IMPROVEMENTS IN FIRE-ESCAPES
Year: 1882

page_text: LETTERS PATENT to Herbert John Allison, of 41 Southampton Buildings,
Holborn, in the County of Middlesex, for an Invention of "IMPROVEMENTS
IN FIRE-ESCAPES" A communication to him from abroad by David. A. Burr,
of the City and State of New York, United States of America
PROVISIONAL SPECIFICATION left by the said Herbert John Allison at
the Office of the Commissioners of Patents on the 2nd December 1882.
"
HERBERT JOHN ALLISON, of 41 Southampton Buildings, Holborn, in the County
of Middlesex, "IMPROVEMENTS IN FIRE-ESCAPES A communication to me from
abroad by David. A. Burr, of the City and State of New York, United States of
America,
These improvements may be applied to houses already built, the parts being
enclosed in a casing, which extends up the side of the house close to the windows,
so as to be easily accessible from them, and of course the fire-escape will be applied
principally to houses already erected; but it can be built into the walls of houses
in course of erection, in which event the casing will be flush with the wall, and
will not of course be obtrusive in appearance.
Each
The fire-escape consists of a series of ladders, one for each storey of the building.
The rounds of these ladders are each hinged or pivoted to the sides of the ladders
at their outer ends, the inner ends of the rounds being pivoted between the vertical
walls. The rounds are extended somewhat beyond their pivots in the walls, so that
when the ladders fall out, when they are to be used, the rounds will be sustained
between two pins or studs, and all strain be thus taken off the pivots.
section of the ladder is provided with a tripping device to throw the ladder down
and out when it is required for use. One of these trips, which also holds the ladder
folded up in place, consists of a pivoted jaw or latch, which is held in normal
position by a coiled spring. This latch engages with a catch; on one of the rounds,
or in a notch in said round, and it is operated from the outside of the casing by a
key which can easily be reached from one of the windows of the building. When
this latch is thrown down, so as to be disengaged from the catch on the ladder-
round, the ladder section will of course fall outward and downward, and will be

page_text: sustained in the proper position by the studs. The other tripping device consists
of a series of vertically-sliding bars, one for each ladder section. These tripping-
bars are connected by a pin in one bar, which works in a slot in the bar next above
it, and they are so arranged that the pin rests in the bottom of the slot, so that the
tripping of one section of the ladder will not disturb the sections above, but the
tripping of any section above will trip all the sections below it, as will be herein-
after set forth. The end of the pivoted latch rests in a notch in the tripping-bar,
so that when the bar is thrown up it will disengage the latch from the catch on
the ladder-round and allow the section of the ladder to fall out. Instead of the
slot-and-pin connection, however, chains can be used for connecting the ends of the
bars. The sliding tripping-bar is operated by a pivoted lever within the apart-
ment. This lever connects with a bell-crank lever, which is connected by a link
with the vertically-sliding tripping-bar. By operating the lever the bar is thrown
up and the ladder-section is allowed to fall out, as above described. In order,
however, to positively insure the falling out of the ladder-section, I provide a cam-
lever, which is pivoted in the walls, and the inner end of which rests in a notch or
slot in the tripping-bar. Its outer cam end bears upon a round of the ladder, so
that when the tripping-bar is thrown up to trip the ladder the cam end is forced
against the pivoted round of the ladder and forces it out, thus overcoming any
binding or sticking that might occur, due to ice, or to rusting of the parts, or to
any other cause..
The lower section of the ladder operates an alarm, of any ordinary construction,
one of which alarms can be placed in one or more of the apartments of every floor
by which the ladder passes. A link-rod extending from the end of one of the
Jadder-rounds, preferably the one carrying the catch which engages with the tripping-
latch, is connected with a bell-crank lever, the other arm of which operates a chain
or wire, which connects directly with the alarm in such manner that when the
ladder-section is tripped and thrown out the alarm will be sounded. Thus, in case
of fire, should any one of the ladder-sections be thrown out by the person in the
building discovering the fire, the ringing of the alarm would give warning to other
occupants of the house; and should the section thrown out be the top one or one of
the upper ones, it would trip all the sections below it, as will presently be described,
and ring their respective alarms, and thus give warning of danger,
I have said that the alarins are of any ordinary construction; but they should
be so constructed that when the wire connected with a pulley in the alarm, is drawn
down and unwound by the ladder-section being folded up into place it will wind
up or compress its spring, so that it will be in order to ring when the ladder-section
is again tripped and thrown out. Where several alarms are employed each alarm
mechanism will be connected with the chain or wire above mentioned by a suitable
wire or chain, so that when the ladder is thrown out all of the alarms will be
sounded, thus giving notice of the fire to the occupants of each floor. These latter
short chains or wires will pass through openings in the wall of the building, and
will pass over suitable pulleys mounted either within the ladder-casing or in
bearings secured to the wall of the building. As the pins on the vertically-sliding
tripping-bars rest in the bottoms of the slots in the bars next above, the throwing
up of the upper bars will draw up all those below it, and thus should the topinost
bar be operated it would throw out all the ladder-sections and afford means for
escape from the top of the house down.
