GIVING FIRE ALARMS
Year: 1884

page_text: I, JOHNSTON STEPHEN, Journalist, residing at Seventeen Ann Street, Edinburgh,
do hereby declare the nature of my invention for GIVING FIRE ALARMS to be as
follows:-
At various places throughout a Town and its suburbs posts or mural boxes are
placed. To these posts or mural boxes is led a wire which is in electrical circuit
with each and all of these posts or mural boxes and with the central Station.
Within each post or mural box is an Instrument which in many respects resembles
a Needle Telegraphic Instrument. Instead however of the Ordinary Transmitting
handle the axle or arbor forming the commutator is connected to the axle of an
Instrument well known as Maëlzel's Metronome, or to an adaptation of such an
Instrument. It will be seen then that if the Metronome be set to beat any number
of os-cillations in the minute, the current will be commutated once for each extreme
of the os-cillation of the pendulum of the Metronome.
The oscillations of the pendulum of the Metronome will thus automatically work
the Transmitter of the Needle Instrument commutating the current in alternate
senses with each semi-oscillation. Thus if the Metronome be "set" to os-cillate
forty times in the minute the current will be commutated eighty times in the
minute.
At the central station the wire passes to a Needle Instrument thence to a series
of solenoids arranged so as to be in the circuit. The solenoids are arranged in
pairs cach pair being curved so as to form an arc of a circle of which a pendulum
rod forms, from its point of support upwards, a radius. A magnet is mounted on
the top of the pendulum rod curved and placed in such a fashion that it will be a
core passing into one or other of the solenoids forming the pair.
Now all the pairs of solenoids,-and they are equal in number to the posts or
mural boxes,-have pendulums, and whereas the pairs of solenoids are all the same,
the pendulums are all different. That is to say, each pendulum has a definite length,
and therefore a definite period of os-cillation: and this period of os-cillation corre-
sponds with the os-cillation period of the Metronome proper to each District.
"
Now should a fire occur in any district the Policeman or other responsible person
will go to the Post or Mural box nearest to him, he will then shift the "bob
of the Metronome to the District where the fire is, and set the Metronome rod
oscillating. Let it be supposed that the Fire is in B. District, but that the Police-
man in F. District has been the first to observe the fire; he shifts the bob from F.,—
its normal position,-to B., and starts the Metronome.

page_text: The Metronome will now beat B. Number of times, and it will therefore com-
mutate the current twice B. number of times. The solenoids at the Central Station
will therefore have alternate positive and negative currents passing round them.
By a law in Physics, well known as Ampère's Theorem, the magnet will be pulled
into one of the solenoids forming the pair and pushed out of the other solenoid for
a positive current, while the reverse effect will be produced for a negative current.―
These effects will be produced at each change of the current.
But by a well understood law in Physics only that pendulum whose period of
os-cillation is co-incident with the impulses so transmitted will take up periodic
swaying, so the Pendulum which has the period proper to a certain district will be
the only one that will take up periodic oscillation.
When it has attained sufficient amplitude it strikes against a latch which
falls and thereby closes a local circuit which rings a bell or in other way calls
attention.
What I effect then is that each District has a fire call box, that the Instrument
in such fire call box can send an alarm not only for its own but for any other
district. The Instrument in each fire-call box can be used as a Transmitter by
grasping the rod and deflecting it to one side or another in any combinations which
shall be afore determined and indicated on the door of the Fire box.
I propose also to connect Shops, Warehouses, Public and other important
Buildings with the detent of the Metronome in such a way that when any one of
the local circuits is closed either by a press button on the outbreak of fire during
the day, or by the closing of circuit brought about by the action of heat on a
Thermostat during the night, such current shall energize an electro magnet which
shall attract an armature connected with the detent.
Dated this Nineteenth day of February Eighteen hundred and eighty four.

