IMPROVEMENTS IN SIGNAL INSTRUMENTS OR APPARATUS FOR MAKING OR TRANSMITTING ELECTRIC TELEGRAPHIC SIGNALS
Year: 1857

page_text: .application for Letters Patent was not given within the time prescribed
by the Act.)
PROVISIONAL SPECIFICATION left by Frederick Priestley at the Office.
of the Commissioners of Patents, with his Petition, on the 15th October.
1857.
I, FREDERICK PRIESTLEY, of Berners Street, Oxford Street, in the County of
Middlesex, Pianoforte Manufacturer, do hereby declare the nature of the
Invention for "IMPROVEMENTS IN SIGNAL INSTRUMENTS OR APPARATUS FOR MAKING
OR TRANSMITTING ELECTRIC TELEGRAPHIC SIGNALS," to be as follows:-
-
It is well known that in all or most of the principal systems of electric
telegraphs at present in use, in order to avoid the necessity of separate wires'
for each signal to be transmitted, the same wire is employed for transmitting
various signals by repeating the simple signal twice, three times, or oftener, as
also by reversing the current and varying the duration of, and period between;
the repetition of the simple signal. By these or other well-known means'
various compound signals are made in respect of and for several single or
simple letters of the alphabet, numerals, ciphers, or other symbols, the use of
one wire only, or the combinations resulting from the use of two or only a few
wires being sufficient for clearly and satisfactorily establishing, a complete
alphabet or code of signals, as may be required.. But in transmitting or
forming such compound signals with the instruments or apparatus ordinarily.
employed, it is necessary to make the two, three, or more simple signals of

page_text: which they are composed, by two, three, or more corresponding mechanical
efforts exerted or produced upon the handles, keys, or other manipulating
portions of the instruments. An exception to this practice, however, obtains
in the use of Bain's system, in which, although great rapidity is obtained in
the actual transmission or formation of the signals, time is necessarily lost in
previously specially punching the slips of card to be employed.
Now, my Invention offers the advantages of Bain's system (not in respect
of a continuous message, but) in respect of the several separate compound
signals which may require to be made, by simplifying the manipulation or
work to be performed by the operator in the transmission or formation of such
signals, and consists in constructing electric telegraphic signal instruments
with a series of handles, keys, or other manipulating portions for producing
various compound signals in such manner, that one mechanical effort of the
operator exerted upon any one of such handles, keys, or manipulating portions
shall transmit or form the several simple signals, of which the particular corre-
sponding compound signal is composed.
And in order to explain my Invention the more clearly, I append the
following illustrative example of its application. Under the usual system of
either the single needle or the double needle telegraph, a compound signal con-
sisting of three movements of one of the needles either to the right or left,
would require three corresponding mechanical movements to be given to the
handles of the instrument, for the purpose of three several times making and
breaking the electric circuit. But under my improved system the pressure
once only upon a single key will make and break the circuit as required, and
this action I effect in the manner shewn in the accompanying Sketch or
Drawing by the key a, causing the bent end of a piece of wire 6 to pass over
an alternately nonconducting and conducting surface c, d, the nonconducting
portions of the said surface being those marked c, and the conducting portions
those marked d. The latter are supposed to be rivetted or united to a plate e
at the back, in connection with the battery, and supposing the 'wire 6 to be
also in connection with the same, the action of the instrument is apparent."
A telegraphic signal instrument adapted for transmitting a complete
alphabet or code of signals will consist of a series of such keys and apparatus
as above described, but it is to be understood that into or amongst the said
series keys for transmitting or making simple signals (as heretofore practised)
may also be introduced.
The same description of instrument is also applicable to and may be used
in connection with the recording instruments employed under Morse's and
Bain's systems of electric telegraph.

page_text: To prevent misapprehension, I would here remark that my invention is in
some respects similar to the ordinary "step by step" or "dial" signal instru-
ments, by which different compound signals are transmitted or formed by
making and breaking contact, &c., a varying number of times, according to the
degree or amount to which the dial is turned round (or the wire moved round
over and upon the dial). Nevertheless my Invention possesses a distinct
feature of novelty as contrasted with such instruments, inasmuch as the latter
do not provide a separate or distinct movement in respect of each different
compound signal, but require the same movement in every case, varying only
in the extent or degree to which it is to be made.

page_text: LONDON: Printed by GEORGE EDWARD EYRE and WILLIAM SPOTTISWOODE.
Printers to the Queen's most Excellent Majesty. 1858.