As an additional means of safety to the inmates of the building and a
convenience to the fire department, it is designed to place on each ladder, if so
desired, a fire-alarm box, securely locked and under control of the fire or other
authorized departments, as hereinafter described. Attached to the upper end of
the upper section of the sliding tripping-bar is a chain or cable which passes over a
pulley and then down within the case near the ground, where it will be attached
to a lever within the alarm box. The object of this arrangement is that should the
building be discovered to be on fire on the roof or elsewhere by persons outside the
house, a member of the fire department having the key to the alarm-box could

page_text: open the ladder its entire length by operating said lever, thus alarming all the
inmates of the building and notifying them to escape, and also affording facilities
for the members of the fire department to reach the flames at once.
In order to give a secure joint between the ends of the ladder-sections to prevent
lateral play or separation of the ladders from any cause, I make a notch or recess
in the upper end of the inner plate on the side of each ladder-section, and
correspondingly shape the lower end of the ladder-section next above, so that the
parts are interlocked and rendered rigid and secure.
In order to prevent the ends of the section from being battered when the ladder
is tripped and thrown out, it is designed to place a spring-cushion in the side walk
or flagging, onto which spring-cushion the lower end of the outside rail will fall
when opened. The spring can be made of solid rubber, or of a spiral spring or its
equivalent, and placed in a box.
It will be obvious that, no matter how high the ladder, each round has two stops
or pins with which to sustain its own weight, so that whether there may be one or
six sections tripped and thrown out at a time the strain on the pins would be the
same.
It is designed to put a metal covering on top of the spring-cushion and to place
the spring-cushion in such position that when the ladder is opened the lower end
of the lower outside rail will strike it before the rounds strike the stops or pins.
By this arrangement it will be observed that even if one or more of the lower
sections shall have been opened before the upper ones, this device will still act as a
spring for said upper sections, and will prevent any battering of the ends of said
sections when they strike.
The great objection to outside firo-escapes is their liability of being wet, or coated
with ice, or rendered slippery from frost, thus becoming practically useless. It has
been shown, however, that this device is closed aud therefore not liable to the
above objection; yet as a further protection it is designed (when so desired) to
cover the rounds or steps with rubber or cloth. This will also obviate the
necessity of taking hold of frosty iron in cold weather. Where no covering is used
on the rounds or steps the round itself may be corrugated, so that a person can get
a firm hold without the liability of slipping off. The rounds can be made of
tubing for lightness, and they can be cast with the hinge on, or the hinge may be
cast separate and fastened to the round by means of a screw or pin.
In order to give a supply of water in case of fire, I bring water-pipes up from
the ground through the casing and on each of the vertical walls. These pipes are
connected with pipes which extend into each apartment with which the fire-escape
is connected. The latter pipes are provided with stop-cocks and are screw threaded
for the reception of a hose, which can be kept in some convenient place within the
apartment, and, if desired, could be permanently attached to the pipe. The water
is turned on by a cock, operated by a lever connection, attached to the lower round
of the lower ladder-section, so that when that section is thrown down for use the
cock will be opened. When the ladder is closed it shuts the water off from the
pipe and opens an escape, which will be provided, to allow the water in the pipe to
run out into any suitable pipe, which can connect with the street-sewer. Of course
the arrangement for supplying water above described may be omitted and the
fire-escape used without it, if desired.
This improved fire-escape does not mar the appearance of the building, like the
unsightly stairways and other devices which have sometimes been employed; but
the ladder folds up snugly in the case, the sides being rounded and fitting over the
edges of the case present a smooth, finished appearance. It affords most ample
means of escape and of warning all the occupants of the building of danger in case
of fire. It is so constructed as to be perfectly strong and safe, and is so simple that
it may be operated by the most ignorant person. Should the lower section only be
needed in case of fire, it alone will be thrown out for use, while there will always
be a passage to the ground from whatever point at which the escape may be
needed.