page_text: I, JOHNSTON STEPHEN, Journalist, of 17 Ann Street, Edinburgh, in the County
of Midlothian, do hereby declare the nature of my invention for GIVING FIRE
ALARMS BY ELECTRIC CURRENT and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement :— ·
At various places throughout a Town and its suburbs posts or mural boxes are
placed. To these posts, or mural boxes is led a wire which is in electrical circuit
with each and all of these posts or mural boxes and with the central Station.―
Within each post or mural box is an instrument which in many respects resembles
a Needle Telegraphic Instrument. Instead however of the ordinary transmitting
handle the axle or arbour forming the commutator is connected to the axle of an
Instrument well known as Maëlzel's Metronome, or to an adaptation of such an
Instrument.
It will be seen then that if the Metronome be set to beat any number of
Oscillations in the minute, the current will be commutated once for each extreme of
the oscillation of the pendulum of the metronome.
The oscillations of the pendulum of the Metronome will thus automatically work
the Transmitter of the Needle Instrument commutating the current in alternate
senses with each semi-oscillation. Thus if the Metronome be "set" to oscillate forty
times in the minute the current will be commutated eighty times in the minute.
At the Central Station the wire passes to a Needle Instrument thence to a series
of solenoids arranged so as to be in the circuit.-The solenoids are arranged in pairs,
each pair being curved so as to form an arc of a circle of which a pendulum rod
forms, from its point of support upwards, a radius-A magnet is mounted on the
top of the pendulum rod curved and placed in such a fashion that it will be a core
passing into one or other of the solenoids forming the pair.-Now all the pairs of
solenoids, and they are equal in number to the posts or mural boxes, have pendulums,
and whereas the pairs of solenoids are all the same, the pendulums are all different.
That is to say, each pendulum has a definite length, and therefore a definite period
of oscillation, and this period of oscillation corresponds with the oscillation period
of the Metronome proper to each District. Now, should a fire occur in any district
the Policeman or other responsible person will go to the Post or mural box nearest
to him, he will then shift the "bob" of the Metronome to the District where the
fire is, and set the Metronome rod oscillating.-Let it be supposed that the fire is
in B district, but that the Policeman in F district has been the first to observe the
fire; he shifts the bob from F, its normal position, to B, and starts the Metronome..
The Metronome will now beat B number of times, and it will therefore commutate
the current twice B number of times.-The solenoids at the Central Station will
therefore have alternate positive and negative currents passing round them.-By a
law in Physics, well known as Ampère's Theorem, the magnet will be pulled into
one of the solenoids forming the pair and pushed out of the other solenoid for a
positive current, while the reverse effect will be produced for a negative current.―
These effects will be produced at each change of the current.
But by a well understood law in Physics only that pendulum whose period of
oscillation is co-incident with the impulses so transmitted will take up periodic
swaying, so the pendulum which has the period proper to a certain District will
be the only one that will take up periodic oscillation.
When it has attained sufficient amplitude it strikes against a latch which falls
and thereby closes a local circuit which rings a hell or in other way calls attention.-.
What I effect then is that each district has a fițe call box, that the instrument in

page_text: such fire call box can send an alarm not only for its own but for any other district.
The Instrument in each fire call box can be used as a Transmitter by grasping the
rod and deflecting it to one side or another in any combinations which shall be
afore determined and indicated on the door of the fire box.
I propose also to connect shops, warehouses, Public and other important buildings
with the detent of the Metronome in such a way that when any one of the local
circuits is closed either by a press button on the outbreak of fire during the day, or
by the closing of circuit brought about by the action of heat on a Thermostat
during the night, such current shall energize an electro-magnet which shall attract
an armature connected with the detent.
In order that my Invention may be most fully understood and readily carried
into effect, I will describe the drawings hereunto annexed:-
Figures 1, and 2, (Sheet 1.) are respectively a part front elevation and a transverse
vertical section of a Fire call or mural box constructed according to and constituting
a part of my present Invention.
