AN IMPROVED. MEANS FOR MAKING SIGNALS ON RAILWAY TRAINS BETWEEN THE GUARD AND DRIVER RESPECTIVELY, AND BETWEEN THE PASSENGERS AND GUARD AND DRIVER, AND OF GIVING NOTICE TO THE GUARD AND DRIVER IN CASE OF THE ACCIDENTAL SEVERANCE OF THE PARTS OF A TRAIN; WHICH INVENTION IS APPLICABLE ALSO TO STEAM SHIPS, FACTORIES, AND OTHER PLACES WHERE, IT MAY BE REQUISITE TO. COMMUNICATE WITH DISTANT POINTS
Year: 1856

page_text: TERS PATENT. to Thomas Arthur Dillon, of the Registry of Deeds
Office, in the County of the City of Dublin,, and John Gray, M.D.,
of 4,and 5, Princes Street, in the County of the City of Dublin, Esquires,
for the Invention of "AN IMPROVED. MEANS FOR MAKING SIGNALS ON
RAILWAY TRAINS BETWEEN THE GUARD AND DRIVER RESPECTIVELY, AND
BETWEEN THE PASSENGERS AND GUARD AND DRIVER, AND OF GIVING NOTICE TO
THE GUARD AND DRIVER IN CASE OF THE ACCIDENTAL SEVERANCE OF THE
PARTS OF A TRAIN; WHICH INVENTION IS APPLICABLE ALSO TO STEAM SHIPS,
FACTORIES, AND OTHER PLACES WHERE, IT MAY BE REQUISITE TO. COMMUNICATE
WITH DISTANT POINTS,"
aled the 10th March 1857, and dated the 30th September 1856?
PROVISIONAL SPECIFICATION left by the said Thomas Arthur Dillon
and John Gray at the Office of the Commissioners of Patents, with
their Petition, on the 30th September 1856...
We, THOMAS ARTHUR DILLON, of the Registry of Deeds Office, in the
County of the City of Dublin, and JOHN GRAY, M.D., of 4 and 5, Princes
Street; in the County of the City of Dublin, Esquires, do hereby declare the
nature of the said Invention' for AN IMPROVED MEANS FOR MAKING SIGNALS
ON RAILWAY TRAINS BETWEEN THE GUARD AND DRIVER RESPECTIVELY, AND BETWEEN
THE PASSENGERS AND GUARD AND DRIVER, AND OF GIVING NOTICE TO THE GUARD
[Price Sd.]

page_text: AND DRIVER IN CASE OF THE ACCIDENTAL SEVERANCE OF THE PARTS OF A TRAIN;
WHICH INVENTION IS APPLICABLE ALSO TO STEAM SHIPS, FACTORIES, AND OTHER PLACES
WHERE IT MAY BE REQUISITE TO COMMUNICATE WITH DISTANT POINTS," to be as
follows:-
The object of our Invention is to secure a means of communicating
between the guard and the driver, and between passengers, in certain cases,
and the guard, driver, or other persons in charge of the train in case of
accident, danger, &c., and of giving notice to the guard and driver respec-
tively in case of the severance of one part of a train of carriages from
another, and generally of giving signals at distant points.
The means employed for this purpose is an arrangement by which atmo-
spheric pressure is brought into action by a mechanism of the nature of an
air
pump, , to which,motion is given by power derived from a prime mover, or,
in case of railway trains, from the axle wheel or other moving part of the last
or some other of the carriages of which the train consists, and by suitable
mechanical adjustments caused to act on a steam-cock with whistle attached,
a bell, a semaphore, or other ordinary signal. When applied to railway trains,
a steam whistle and semaphore may be placed near the driver, and a bell
placed near the guard, and the mechanical adjustments so arranged as to open
the steam cock and cause the whistle to sound, to cause the semaphore to
indicate danger, and the guard's bell to ring in the event of the severance of
one part of the train from another, said arrangement being also of such a
nature as as to enable the guard at his discretion to give notice to the driver,
the driver to give notice to the guard in case of danger, and the passengers
to give notice to both in case of fire or other emergency.
In order, however, that the nature of our said Invention may be better
understood, we will state one of the means by which it is carried into effect,
selecting for illustration its application to a railway train. We place and
secure in a suitable position along the side or under each carriage a tube of
sinall bore,say, th incli,which may be of metal or any other suitable material,
furnished with elastic or other suitable flexible connexions, by which junctions
are so formed between the several carriages that the tube becomes continuous
along the whole train, and is more or less air-tight, the connexions being of
such a nature (to be hereafter described) that they are not strained when the
carriages are as far asunder as their usual "conplings" admit of, and that-
one carriage tube connexion will be detached from that of the next one,
without being broken or otherwise injured, should the carriages be forcibly.
separated by accident.or neglect. To the end of this tube, which is securely
placed on 'the last or guard's carriage, an apparatus of the nature of an

