AN AUTOMATIC FIRE ALARM
Year: 1874

page_text: PROVISIONAL SPECIFICATION left by Henry Colo at the Office of the
Commissioners of Patents, with his Petition, on the 27th July
1874. A communication from abroad by Messrs. Klingelhoefer
& Co., of Rio de Janerio, Brazil.
I, HENRY COLE, of the Firm of Cole, Savill, & Co., 21, Billiter St.,
in the City of London, E.C., do hereby declaro the nature of the said
Invention for "AN AUTOMATIC FIRE ALARM," to be as follows :—
A, the alarm; B, the electric battery; C, non-graduated thermometer,
all conveniently connected by copper wire covered with an isolating
substance. The tube C, similar to a mercurial thermometer, is fixed to
the ceiling & supported by a small metallic box by a wire of iron or
platine S, S, which is extended in the inside of the tube to a point which
the column of mercury will reach under the influence of a temperature
of from 40" to 50" centigrade. The thermometer is perforated under-
neath at p, likewise by an iron or platine wire which ends in the
mercury deposit, & is fixed to the metallic case in any point. The
metallic box which supports the tube is fixed to the wire S, S, by two
small cylinders of an isolating substance such as rosin, gutta percha, &c.

page_text: In the inside of this metallic box there is a small metallic rod, teethed,
t, t, with the teeth turned upwards, which is likewise fixed to the wire
8, S. The alarm A & the electric battery B need not of any description.
Any galvanic pilo in working condition for eight months or upwards
may serve as battery; Minotto, Bunson, Marić, Davids, &c., are authors
of convenient piles. The thermometers, the number of which depends
upon the extension of the room, are fixed to the ceiling as mentioned.
For each room it will be sufficient to have but one metallic box. The
other thermometers are fixed to the ceiling by the wire which extends
itself into the inside of the tube. The two wires of the tube (top &
bottom wires) are fixed one on one of the poles of the battery, the other
on the knob b of the alarm. From the knob a another wire leads to the
other pole of the battery. If there are many thermometers the different
wires are connected with the only two wires, one issuing from the battery,
& the other from the alarm. These will serve as the general connector.
It is useless mentioning that the wires should run along the ceilings for
safety sake. The battery ought to be fixed in a cool place, but by no
means in the sleeping room. The alarm will be placed where most con-
venient to the inhabitant or owner. Once the whole apparatus is fixed
as soon as a fire takes place in the room where exists a thermometer,
the hot air rising will force the mercury column up; as soon as this
column reaches the top wire the electric current is established, & the
interested are advised by the alarm. Should it happen that in case of too
high a temperature the mercury volatilizes or the thermometer bursts,
then the rosin or gutta percha cylinders which support & isolate tho
metallic case will be melted, & consequently the metallic case will
drop, & the upper part of the case coming in connection with the
teethed rod t, t, will establish the current (both wires being then in
connection with the case), and tho alarm will continue to act.