page_text: If desired a weight could be substituted for the spring on the lever, whereby the
defects incident to the use of springs-such as their liability to become weakened
by long use- -will be avoided.
Means are provided for transmitting a signal to an engine house or station when
the ladder is thrown out or unfolded. This signal apparatus can be constructed in
a variety of ways, but the following is preferred, viz: the combination of the main
wire in an electric circuit and a combined circuit maker and breaker consisting of
a pivoted lever connected at one end by an insulated cord, wire, or rod with the
alarm mechanism already described. The pivot of this lever forms the contact-
point with one end of the wire. This lever is so connected with the alarm
mechanism that when the ladder is folded up and the alarm mechanism actuated to
prepare the alarm to be sounded when the ladder is next again unfolded the lever
will be turned about its pivot, so as to break the circuit. When, however, the
ladder is unfolded, the tension upon the lever will be released, and by the action
of a spring, it will be moved so as to establish the circuit and give notice to
the engine house or station, where a suitable electric-alarm apparatus will be
provided.
Of course the alarm and the circuit maker and breaker can be located in any
other desired locality; and if desired, an alarm could be located outside of the
building upon the ladder casing.
In order to strengthen the ladder casing and the ladder, and to provide a
sufficient means for securing the casing to the wall of a building, I form the sides
of said casing of L or angle iron and I form the ladder-rail of T iron. I form the
sides of the ladder-casing thicker at its angular portion, and between the ladder-
rounds and the outer thinner portion of the ladder-casing and the ladder-rounds I
arrange washers upon the pivots on which the rounds are supported and turn,
whereby the latter will be prevented from lateral vibration. These parts of the
casing that are thus reduced in thickness afford ample room for the rounds; but
when the ladder is unfolded the inner ends of the rounds will be brought into the
contracted space between the thicker portions of the casing-walls, and fit within
the space between the same, thus affording additional security against any lateral
movement or swaying of the ladder while it is in an unfolded condition.
By forming the rail of the ladder-section of T iron it can be made light, and at
the same time possess such stiffness or rigidity that it will enable the parts of the
ladder to be accurately brought into position for locking when the ladder-section
is folded into the casing.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Herbert John Allison in the Great Seal Patent Office on the
22nd May 1883.
HERBERT JOHN ALLISON, of 41 Southampton Buildings, Holborn, in the County
of Middlesex, "IMPROVEMENTS IN FIRE-ESCAPES" a communication to me from
abroad by David. A. Burr, of the City and State of New York, United States of
America,
In the accompanying drawings, Figure 1 is a vertical section taken through the
windows of a house having my improved fire-escape applied thereto. Fig. 2 is a
similar view, with the spring-receptacle for the outside rail of the lower section of
the ladder to fall upon when tripped. Fig. 3 is a detail vertical section through
the casing of the fire-escape, showing the pivoted ladders and the tripping
arrangements. Fig. 4 is a transverse section through the casing showing water-
pipe projecting into an apartment of the house. Fig. 5, a detail view, showing the
form of joint between the sections of ladder. Fig. 6 is a vertical section through
the lower part of the casing, showing the water-pipes which pass up through the
casing and the lever arrangement for turning on the water when the lower section
of the ladder is thrown down. Fig. 7 is a detail sectional view illustrating the
ladder-casing, and also showing the ladder-rail in cross-section. Fig. 8 is a
transverse section, showing my improved fire-escape built into the wall of a house.
Fig. 9 is a view similar to Fig. 1, with the lower section of the ladder thrown out,
and includes a modification. Fig. 10 is a vertical part section and part elevation,
which includes a modification; and Fig. 11 is a detail view of the catch I engaging
directly with one of the rounds.
As indicated in the drawings, my improvements may be applied to houses
already built, the parts being inclosed in a casing, A, which extends up the side of
the house close to the windows, so as to be easily accessible from them, and of
course the fire-escape will be applied principally to houses already erected; but it
can be built into the walls of houses in course of erection, as shown in Fig. 8, in
which event the casing will be flush with the wall, and will not of course be
obtrusive in appearance.
