IMPROVED AUTOMATIC MEANS FOR. INDICATING THE PRESENCE OF FIRE IN BUILDINGS
Year: 1873

page_text: LETTERS PATENT to Percy Albert Blake, of Highbury, in the County
of Middlesex, for the Invention of "IMPROVED AUTOMATIC MEANS FOR.
INDICATING THE PRESENCE OF FIRE IN BUILDINGS."
Sealed the 17th October 1873, and dated the 19th April 1873.
PROVISIONAL SPECIFICATION left by the said Percy Albert Blake
at the Office of the Commissioners of Patents, with his Petition,.
on the 19th April 1873.
I, PERCY ALBERT BLAKE, of Highbury, in the County of Middlesex,
do hereby declare the nature of the said Invention for "IMPROVED
AUTOMATIC MEANS FOR INDICATING THE PRESENCE OF FIRE IN BUILDINGS," to be
as follows:
My Invention relates to a self-acting fire alarm by means of which'
the inmates of any house or building or persons in the neighbourhood
thereof may be warned of an outbreak of fire before it has attained any
considerable magnitude.

page_text: According to my Invention I employ fuses of various kinds in con-
nection with one or more maroons or other explosive, or with a bell or
alarum. The fuses are hung about the rooms of the house or about the
building in such manner that on a fire breaking out in any room or
part of the building the fuse will be quickly ignited and explode one or
more maroons consisting of cartridges of gun cotton or other explosive
(confined in a suitable case if necessary) with a sufficiently loud report
to alarm the inmates and warn them of the danger.
According to my Invention I employ fuses of various kinds in con-
nection with one or more maroons or other explosive, or with a bell or
alarum. The fuses are hung about the rooms of the house or about the
building in such manner that on a fire breaking out in any room or
part of the building the fuse will be quickly ignited and explode one or
more maroons consisting of cartridges of gun cotton or other explosive
(confined in a suitable case if necessary) with a sufficiently loud report
to alarm the inmates, and warn them of the danger.
If compressed gun cotton be employed it may be fired by means of
a detonating fuse, and therefore it need not be confined except for
protection.
By the explosion of two or more detonating charges in succession
two or more signals may be given, the first to awaken the inmates, and
the other or others to give warning of fire.
The fuse may either consist of a plain cord or strand of gun cotton in
which a thin wire may be introduced for its support, or the strand or
cord of gun cotton may be steeped in a semi-saturated boiling solution
of chlorate of potash, and enclosed in a paper casc pierced with small
holes at distances of about two to three feet.
The paper tubes are made in short lengths enlarged at one end to
receive the end of the adjacent length which is made to fit therein.
In applying the alarm to the different apartments of a house the
fuse would be hung around the several rooms, and communicate in the
manner hereafter described with one main fuse in connection with the
maroon or other detonating device or with a bell suitably disposed in or
about the building.
If a bell or alarum is employed it would be connected to a spring
held back by a cord of gun cotton, which on being ignited will release
the spring, and so sound the bell.
The connection between the branch fuses in the several rooms and.
the main fuse is made in such manner that although any one of the
branch fuses if ignited will fire the main fuse the latter will not ignite
the fuses in the other rooms. For this purpose the fuse leading from
any room is connected to the main fuse in the following manner :-
When the plain cord of gun cotton is used as the fuse in the room it is

page_text: necessary to attach it to a length of the cased fuse containing gun cotton
prepared as above described in order to carry it through the wall of the
room, and therefore the connection is the same whichever fuse be
employed. The paper case is made rather longer than the prepared gun
cotton within it at one end, and this end which is open is pierced across,
and attached by a piece of prepared gun cotton passed through the hole
to the main fuse. The fuse leading through the hole is constricted by a
ligature near the inner side of the wall to prevent the passage of
gases inwards to the room and the consequent ignition of the fuse
therein without preventing, the latter when ignited. from firing the
main fuse..
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Percy Albert Blake in the Great Seal Patent
Office on the 18th October 1873..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PERCY
ALBERT BLAKE, of Highbury, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Nineteenth day of April, in the ycar of
our Lord One thousand eight hundred and seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Percy Albert Blake, Her special licence
that I, the said Percy Albert Blake, my executors, administrators,
and assigns, or such others as I, the said Percy Albert Blake, my
exccutors, administrators, and 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
Ircland, the Channel Islands, and Isle of Man, an Invention for " IM-
PROVED AUTOMATIC MEANS FOR INDICATING THE PRESENCE OF FIRE IN BUILDINGS,"
upon the condition (amongst others) that I, the said Percy Albert Blake,
my executors or administrators, by an instrument in writing under my,
or their, or one of their hands and scals, should particularly describe
.
°