Figures 3, and 4, are respectively similar views of a portion of a Fire call or
mural box provided with an arrangement for generating alternating currents of
electricity.
Figures 5, 6, and 7, are respectively a front elevation, a side elevation and a
horizontal section of an arrangement of mechanism constituting the "call" at the
Central Station.
Figure 8, (Sheet 2.) is a diagrammatic view representing the manner of
connecting in series, a number of mural boxes or other calling stations with the
Central Station.
4
τ'
At various places throughout a town and its suburbs posts or mural boxes (such
as represented at Figures 1, and 2,) are situated.-To these posts or mural boxes is
led a wire which is in Electrical circuit with each and all of these posts or mural
boxes and with the Central Station.-Within each post or mural box is provided
an instrument which in many respects resembles a Needle telegraphic instrument.
The dial a, of this instrument is mounted in the box or case b, preferably formed
in part with the enclosing body c, of the post or mural box. The coil for the
operation of the needle indicator c¹, is connected by the wire d, to the binding
screw e. This binding screw e, with the binding screw f, at the opposite side of
the enclosing body c, (and hereinafter more particularly referred to) form the two
terminals of the post or mural box, by means of which the said post or mural box
may be placed in a circuit.-The wire g, is connected from the opposite side of the
needle instrument, to the binding screw h, which is in electrical connection with a
spring provided with the two free ends i, and j.-The tendency of the upper end j,
of this spring is always to bear in one direction against the metal bridge k, upon
whose opposite side the upper end j, of a similar spring bears in an opposite
direction. This last mentioned spring is in electrical connection with the binding
screw, which, by the wire m, is electrically connected to the binding screw f.-
The arrangement of mechanism hereinbefore described, constitutes the means
whereby currents, generated by, and conducted from a battery or other source of
electricity, outside or apart from the post or mural box shown at Figures 1, and 2,
are conducted between the terminals e, and f, of the said post or box.―The
terminals of the battery o, located within the post or mural box, are connected by
the wires p, to the binding screws q.-These binding screws q, are metallically
connected with the springs r, which bear upon the two metallic portions of the
commutator 8. These two metallic portions are insulated from each other but are
each in metallic contact with one of the pins t, which are situate between, but not
in contact with, the upper and lower ends j, and 2, of the springs hereinbefore
described. The commutator 8, constituting the means for commutating currents of
electricity to and through the coil operating the needle indicator c¹, as also to and
through all the similar coils in the series, is mounted rigidly upon the axle u, of an
Instrument well known as Maëlzel's Metronome, or to an adaptation of such an
instrument.—The mechanism for operating this instrument constituting no part of

page_text: my present Invention, I have represented as contained within the box v, secured
to the back of the post or mural box or in other convenient position.-The
metronome rod w, is carried upwards in front of the indicating plates a, and is
provided with the bob y, which is capable of being adjusted upon the same.-The
metronome rod w, is held norinally in position by means of the detent z, shewn
more particularly in side elevation at Figure 2.-This detent is hinged at a¹, and
may therefore be lowered by hand, thereby leaving the metronome rod free to
oscillate; or the detent z, may be released electrically by means of the electro-
magnet b', which, when the circuit is closed around the same, attracts the
armature c¹, secured to the lever d―This lever d¹, is pivoted to the bracket e¹,
supporting the electro-magnet b¹, and it is so weighted at i¹, as to retain the
detente, after having released the metronome rod w, in a neutral position.-One of
the terminals of the coil of the electro-magnet b¹, is metallically connected through
the wire f¹, with the binding screw g', the other terminal being metallically
connected to the several binding screws h', through the metal plate upon which
they are mounted.-In place of employing the several binding screws h¹, I may
provide one terminal to which I may connect any number of electrical Conductors.
