Heroes of the Telegraph | Page 6

from the army and became an
inventor. His name is associated with a method of steering balloons,
and a filter for supplying Bordeaux with water from the Garonne. But
neither of these plans appear to have been put in practice, and he died at
Angouleme, leaving his widow in extreme poverty.
Sommering, a distinguished Prussian anatomist, in 1809 brought out a
telegraph worked by a voltaic battery, and making signals by
decomposing water. Two years later it was greatly simplified by
Schweigger, of Halle; and there is reason to believe that but for the
discovery of electro-magnetism by Oersted, in 1824 the chemical
telegraph would have come into practical use.
In 1806, Ralph Wedgwood submitted a telegraph based on frictional
electricity to the Admiralty, but was told that the semaphore was
sufficient for the country. In a pamphlet he suggested the establishment
of a telegraph system with public offices in different centres. Francis
Ronalds, in 1816, brought a similar telegraph of his invention to the
notice of the Admiralty, and was politely informed that 'telegraphs of
any kind are now wholly unnecessary.'
In 1826-7, Harrison Gray Dyar, of New York, devised a telegraph in
which the spark was made to stain the signals on moist litmus paper by
decomposing nitric acid; but he had to abandon his experiments in
Long Island and fly the country, because of a writ which charged him
with a conspiracy for carrying on secret communication. In 1830
Hubert Recy published an account of a system of Teletatodydaxie, by
which the electric spark was to ignite alcohol and indicate the signals of
a code.
But spark or frictional electric telegraphs were destined to give way to
those actuated by the voltaic current, as the chemical mode of
signalling was superseded by the electro-magnet. In 1820 the separate
courses of electric and magnetic science were united by the connecting

discovery of Oersted, who found that a wire conveying a current had
the power of moving a compass-needle to one side or the other
according to the direction of the current.
La Place, the illustrious mathematician, at once saw that this fact could
be utilised as a telegraph, and Ampere, acting on his suggestion,
published a feasible plan. Before the year was out, Schweigger, of
Halle, multiplied the influence of the current on the needle by coiling
the wire about it. Ten years later, Ritchie improved on Ampere's
method, and exhibited a model at the Royal Institution, London. About
the same time, Baron Pawel Schilling, a Russian nobleman, still further
modified it, and the Emperor Nicholas decreed the erection of a line
from Cronstadt to St. Petersburg, with a cable in the Gulf of Finland
but Schilling died in 1837, and the project was never realised.
In 1833-5 Professors Gauss and Weber constructed a telegraph between
the physical cabinet and the Observatory of the University of Gottingen.
At first they used the voltaic pile, but abandoned it in favour of
Faraday's recent discovery that electricity could be generated in a wire
by the motion of a magnet. The magnetic key with which the message
was sent Produced by its action an electric current which, after
traversing the line, passed through a coil and deflected a suspended
magnet to the right or left, according to the direction of the current. A
mirror attached to the suspension magnified the movement of the
needle, and indicated the signals after the manner of the Thomson
mirror galvanometer. This telegraph, which was large and clumsy, was
nevertheless used not only for scientific, but for general
correspondence. Steinheil, of Munich, simplified it, and added an alarm
in the form of a bell.
In 1836, Steinheil also devised a recording telegraph, in which the
movable needles indicated the message by marking dots and dashes
with printer's ink on a ribbon of travelling paper, according to an
artificial code in which the fewest signs were given to the commonest
letters in the German language. With this apparatus the message was
registered at the rate of six words a minute. The early experimenters, as
we have seen, especially Salva, had utilised the ground as the return
part of the circuit; and Salva had proposed to use it on his telegraph,
but Steinheil was the first to demonstrate its practical value. In trying,
on the suggestion of Gauss, to employ the rails of the Nurenberg to

Furth railway as the conducting line for a telegraph in the year 1838, he
found they would not serve; but the failure led him to employ the earth
as the return half of the circuit.
In 1837, Professor Stratingh, of Groninque, Holland, devised a
telegraph in which the signals were made by electro-magnets actuating
the hammers of two gongs or bells of different tone; and M. Amyot
invented an automatic sending key in the