communi- MENTS IN AND APPERTAINING TO TELEGRAPH ALARM APPARATUS
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by William Phillips Thompson at the
Office of the Commissioners of Patents on the 10th January 1878. A. com-
munication from abroad by Sigismund Mohr, of the City and Province of
Quebec, in the Dominion of Canada.
WILLIAM PHILLIPS THOMPSON, of 6, Lord Street, Liverpool, in the County of
" IMPROVE-
Lancaster, British and International Patent and Trade Mark Agent.
A communi-
MENTS IN AND APPERTAINING TO TELEGRAPH ALARM APPARATUS."
cation from abroad by Sigismund Mohr, of the City and Province of Quebec, in
the Dominion of Canada.
The first part of my Invention relates to the combination of an alarm bell or
Bounder, or its equivavent, with any fire, police, cab messenger, or other alarm box,
whether singly or wholly combined; the object of this part of my Invention is that
the person sending a message to the main office, may immediately ascertain by
response if said message has been duly and correctly received.
The second part of my Invention relates to the closing or cutting off of the box
from the main line for the time being, and this without affecting in any way, or
ringing the other bells, or any of them on the same circuit. At the same time the
electrical connection is maintained between the main office and all the other boxes,
which latter are in nowise affected by the transmission of a message to the box so
isolated.
A switch is arranged so that the current can pass through the electric bell or
through the contact maker, worked by clockwork, in such manner that a series of
breaks of contact are formed by the spring contact maker coming against notches
in a revolving wheel, the spacing apart of these notches being varied so as to give
the required signals. Or the switch can be arranged so as to continue the circuit
direct.
The alarm bell or sounder can be placed on the top of the box, or in any other
position to suit any other style or shape of box.
The switch or disconnector can be worked with a spring or moved by hand, dis-
connecting the box and signalling apparatus from the main line, and connecting the
bell with it; this connection is instantaneously established between the main office
7

page_text: and any box and bell or sounder on the main line, without interfering in any way
with the others. By this means the operator is enabled to assure himself of the
real'intent of the message by repeating it to the sender, thus avoiding the errors
which might be and often are made while the sender is under exceptional excite-
ment, and when entirely unwanted demands for services are signalled for such as
experience shows is frequently done.
The great defect in all existing district alarm telegraphs is that no means are
provided in any of them for enabling the sender of the message to be assured either
that his message has been correctly received at the main office, or even received
there at all. But the present Invention entirely overcomes this vital deficiency.
By its means communication is instantly effected at both ends, while the sender and
the receiver are equally assured that the message has been correctly and instan-
taneously transmitted and attended to.