IMPROVEMENTS IN APPARATUS FOR INDICATING FIRE OR INCREASE OF TEMPERATURE, WHICH APPARATUS 18 PARTLY APPLICABLE TO OTHER SIGNALLING PURPOSES
Year: 1874

page_text: ETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of
"IMPROVEMENTS IN APPARATUS FOR INDICATING FIRE OR INCREASE OF
TEMPERATURE, WHICH APPARATUS 18 PARTLY APPLICABLE TO OTHER SIGNALLING
PURPOSES." A communication from abroad by Charles Joseph
Baudry, of Paris, in the Republic of France, Railway Super-
intendent.
-
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition,
on the 19th November 1874.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the.
County of Middlesex, Gentleman, do hereby declaro the nature of the
said Invention for "IMPROVEMENTS IN APPARATUS FOR INDICATING FIRE OR
INCREASE OF TEMPERATURE, WHICH APPARATUS IS PARTLY APPLICABLE TO OTHER
SIGNALLING PURPOSES," a communication to me from abroad by Charles

page_text: the upper part of the tube closes the circuit, thereby causing the bell to
ring without cessation exactly as if a person were continuing to depress
the call knob or stud.
It is also proposed to construct apparatus of a similar description with
a second thermometrical tube, having connected thereto a special wire
communicating with an alarm bell, as also to employ a fire alarm,
constructed in the manner herein-before described, alone and without
being combined with the call or signalling bell used for domestic or
.similar purposes.
These apparatus may be constructed of such forms and dimensions as
to contribute to the decoration or ornamentation of the apartments or
places where they are required to be used.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 13th May 1875. .
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Nineteenth day of November, in the
year of our Lord One thousand eight hundred and seventy-four,
in the 38th year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said John Henry Johnson, Her
special license that I, the said John Henry Johnson, my executors,
administrators, and assigns, or such others as I, the said John Henry
Johnson, my executors, administrators, or assigns, should at any
time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN APPARATUS FOR INDICATING FIRE OR INCREASE
OF TEMPERATURE, WHICH APPARATUS IS PARTLY APPLICABLE TO OTHER SIGNALLING
PURPOSES," a communication to me from abroad by Charles Joseph

page_text: Secondly. A thermometric tube B (curved or rounded at each end)
enclosing a column of mercury C, and attached to a graduated plate F.
A platinum wire is inserted in the lower part in contact with the
mercury contained in the tube, whilst at the upper part of the tube
there is fixed a platinum wire D which enters to a distanco equivalent
to about 38 or 40 degrees centigrade, at which point a small reservoir is
formed for the purpose of maintaining the mercury in contact with the
wire without the liability of bursting the tube. The platinum wires
introduced into the tube at its two extremities are attached to the two
conducting wires E, E', of the electric bell which lead to the knob or
button A. This arrangement admits of the apparatus being employed for
the domestic and daily use of all kinds of establishments, whilst by being
combined with the alarum thermometer it becomes at the same time a
. means of preservation for families and protection for property in the
event of fire, as should a fire or an undue elevation of temperature
occur the column of mercury shown at Crises until it reaches the wire D
introduced at the upper part of the tube B when it causes the bell to
ring incessantly, the effect being similar to that which is produced by
the depression of the knob or button A.
In addition to the arrangements herein-before described, which aro
adapted for ordinary purposes, it is also proposed to construct apparatus of
a similar description with a second thermometric tube, to which a special
wire for the alarum bell would be attached; as also a simple thermo-
larum, that is to say, an alarum not combined with the bells destined
for domestic purposes.
These apparatus of utility and security, which are also intended to
contribute at the same time to the decoration of apartments and other
places, may be constructed of various sizes adapted to the requirements
of any style or ornamentation.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is,―
First. The application and use of a thermometric tube, operating in
connection with an electric bell or alarum, substantially as and for the

page_text: Drawing.
Second. The combination with an electric bell or alarum operated by
hand for ordinary signalling purposes of a thermometric tube, arranged
so as to sound the bell or alarum automatically by means of an undue
elevation of temperature, substantially as herein-before described. and
illustrated by the accompanying Drawing.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, the Thirteenth day of
May, One thousand eight hundred and seventy-five.