It will be observed that the fire-escape consists of a series of ladders, three,
C, D, and E, being shown, one for each storey of the building. The rounds F of
these ladders are each hinged or pivoted at ƒ to the sides F' of the ladders at their
outer ends, the inner ends of the rounds being pivoted at g between the vertical
walls G G. The rounds F are extended, as at g¹, somewhat beyond their pivots in
the walls G, so that when the ladders fall out, when they are to be used, the rounds
will be sustained between the two pins or studs h h, and all strain be thus taken of
the pivots g. Each section of the ladder is provided with a tripping device to
throw the ladder down and out when it is required for use, as shown in Figs. 1
and 2. One of these trips, H, which also holds the ladder folded up in place, as
shown in Fig. 3, consists of a pivoted jaw or latch, I, which is held in normal
position by a coiled spring, i. This latch engages with a catch, i¹, on one of the
rounds F, or in a notch in said round, as shown in Fig. 11 of the ladder section, and
it is operated from the outside of the casing by a key which can easily be reached
from one of the windows of the building. When this latch is thrown down, so as
to be disengaged from the catch on the ladder-round, the ladder-section will of
course fall outward and downward, and will be sustained in the proper position by
the studs h h. The other tripping device consists of a series of vertically-sliding
bars, J, one for each ladder-section. These tripping-bars are connected by a pin, j,

page_text: in one bar, which works in a slot, j, in the bar next above it, and they are so
arranged that the pin rests in the bottom of the slot, so that the tripping of one
section of the ladder will not disturb the sections above, but the tripping of any
section above will trip all the sections below it, as will be hereinafter set forth.
The end of the pivoted latch I rests in a notch, , in the tripping-bar J, so that
when the bar is thrown up it will disengage the latch from the catch on the ladder-
round and allow the section of the ladder to fall out. Instead of the slot-and-pin
connection, however, chains, as shown in Figs. 9 and 10, can be used for
connecting the ends of the bars J. The sliding tripping-bar is operated by a
pivoted lever, K, within the apartment. This lever connects with a bell-crank
lever, k, which is connected by a link, k, with the vertically-sliding tripping-
bar J. By operating the lever the bar is thrown up and the ladder-section is
allowed to fall out, as above described. In order, however to positively insure the
falling out of the ladder-section, I provide a cam-lever, L, which is pivoted in the
walls G, and the inner end of which rests in a notch or slot in the tripping-bar.
Its outer cam end, l, bears upon a round of the ladder, so that when the tripping-
bar is thrown up to trip the ladder the cam end is forced against the pivoted
round of the ladder and forces it out, thus overcoming any binding or sticking
that might occur, due to ice, or to rusting of the parts, to any other cause.
The lower section of the ladder operates an alarm, M, of any ordinary construction,
one of which alarms can be placed in one or more of the apartments of every floor
by which the ladder passes, as shown in Fig. 9. A link-rod, m, extending from
the end of one of the ladder-rounds, preferably the one carrying the catch which
engages with the tripping-latch I, is connected with a bell-crank lever, m¹, the
other arm of which, m³, operates a chain or wire, m³, which connects directly with
the alarm in such manner that when the ladder-section is tripped and thrown out
the alarm will be sounded. Thus, in case of fire, should any one of the ladder-
sections be thrown out by the person in the building discovering the fire, the
ringing of the alarm would give warning to other occupants of the house; and
should the section thrown out be the top one or one of the upper ones, it would
trip all the sections below it, as will presently be described, and ring their respective
alarms and thus give warning of danger.
I have said that the alarms M are of any ordinary construction; but they should
be so constructed that when the wire m³, connected with a pulley in the alarm,
is drawn down and unwound by the ladder-section being folded up into place it
will wind up or compress its spring, so that it will be in order to ring when the
ladder-section is again tripped and thrown out. Where several alarms are
employed each alarm mechanism will be connected with the chain or wire m³
by a suitable wire or chain, m', (see Fig. 9,) so that when the ladder is thrown out
all of the alarms will be sounded, thus giving notice of the fire to the occupants
of each floor. These short chains or wires m' will pass through openings in the
wall of the building, and will pass over suitable pulleys mounted either within
the ladder-casing or in bearings secured to the wall of the building. As the pins
on the vertically-sliding tripping-bars rest in the bottoms of the slots in the bars
next above, the throwing up of the upper bars will draw up all those below it,
and thus should the topmost bar be operated it would throw out all the ladder-
sections and afford means for escape from the top of the house down.