It will be seen that if the circuit be closed around the electro magnet b', it will
attract the armature c¹, and thereby draw back the detent z, which thus left free
of support falls downwards from its hinge a¹, and thereby is maintained with the
assistance of the weight 2, in such position as will not interfere with the metronome
rod in its oscillation from one side to another.
In place of using a local battery o, and commutator 8, (hereinbefore described
with reference to Figures 1, and 2,) respectively for generating and alternating the
currents of electricity, I may employ the mechanism represented at Figures 3,
and 4, for generating currents of alternating senses.-This mechanism consists of
the core and bobbin ¹, which is suspended from, and below the axle u, of the
metronome, in such manner that for every oscillation of the metronome, the said
core and bobbin j¹, passes between the poles of permanent magnets, or preferably
a horse-shoe magnet as shewn at k³, and thereby sets up in the magneto-electric
coil currents of alternating senses.-The terminals of the coil are electrically
connected by the wires n, to the two insulated plates of the commutator U, with
which the springs m', are in continual electrical contact.-These springs are
metallically connected to the binding screws n', with which the wires g, and m,
(see also Figures 1, and 2,) are electrically connected.-Electrical currents passing
from any outside source through the wires g, or m, are conducted from one to the
other by means of the metallic connections o³, with the brackets p¹, to which are
secured the springs q¹, bearing upon, and in electric contact with the metal
bridge k.
It will be seen with reference to Figures 1, and 2, upon the deflection of the
metronome rod w, from one side to another, that the pins t, constituting the
terminals of the battery o, are alternately brought into contact with the free
ends i, and j, of the springs arranged at the sides thereof.-One of the upper free
ends, is also pressed back, by the upper pin t, out of contact with the bridge k,
and by this operation a current of electricity of one sense is conducted through the
uplifted spring, along the line of which it constitutes for the moment a terminal,
while a current of electricity of the opposite sense is conducted through the line of
which the opposite spring forms a terminal.
With reference to Figures 3, and 4, it is seen that upon the deflection of the
metronome rod w, from one side to another, the springs q', are alternately pressed
back out of contact with the bridge k, by means of the non-conducting pin r², and
that the alternating currents generated in the core and bobbin 7, are conducted
into and through the line by means of the bearing springs m¹, which for the
moment constitute the two terminals of the said line.
It will be seen from the mechanism hereinbefore described with reference to
Figures 1, to 4; (inclusive) that if the metronome, by means of the adjustable
bob Yi be Bet to beat any number of oscillations in the minute, the current of
"

page_text: electricity will be commutated once for each extreme of the oscillation of the
pendulum of the metronome.
The oscillations of the pendulum of the metronome will thus automatically work
the transmitters of the needle instruments which are constituted by the.com-
mutators 8, and 1', thereby commutating the current in alternating senses with
each semi-oscillation. Thus, if the Metronome be set to oscillate forty times in the
minute, the current will be commutated eighty times in the minute.
