
same authorities in 1816, and was told that "telegraphs of any kind are
now wholly unnecessary." An American inventor fared no better, for
one Harrison Gray Dyar, of New York, was compelled to abandon his
experiments on Long Island and flee because he was accused of
conspiracy to carry on secret communication, which sounded very like
witchcraft to our forefathers. His telegraph sent signals by having the
electric spark transmitted by the wire decompose nitric acid and so
record the signals on moist litmus paper. It seems altogether probable
that had not the discovery of electro-magnetism offered improved
facilities to those seeking a practical telegraph, this very chemical
telegraph might have been put to practical use.
In the early days of the nineteenth century the battery had come into
being, and thus a new source of electric current was available for the
experimenters. Coupled with this important discovery in its effect upon
the development of the telegraph was the discovery of
electro-magnetism. This was the work of Hans Christian Oersted, a
native of Denmark. He first noticed that a current flowing through a
wire would deflect a compass, and thus discovered the magnetic
properties of the electric current. A Frenchman named Ampère,
experimenting further, discovered that when the electric current is sent
through coils of wire the magnetism is increased.
The possibility of using the deflection of a magnetic needle by an
electric current passing through a wire as a means of conveying
intelligence was quickly grasped by those who were striving for a
telegraph. Experiments with spark and chemical telegraphs were
superseded by efforts with this new discovery. Ampère, acting upon the
suggestion of La Place, an eminent mathematician, published a plan for
a feasible telegraph. This was later improved upon by others, and it was
still early in the nineteenth century that a model telegraph was
exhibited in London.
About this time two professors at the University of Göttingen were
experimenting with telegraphy. They established an experimental line
between their laboratories, using at first a battery. Then Faraday
discovered that an electric current could be generated in a wire by the
motion of a magnet, thus laying the basis for the modern dynamo.

Professors Gauss and Weber, who were operating the telegraph line at
Göttingen, adapted this new discovery to their needs. They sent the
message by moving a magnetic key. A current was thus generated in
the line, and, passing over the wire and through a coil at the farther end,
moved a magnet suspended there. The magnet moved to the right or
left, depending on the direction of the current sent through the wire. A
tiny mirror was mounted on the receiving magnet to magnify its
movement and so render it more readily visible.
One Steinheil, of Munich, simplified it and added a call-bell. He also
devised a recording telegraph in which the moving needle at the
receiving station marked down its message in dots and dashes on a
ribbon of paper. He was the first to utilize the earth for the return circuit,
using a single wire for despatching the electric current used in signaling
and allowing it to return through the ground.
In 1837, the same year in which Wheatstone and Morse were busy
perfecting their telegraphs, as we shall see, Edward Davy exhibited a
needle telegraph in London. Davy also realized that the discoveries of
Arago could be used in improving the telegraph and making it practical.
Arago discovered that the current passing through a coil of wire served
to magnetize temporarily a piece of soft iron within it. It was this
principle upon which Morse was working at this time. Davy did not
carry his suggestions into effect, however. He emigrated to Australia,
and the interruption in his experiments left the field open for those who
were finally to bring the telegraph into usable form. Davy's greatest
contribution to telegraphy was the relay system by which very weak
currents could call into play strong currents from a local battery, and so
make the signals apparent at the receiving station.

IV
INVENTIONS OF SIR CHARLES WHEATSTONE
Wheatstone and His Enchanted Lyre--Wheatstone and Cooke--First
Electric Telegraph Line Installed--The Capture of the "Kwaker"--The
Automatic Transmitter.
Before we