page_text: "
exhausting or air pump is attached, which is connected by means of a shaft,
drum, and belt, or other suitable means of communicating motion with one
of the axles of the said carriage. The other end of the tube, which is placed on
the engine is attached to the top of a cylinder, in which a moveable piston or
plunger plays; the piston rod is reversed and projects downwards below the
cylinder. This rod is so weighted, and is, by means of a lever or levers
with their adjustments requisitely modified; so connected with a semaphore
and with the head of a cock placed on a steam pipe that issues from the
boiler,aud is furnished with a whistle, that when the cylinder is not exhausted,
the piston gravitates to the lower end, the lever opens the steam cock, and the
whistle is acted on, and the semaphore is brought to the position indicating
"danger;" but when the pump at the other end of the train by its action
more or less perfectly exhausts the air in the tube and in the cylinder in
which it terminates, the piston is pressed upwards into the cylinder by the
atmospheric pressure, the lever shuts off the steam, and thus stops the action
of the whistle, and at the same time removes the semaphore from the position
indicating danger.". The motion of the axle, when the train is started, com-
municates motion to the shaft and drum by a belt, in case that mode of
communicating motive power is adopted, and theuce bya suitable arrangement,
as of a crank or stud to the exhausting pump, which rapidly so exhausts the
air in the tube stretched along the carriages,and in its connexions, and in the
cylinder, that the steam cock is closed, and the semaphore brought to the
position indicating "safety" by the ascent of the afore-mentioned piston, in
which condition it is obvious they will remain while the pump continues to
act, and while the tube and its connexions are more or less completely
exhausted. The interruption of the continuity of the tube, caused by the
severance of it or any of the connexions at any point, would, by opening a
passage-for the supply of air to the partially exhausted cylinder, and by sup-
plying air to the pump, cause the piston to be depressed by its own weight,
open the steam cock, cause the whistle to sound, and cause the semaphore to
indicate danger;" and this occurs in case of accidental severance of the
parts of a train in motion. By means of a pipe furnished with a stop-cock,
anil placed on the part of the tube near the guard's scat, the guard can admit
air into the tube at his discretion, so as to produce the results described above
as those which would result from the accidental severance of the continuity
of the tube. In order to enable the driver or parties in the intermediate
carriages to communicate with the guard, we place, on the tube and near to
the pump,an air-tight flattened circular box, into which the tube enters at one
side; on the other side of the box we place an exit tube; thus, the box so
15

page_text: forms a part of the tube that the air drawn from the tube and cylinder
must pass through this box to the pump. In this box is placed a fixed par-
tition, extending nearly half way across, and a vane or valve, secured to a
shaft or spindle which passes through one side of the box, and carries a
hand or hammer. The hand is so placed that when the pump exhausts the air
in the upper part of the box, more air from the tube and cylinder passes
into the lower part to supply the place of that abstracted, and forces the
vane upwards by its passing towards the pump, which, by partially revolving
the pinion or shaft,carries up the hand or hammer so as to strike a bell placed
near to it; so long as the cylinder and tube supply air in sufficient quantity to
carry up the vane by its motive force the bell will be struck at each stroke of
the pump. The interruption of the continuity of the tube, after exhaustion, by
an accident or otherwise, would, it is obvious, cause the pump again to receive
air in quantity through the box, and the bell to be struck. It is also obvious
that the driver, by opening a cock placed on a branch tube near him, can
at any time reproduce a current sufficient to cause the guard's bell to be
struck. A branch pipe furnished with a cock, placed in any of the carriages,
enables a passenger to cause the guard's bell to be struck, and to open the
cock of the driver's whistle herein-before described; such pipe and cock, by
being covered with glass in a passenger carriage, would be sufficiently pro.
tected, and yet afford a secure means of giving notice in case of fire or
other emergency. It is obvious that the destruction of the pipe by fire or
any other cause would give similar notice.
The connexions we use are peculiar, and consist essentially of an arrange-
ment which forms an air-tight connexion which is not liable to severance by
the motion of the carriages, and is, nevertheless, capable of being freed without
injury or breakage by a forcible drag, such as would result from the severance
of a train by accident, or the removal of a carriage from a train. They consist
of a male and female tube, the former of which passes freely but not loosely
into the latter, for, say, about 4 inches, and is grasped by an elastic substance
placed in an enlargement of the body of the female tube, as a tube of india-
rubber or a ring or diaphragm of india-rubber with an aperture in its centre
much less than the diameter of the male tube. These connexions may be
partly of metal or of india-rubber alone, or of any suitable material that will
fulfil the intentions above described,as wooden or bone tubes with india-rubber
or other elastic ring or diaphragrain. They are attached by flexible pendents
and coupling joints to the fixed tube which traverses the carriage.
The over exhaust of the pump may be relieved bya safety valve, so weighted
that after the piston in the cylinder is fully brought up, the valve will open