At the Central Station, the wire connected with the several posts or mural boxes,
is connected to a needle instrument and thence to a series of solenoids a¹, as repre-
sented at Figures 5 and 6, arranged so as to be in pairs, each pair being curved so
as to form an arc of a circle, of which, its pendulum rod t¹, forms from its point u²,
of suspension upwards, a radius.-A magnet v¹, carried at the upper end of the
pendulum rod t¹, is curved and mounted in such a manner that it is capable of
passing as a core into or out of one or other of the solenoids 81, forming the pair.-
These several solenoids s¹, and their respective connections, may be mounted upon,
base boards or supports apart from each other, but I prefer to mount them in series
upon one board or support w', as shewn at Figures 5, 6, and 7, of the annexed
drawings. The solenoids 8, are supported in the brackets a¹, which are secured
to the base board w¹, by screws or by other equivalent means. The series of
pendulums, I also mount upon the same point u¹, of suspension which, in its
continuity forms a rod, secured to the base board w', in any convenient manner,
and supported at its outer end in the bracket y¹, or its equivalent.-Now, all the
pairs of solenoids 81, and they are equal in number to the posts or mural boxes
arranged in the series, have pendulums z¹, and whereas the pairs of solenoids 8¹, are
all similar, the pendulums of the several pairs, have each a different and definite
period of oscillation.-The pendulum rods t¹, I prefer to form all of one length, the
several pendulum weights z¹, being adjusted thereupon in accordance with the
period of oscillation proper to itself. Below this arrangement of pendulums,
I arrange a series of automatic switches which are operated when the pendulums
have attained sufficient amplitude.-These switches are constructed with the
levers a³, which are pivoted at 62, the rod forming the continuous pivot of the
series of levers a³, being secured to the base-board or support w'.-Upon one end
of these levers there are or may be provided the rollers c², arranged with their axes
on a line parallel to that of the pivoted levers a²-The opposite ends of these
levers a, are provided with the hooks or catches d³, which normally engage with,
and support, the pivoted fall-contacts e-The continuous pivot f, of, and which is
in electrical connection with all of, these fall-contacts e², is secured to the base-
board or support w¹, and is electrically connected through the wire g³, with the
binding-screw 3-Upon the back of each of the fall-contacts e, when in a normal
position a spring h³, presses, and is in electrical contact therewith.-This series of
springs h, is secured to the metal bracket 2, which, through the wire *, is in
electrical connection with one terminal of the series of solenoids 8¹.-These
solenoids 8¹, it must be understood, are throughout electrically connected in series,
the other or opposite terminal of the series of solenoids s¹, being, by the conductor **,
in electrical connection with the binding-screw 13.-The series of contact pieces m³,
I prefer to arrange upon the board n³, a wire o³, leading from each of the said
contact pieces m³, to one of the binding screws p³.
It will be seen, from this arrangement of mechanism, that upon any one of the
pendulums attaining sufficient amplitude, the end of its pendulum rod t', impinges
upon its corresponding roller c, and causes it to descend, when, by the raising of
the opposite end of the lever a³, its corresponding fall-contact e³, makes electrical
connection through its contact piece m², with its corresponding binding screw p³.
At the Central Station, it is seen that the solenoids 81, by their line connection
with the posts or mural boxes, and upon the operation of any of the transmitting
apparatus within the same, have alternately positive and negative currents passing
round them. By a law in Physics, well known as Ampère's Theorem, one of a pair
of these solenoids will draw in and the other one expel the magnet for a positive

page_text: current, while the reverse effect will be produced for a negative current.-These
effects will therefore be produced at each change of the current, but, by a well
understood law in Physics, only that pendulum, whose period of oscillation is
coincident with the impulses so transmitted, will take up periodic swaying.-For
each district connected with the Central Station, there is arranged a certain period
of oscillation, and for each of these districts there is provided at the Central
Station, a pendulum 1, whose period of oscillation is coincident therewith.-The
pendulum therefore, which has the period proper to a certain district, is the only.
one which will take up periodic oscillation unisonant with the impulses passed.
around the solenoids 8¹.
The instrument in each post or mural box can be used as a transmitter, by
grasping and deflecting the metronome rod w, to one side or another in any
combinations which shall have been afore-determined, and as may be indicated
on the door of the said post or mural box.
Figure 8, shews in diagrain the method of connecting a series of fire call stations
with a Central Station. It is seen that the line wire 2, connected to the binding
screws e, and f, (Figures 1, and 2,) of the several posts or mural boxes, is led
to earth at one end, while the other is connected at the Central Station to the
Needle instrument A.-The line is then connected by the binding screw h³,
(Figures 5, 6, and 7) to the series of solenoids 8¹, and from the biuding screw 12,
the line is led to earth.-The series of binding screws p³, are each electrically
connected with one of the indicators of the group C, electrical connection being
made from these through the electro-magnetic coils of the bell D, to earth.-To the
post or mural box represented as of "Cheapside" I have shewn the method of
connecting a number of premises, such for example as, Shops, Warehouses, Public
and other buildings, with the electro-magnet 61, of the detent 2, of that post
or mural box. At each of these premises there is provided a battery F, one
terminal of which is led to earth, the other being connected with a press button G,
and with a thermostat K, the wire H, from each of which is electrically connected
to one of the binding screws h¹, (Figures 1, and 2,) an electrical connection being
made from the binding screw g¹, to earth.