page_text: and ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Percy Albert Blake, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the Sheet of Drawings
hereunto annexed, and to the letters and figures marked thereon (that
is to say) :-
My Invention relates to a cheap and reliable self-acting fire alarm, by
means of which the inmates of any house or building or persons in the
neighbourhood thereof may be warned of an outbreak of fire before it
has attained any considerable magnitude.
According to my Invention I employ fuses of various kinds in con-
nection with one or more maroons or other explosive or with a bell or
alarum. The fuses are hung about the rooms of the house or about the
building in places where fire is to be apprehended (as, for instance, along
beams passing near flues or stove pipes) in such manner that on a fire
breaking out in any room or part of the building the fuses will be
quickly ignited, and simultaneously explode one or more moroons con-
sisting of cartridges of gun cotton or other explosive (confined in a
suitable case if necessary) with a sufficiently loud report to alarm the
inmates and warn them of the danger.
If compressed gun cotton or other substance capable of detonation be
employed it may be fired by means of a detonating fuse, and therefore
it need not be confined except for protection.
By the explosion of two or more detonating charges in succession two
or more signals may be given, the first to awaken the inmates, and the
other or others to give warning of fire. In extensive buildings the
precise locality of the fire may be indicated by the number of reports.
To produce the intervals between the reports each maroon would be
provided with a time fuse, the length of the several fuses being graduated
accordingly.
The fuse may either consist of a plain cord or strand of gun cotton
dyed any suitable color (in which a thin wire may be introduced for its

page_text: support), or the strand or cord of gun cotton may be steeped in a
semi-saturated boiling solution of chlorate of potash, and enclosed in
a paper case pierced with small holes at distances of about two to three
feet.
=
The paper tubes are made in short lengths enlarged at one end to
receive the end of the adjacent length which is made to fit therein, the
gun cotton being cut in similar lengths or made continuous.
It is,
however, preferably used in lengths, and should be stiffened by means of
starch or other stiffening to prevent the choking of the tube.
In applying the alarm to the different apartments of a house the fuse
would be hung around the several rooms, and communicate in the
manner hereafter described with one main fuse in connection with the
maroon or other detonating device, or with a bell suitably disposed in or
about the building.
If a bell alarum is employed the mechanism by which the alarum is
sounded would be retained by a detent or arm held by a cord of gun
cotton, which detent being liberated immediately the gun cotton is
ignited by the fuse to which it is connected will release the mechanism
and sound the alarum, or a common bell may be hung on a spring held
back or in tension by a rope of gun cotton, and released only when the
gun cotton is ignited.
The annexed Drawings illustrate the connections between the branch
and the main fuses.
Figure 1 shows the method of conveying the fuse through the wall of
a room, and the method of connecting the fuses from the several rooms
to one main fuse leading to the maroon or alarum, the connection being
such that though any one of the branch fuses if ignited will fire the
main fuse the latter will not ignite the fuses in the other rooms. When
one single line of fuse only is employed running through all the rooms
of a house the same connection is employed between the fuses in the
different rooms with the same object.
When a plain cord of gun cotton is used as the fuse in the room it is
necessary to attach it to a length of the cased fuse containing gun cotton
prepared as above described in order to carry it through the wall, as the
ordinary gun cotton is liable to be extinguished in passing through a
small passage.

page_text: a is the plain cord of gun cotton hung round the room, and b is a
paper case passed through an aperture in the wall, and containing a
strand d of gun cotton prepared with chlorate of potash, as before
mentioned.
For the sake of clearness I have indicated the ordinary gun cotton
fuse in brown lines, and the prepared cotton by red lines. The
cord d extends only partly through tube b, the inner extremity b¹ of
which is choked or constricted by a ligature. To ensure the passage of
the flame past this ligature the cord d is doubled one or more times at
this point. The other end of the tube b, which is open, is attached to
the main fuse e, which is a cord of ordinary gun cotton by a piccef of
the prepared gun cotton, which passes across the end of the tube b
through two apertures pierced therein. Thus it will be seen that there
is no connection between the piece f and the cord d within the tube
which stops short some inches from the end of the tube, so that although
the piece f, and consequently the main fuse e, will be fired by the
fuse a, d, yet should the main fuse e be ignited by the fuse of some other
room the flame will be unable to pass inwards through the tube and
ignite d, owing to the inner end of said tube being choked.
Figure 2 shows the connection between a cased branch fuse and a
cased main fuse. This is the same as before described. In this instance,
however, only the prepared gun cotton is used. The connecting link f
is threaded through holes pierced in the tube b, as before, and also
through the tube of the main fuse, as shown.
Having described the nature of my Invention, an the manner in s
which the same is to be performed, I declare that what I claim as my
Invention to be protected by the herein-before in part recited Letters
Patent is,―
1st. The improved fire alarm herein described consisting of a gun
cotton fuse, or system of fuses, applied to the walls or other parts of a
room or building, and connected with one or more maroons or other
detonating devices, or with a bell or mechanical alarum, substantially as
herein set forth.
2nd. The method of connecting a branch fuse to the main fuse or one
fuse to another, so as to prevent the passage of the flame in the one
direction, as, for instance, from the main to the branch fuse, whilst

page_text: admitting of it in the other direction, substantially as herein set forth
and represented in the Drawings.
3rd. The cased fuse consisting of a strand of gun cotton previously
prepared, as herein described, and passed through a paper tube or case
made in short lengths, and fitted together, as hercin set forth.
In witness whereof, I, the said Percy Albert Blake, have hereunto
set my hand and seal, this Fourteenth day of October, in the
year of our Lord One thousand eight hundred and seventy-
threc.