page_text: and ease the pump by supplying air in suitable quantity. The motion of this
valve may be made to regulate the motion of the pump after the manner of
a governor.
These arrangements we have varied in some cases, occasionally using the
pinion and wheel or the conical drums (which we prefer) to regulate the
motion of the pump.
We have also used the pump to force air along the tube into the cylinder,
and thus reverse the action, but we prefer the pressure of an exhaust to that
of force.
In some cases, as in its application to steam ships and factories, a double
or return tube may be used with advantage, as it may be an object to place
the pump in communication with the prime mover.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Arthur Dillon and John Gray in the Great
Seal Patent Office on the 30th March 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, THOMAS
ARTHUR DILLON, of the Registry of Deeds Office, in the County of the
City of Dublin, and JOHN GRAY, M.D., of 4 and 5, Princes Street, in the
City of Dublin, Esquires, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of September, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth and twenty-first
year of Her reign, did, for Herself, Hei heirs and successors, give and grant
unto us, the said Thomas Arthur Dillon and John Gray, Her special licence,
that we, the said Thomas Arthur Dillon and John Gray, our executors, admi-
nistrators, and assigns, or such others as we, the said Thomas Arthur Lillon
and John Gray, our executors, 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 Ireland,
the Channel Islands, and Isle of Man, an Invention for "AN IMPROVED MEANS
OF MAKING SIGNALS ON RAILWAY TRAINS BETWEEN THE GUARD AND DRIVER
RESPECTIVELY, AND BETWEEN THE PASSENGERS AND GUARD AND DRIVER, AND OF
GIVING NOTICE TO THE GUARD AND DRIVER IN CASE OF THE ACCIDENTAL SEVERANCE
OF THE PARTS OF A TRAIN; WHICH INVENTION IS APPLICABLE ALSO TO STEAM SHIPS,
FACTORIES, AND OTHER PLACES WHERE IT MAY BE REQUISITE TO COMMUNICATE WITH

page_text: DISTANT POINTS," upon the condition (amongst others) that we, the said Thomas
Arthur Dillon and John Gray, by an instrument in writing under our hands
and seals, particularly describe 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 we, the said Thomas Arthur Dillon and John Gray,
do hereby declare the nature of our said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement, that is to say:-
The object of our Invention is to secure a means of communicating
between the guard and the driver, and between passengers, in certain cases,
and the guard, driver, or other persons in charge of the train, and of giving
notice to the guard and driver respectively of a train in motion, in case of
the severance of one part of the train of carriages from another, and
penerally of giving signals between distant points.
The means employed for this purpose consist of an arrangement by which
atmospheric pressure is brought into action by a mechanism of the nature of
an air pump acting on an air tube or pipe, either by exhausting the air from
or forcing air into the tube, and thus giving motion to a piston or to a vane,
Motion
or to other similar contrivance in connexion with the air tube M.
may be given to the air pump by power derived from a prime mover, or, in
case of railway trains, from the axle wheel or other moving part of the last
or some other of the carriages of which the train consists, and by suitable
mechanical adjustments, which are more particularly described and explained
by the statement herein-after made, and by the Drawings attached, with the
letters and figures thereon. The atmospheric air is made to act on a
steam cock with whistle attached, a bell, a semapliore, or other ordinary
signal. When applied to railway trains, and when the pump is used to
exhaust the air from the tube, we place a steam whistle and semaphore near
the driver, and a bell or whistle, a semaphore, or other signal near the guard;
and the details of the apparatus are so arranged that should a severance of the
train and the air tube or its connexions take place, the atmospheric air will
be admitted into the air tube, which had been more or less exhausted, and
will act on the mechanical adjustments, and cause them to open a steam cock
near the driver, cause the whistle to sonud,the semaphore to indicate danger,
and the signals in the guard's van to give similar indications. The arrange-
ment is also of such a nature as to enable the guard and driver respectively, at
their discretion, to give notice one to the other in case of danger; and generally