Upon the plates x, (Figures 1, and 2,) I have. indicated thirteen districts
including its "own," say Cornhill," as connected with the Central Station,
and upon the diagram (Figure 8) these districts, each corresponding with those
mentioned on such plates a, is represented as provided with a post or mural
box constructed as hereinbefore described with reference to Figures 1, to 4,
inclusive. Should a fire break out in the district or vicinity of "Cheapside," the
Policeman or other responsible person who has discovered the outbreak thereof
will go to the post or mural box nearest to him, and provided he discovers it from
outside the district in which the fire is located, say at "Cornhill," he will shift the
bob y, of the metronome of such Cornhill " post or mural box, from its "own" or
normal position, to where is marked "Cheapside" and by releasing the detent z,
set the metronome rod w, oscillating.-The metronome thus set in motion will
oscillate with the period proper to " Cheapside" and will commutate alternating
"
"
"
currents around the series of solenoids s¹, at the Central Station. The pendulum &³,
whose period of oscillation is unisonant with the period of oscillation proper to
Cheapside " will be the only one to take up periodic swaying.-When this
Cheapside" pendulum strikes its switch, it closes the circuit through its indicator
and rings the bell D, thereby calling attention to the said indicator which, then by
exposing its "Cheapside" disc, conveys the knowledge of the fire being located in
that district. The Fireman-in charge at the Central office, then, for a few seconds.
lifts a key J, and thereby breaks the circuit and thus stops the motion of the
several needle indicators c¹, and by this indicates to the "Caller" that the alarm is
noted. The Fireman then drops the key into its normal closed position and reads
off from the needle instrument A, what is being communicated by the "Caller" on
deflecting the metronome rod w, according to pre-arranged codes.

page_text: In the event of an outbreak of fire at any of the premises electrically connected
with a post or mural box (Figures 1, and 2,) contact is made by hand, by the press
button G, or automatically, by the Thermostat K, either of which, when brought
into operation, closes the local circuit around the electro-magnet b₁, and thereby
releases the metronome rod w, which then oscillates with the period proper to its
district and thus, as herein before described, calls attention and gives the alarm at
the Central Station.
1
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is :-
First. An instrument for continuously transmitting currents of electricity of
alternating senses with any required period of transmission, substantially as
and for the purposes herein before set forth with reference to Figures 1, and 2,
of the annexed drawings.
Second. An instrument for generating and transmitting currents of Electricity
of alternating senses with any required period of transinission substantially as
and for the purposes hereinbefore set forth with reference to Figures 3, and 4,
of the annexed drawings.
Third. A receiving instrument wherein permanent magnets are caused to pass in
to and out from solenoids forming a pair through which, currents of electricity of
alternating senses are passed, substantially as and for the purposes hereinbefore
described with reference to Figures 5, and 6, of the annexed drawings.
Fourth. The arrangement and combination of mechanism whereby the closing of
a circuit is effected by the means and for the purposes hereinbefore set forth, with
reference to Figures 5, 6, and 7, of the annexed drawings.
Fifth. The method of releasing the metronome rod w, by the action of the
electro-magnet 61, and the electrical connections therewith all substantially as and
for the purposes hereinbefore set forth with reference to Figures 1, 2, and 8, of the
annexed drawings.
Sixth. The arrangement of the electrical circuits substantially as and for
the purposes hereinbefore set forth with reference to Figure 8, of the annexed
drawings.
Dated this Nineteenth day of November 1884.