IMPROVEMENTS IN APPARATUS FOR TELEGRAPHING BY ELECTRICITY
Year: 1863

page_text: PROVISIONAL SPECIFICATION left by Richard Archibald Brooman at
the Office of the Commissioners of Patents, with his Petition, on the
15th July 1868. A communication from abroad by Woldemar Strou-
binsky, of St. Petersburg, Russia.
I, RICHARD ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of
London, Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN APPARATUS FOR TELEGRAPHING BY ELECTRICITY," to be
as follows:-
The object of this Invention is to transmit two telegraphic messages along
the-same line wire and in the same direction. I proceed to describe the
Invention as applied to a Morse telegraph, it is, however, applicable to other
telegraphs. The property possessed by positive and negative electric currents.
of acting upon different magnetic relays is made use of to obtain the double
transmission. I operate as follows:-The sending station contains besides the
two ordinary manipulators a revolving commutator, which, when the circuit
is closed, is capable of transmitting positive and negative currents alternately
at the rate of from 20 to 26 times a second. This commutator is put in com-
munication with the two manipulators; if one manipulator is closed, a positive
current passes; if the other is closed, a negative current passes; and if both
are closed, the two currents are passed alternately. The receiving station
contains two magnetic relays, through which the telegraphic wire passes, each of
them being put in communication with a Morse instrument, the two telegraphs
will work separately and give different messages. It will be noticed that
instead of receiving dashes for signals, series of dots will be received, the

page_text: intensity of which would diminish sensibly on the passage of the two currents.
I avoid this inconvenience by employing a double relay with three armatures,
and by making the local batteries act continuously, their circuits being closed
between the instruments by the relay armatures and their stops. The
instruments will thus commence to work with the breaking of the circuit at
the relay, and will continue to work as long as the armatures vibrate. The
third armature completes the work during the passage of the two currents.
With a similar arrangement complete lines may be received for signals. In
order to transmit the messages to succeeding stations it will suffice to use the
same commutator. The instruments well answer as usual for manipulators.
The Invention will be fully understood on reference to the accompanying

page_text: and afford the means for not changing the relay in such case. The two
armatures 6 and 6" should be attracted by the poles s and n¹, but the arma-
ture & should be placed in the centre of magnetic action, capable, however, of
passing it on both sides. The arrangement of the local batteries, the instru-
ments, and the relays is represented at Figure 6. The currents from the
two batteries i, i, pass through the instruments k, l, and beyond them to the
armatures of the relay . While the relay is at rest the current passes round
the instruments, but when one of the armatures 6, for example, commences
to move, the corresponding instrument ¼ gives a signal, which continues
without interruption as long as the armature 6 vibrates. The same takes
place with the instrument k¹ when the armature 6" vibrates. The armature b¹
remains at rest in both these cases with the change of the current it changes
its screw only, and the instruments are not affected, but when the two currents
pass alternately, this armature then commences to vibrate. It thus breaks
the flow of the local currents through the wire f. The armatures 6 and 6", by
vibrating incompletely, but alternately in this instance keep the current always
broken, which cannot pass from d to h. The two currents being thus unable
to pass through the relay, work the two instruments together.