As an additional means of safety to the inmates of the building and a con-
venience to the fire department, it is designed to place on each ladder, if so desired,
a fire-alarm box, S, securely locked and under control of the fire or other authorized
departments, as shown in Fig. 10, and hereinafter described. Attached to the
upper end of the upper section of the sliding tripping-bar J is a chain or cable
which passes over a pulley, j, Fig. 10, and then down within the case near the
ground, where it will be attached to a lever, y, within the alarm box S. The
object of this arrangement is that should the building be discovered to be on fire
on the roof or elsewhere by persons outside the house, a member of the fire
department baving the key to the alarm-box could open the ladder its entire length

page_text: by operating said lever, thus alarming all the inmates of the building and notifying
them to escape, and also affording facilities for the members of the fire department
to reach the flames at once.
In order to give a secure joint between the ends of the ladder-sections to prevent
lateral play or separation of the ladders from any cause, I make the upper end
of each ladder-section, and the lower end of the ladder-section next above, so that
the parts interlock and are rendered rigid and secure.
In order to prevent the ends of the section from being battered when the ladder
is tripped and thrown out, it is designed to place a spring-cushion, S³, in the side-
walk or flagging, onto which spring-cushion the lower end of the outside rail will
fall when opened. The spring can be made of solid rubber, or of a spiral spring
or its equivalent, and placed in a box, T, Fig. 9.
It will be obvious that, no matter how high the ladder, each round has two
stops or pins, h h, with which to sustain its own weight, so that whether there
may be one or six sections tripped and thrown out at a time the strain on the pins
would be the same.
It is designed to put a metal covering on top of the spring-cushion and to place
the spring-cushion in such position that when the ladder is opened the lower end
of the lower outside rail will strike it before the rounds strike the stops or pins h h.
By this arrangement it will be observed that even if one or more of the lower
sections shall have been opened before the upper ones, this device will still act as
a spring for said upper sections, and will prevent any battering of the ends of said
sections when they strike.
The great objection to outside fire-escapes is their liability of being wet, or
coated with ice, or rendered slippery from frost, thus becoming practically useless.
It has been shown, however, that this device is closed and therefore not liable to
the above objection; yet as a further protection it is designed (when so desired)
to cover the rounds or steps with rubber or cloth. This will also obviate the
necessity of taking hold of frosty iron in cold weather. Where no covering is
used on the rounds or steps the round itself may be corrugated, so that a person
can get a firm hold without the liability of slipping off. The rounds can be
made of tubing for lightness, and they can be cast with the hinge on, or the
hinge may be cast separate and fastened to the round by means of a screw or pin.
In order to give a supply of water in case of fire, I bring water-pipes O up
from the ground through the casing A, and on each of the vertical walls G. These
pipes are connected with pipes o, Fig. 2, which extend into each apartment with
which the fire-escape is connected. These pipes o are provided with stop-cocks o¹,
and are screw-threaded at o* for the reception of a hose, which can be kept in
some convenient place within the apartment, and, if desired, could be permanently
attached to the pipe. The water is turned on by a cock, P, operated by a lever-
connection, p, attached to the lower round of the lower ladder-section, as shown in
Fig. 6, so that when that section is thrown down for use the cock P will be opened.
When the ladder is closed it shuts the water off from the pipe and opens an
escape, pl, which will be provided, to allow the water in the pipe to run out into
any suitable pipe, which can connect with the street-sewer. Of course the arrange-
ment for supplying water above described may be omitted and the fire-escape used
without it, if desired.
My improved fire-escape does not mar the appearance of the building, like the
unsightly stairways and other devices which have sometimes been employed; but,
as shown in the drawings, the ladder folds up snugly in the case A. It affords
most ample means of escape and of warning all the occupants of the building of
danger in case of fire. It is so constructed as to be perfectly strong and safe, and
is so simple that it may be operated by the most ignorant person. Should the
lower section only be needed in case of fire, it alone will be thrown out for use,
while there will always be a passage to the ground from whatever point at which
the escape may be needed.
If desired, a weight, ³, could be substituted for the spring i on lever I, as shown

page_text: in Fig. 11, whereby the defects incident to the use of springs-such as their
liability to become weakened by long use-will be avoided.
In Fig. 9, I have shown means for transmitting a signal to an engine house or
station when the ladder is thrown out or unfolded. This signal apparatus can be
constructed in a variety of ways; that shown, however, being sufficient to illustrate
my invention. In said Figure, R indicates the main wire in an electric circuit,
and a combined circuit maker and breaker, consisting of a pivoted lever connected
at one end by an insulated cord, wire, or rod with the alarm mechanism M, already
described. The pivot of this lever forins the contact-point with one end of the
wire, the other contact being indicated at r'. This lever is 80 connected with the
alarm mechanism M that when the ladder is folded up and the alarm mechanism
actuated to prepare the alarm to be sounded when the ladder is next again
unfolded the lever will be turned about its pivot, so as to break the circuit.
When, however, the ladder is unfolded, the tension upon the lever will be released,
and by the action of a spring, 2, it will be brought from the position shown in
dotted lines to that shown in full lines, thereby establishing the circuit and giving
notice to the engine house or station, where a suitable electric-alarm apparatus
will be provided.
Of course the alarm M and the circuit maker and breaker can be located in any
other desired locality than that herein shown; and, if desired, an alarm could be
located outside of the building upon the ladder-casing.
In order to strengthen the ladder-casing and the ladder, and to provide a
sufficient means for securing the casing to the wall of a building, I form the sides
of said casing of L or angle iron, as particularly shown in Fig. 7, and I form the
ladder-rail of T-iron, as also shown in said Figure. I form the sides of the ladder-
casing thicker at its angular portion, as at S, and between the ladder-rounds and
the outer thinner portion, 8, of the ladder-casing and the ladder-rounds I arrange
washers f, upon the pivots on which the rounds are supported and turn, whereby
the latter will be prevented from lateral vibration. These parts of the casing that
are thus reduced in thickness afford ample room for the rounds; but when the
ladder is unfolded the inner ends of the rounds will be brought into the contracted
space between the thicker portions 8' of the casing-walls, and fit within the spaco
between the same, thus affording additional security against any lateral movement
or swaying of the ladder while it is in an unfolded condition.
By forming the rail of the ladder-section of T-iron it can be made light, and at
the same time possess such stiffness or rigidity that it will enable the parts of the
ladder to be accurately brought into position for locking when the ladder-section
is folded into the casing.
Having thus described my invention, what I claim is :-
1. The combination, in a fire-escape, of, the pivoted ladder-section with the
vertically-sliding bar J, the spring-latch I, pivoted to the fixed casing, and the
catch ', secured to one of the ladder-rounds, as described.
2. The combination of the pivoted ladder-section with the latch I, the vertically-
sliding bar J, with slots or notches, in which one end of said latch rests, the cam L,
and a spring or weight connected with the latch, substantially as described.
3. The combination of the ladder-section, the vertically-sliding tripping-bar,
mechanism operated by the bar to trip the ladder, the operating-lever within
the apartment, and the lever-connection with the tripping-bar, substantially as
set forth.
4. The combination of the tripping-lever within the apartment, the bell-crank
lever, and the connections between it and the tripping-lever, and vertically-
sliding tripping-bar, the latch operated by it, and the pivoted ladder, substantially
ns set forth.
5. The combination of the pivoted ladder-section, the connecting-rod m, extending
from the end of the rounds of the ladder to the bell-crank lever, the wire m³, the
alarm M, and mechanism for tripping the ladder and sounding the alarm,
substantially as set forth.

page_text: 6. The combination of the pivoted ladder-section, the system of water-pipes, the
cock in the water-pipe, the lever-connection with the pivoted ladder, and mechanism
for tripping the ladder, and thus turning on and off the water, substantially as
set forth.
7. The combination of the pivoted ladder-section with the tripping mechanism
operated by the sliding bar J to trip the ladder, the alarm-box at the foot of the
ladder, and the wire passing from the alarm-box up over a pulley and connecting
with the slide-bar of the upper section of the ladder, whereby the ladder can be
thrown out by a person controlling the end of the wire at the alarm-box,
substantially as described.
8. The combination of the ladder-section with mechanism for tripping the
ladder, and the spring-cushion arranged to receive the lower end of the outer ladder-
rail when the ladder is tripped, and to thereby take up the shock, substantially as
described.
9. The combination, with the ladder capable of being folded and unfolded,
substantially as described, of an electric circuit maker and breaker located in an
electric circuit and controlled by the movement of the ladder, so as to establish
the circuit when the ladder is unfolded, for the purpose of giving an alarm at some
remote station.
10. The combination, with the pivoted ladder-section, of the L or angle iron
forming the two sides of the casing, through which the bolts pass to secure the
same to a building, said sides being thickened near their corners to form a
contracted space, in which the ends of the ladder-rounds fit when the ladder is
unfolded, substantially as described.
In witness whereof, I, tho said Herbert John Allison, have hereunto set my
hand and seal, this 22nd day of May, in the year of our Lord one thousand
eight hundred and eighty-three.
HERBERT. J. ALLISON. (L.S.)