page_text: to communicate by a code of signals; and is also such as may be so adjusted
as to enable the passengers to give notice to the guard or driver, or to both,
in case of fire or other emergency.
In order, however, that the nature of our said Invention may be better
understood, we will proceed to explain, with the aid of the accompanying
Drawings, and of the letters and figures thereon, one of the modes by
which our said Invention is carried into effect, selecting for illustration a
mode of its application to a railway train.
We place and secure in a suitable position along each carriage A, A, Fig. 1,
a tube B, B, which is of small bore, say, th inch to inch diameter, and
which may be of metal, gutta percha, or any other suitable material, furnished
with flexible pendants C, and with connexions D, by which junctions are
so formed between the tubes attached to the several carriages that the tube
becomes continuous along the whole train, and is more or less air-tight. The
pendants and the connexions are of such a nature (to be herein-after more
particularly described), that they are not strained when the carriages are so
far asunder as their usual "couplings" admit of, and that one carriage tube
connexion may be detached from that of the next one without being broken
or otherwise injured should the carriages be forcibly separated by accident or
neglect. The end of this continuous tube, which is usually placed on the last
or on the guard's carriage, terminates in an apparatus of the nature of an
exhausting or air pump, shewn in situ at E, Fig. 1, and shown detached at E,
Fig. 3.
This air pump is connected by a crank (F, Fig. 3), a shaft (G,
Fig. 3), a drum (H, Fig. 3), and a belt (I, Fig. 3), with one of the axles
(J, Fig. 3,) of the carriage, by means of which motion is communicated to the
pump from the wheel; thus, when the train is in motion the pump is in
action. The other end of the continuous train tube terminates in a signal
box (K), which is placed on the engine in front of the driver (K, Fig. 1), and
opens into the top of a cylinder (L, Fig. 4), placed in the signal box. A
moveable piston or plunger (M, Fig. 4,) plays, more or less air-tight, in this
cylinder, the piston rod being reversed and projecting downwards below the
cylinder; when the pump has withdrawn, more or less perfectly, the air con-
tained in the tube and the cylinder, the atmospheric pressure forces the piston
upwards into the cylinder, and when air is re-admitted into the cylinder in
sufficient quantity, which either the guard or the driver can do at his discretion;
by opening an air or signal cock placed on the tube, or on a branch tube of
equal dimentions, as shown at *, Fig. 1, the exhaust being destroyed, the piston
descends and resumes its former position. This piston rod is so connected with
a bar or semaphore N, by a pin which works in a slot, or by any other

page_text: suitable means, that its motion upwards gives motion in a similar direction to
the bar. One end of this bar or semaphore fits on to the head of a cock
O, Fig. 4, inserted in a steam pipe P, Fig. 4, which issues from the boiler,
and is furnished with a whistle Q, Fig. 4. This cock acts as a pivot for the
bar or semaphore, and the motion of the bar turns the cock, as would the
motion of an ordinary handle, and shuts the steam way or opens it, according
as the direction of the motion may be upwards or downwards, and thus the
whistle may be either silenced or made to sound, as may be required. Thus,
when the pump sufficiently exhausts the train tube and cylinder, the piston is
pressed upwards, the bar is lifted and passes away from the field of the
spectacle R, Fig. 4, to the position marked by the dotted lines S, Fig. 4,
where it is not visible to the driver; and the steam is shut off by the cock.
But when air is admitted to the tube and cylinder so as to destroy the exhaust,
the piston gravitates to the lower end of the cylinder, the bar or semaphore
falls to the position indicating danger, viz., across the spectacle, as shown at.
N, Fig. 4, and in falling turns and opens the steam cock (O, Fig. 4,), and
the whistle (Q, Fig. 4,) is acted on by a jet of steam which rushes from the
boiler through the now open cock. When the train is in motion and the pump
in full action, the opening and closing of an air signal cock placed near the
guard or near the driver, or on any part of the tube, will; by alternately
admitting and shutting off air, alternately produce the conditions above
described, and by this means a code of signals may be transmitted between
guard and driver. It is obvious that the interruption of the continuity of the
tube by any severance of the connexions, such as would result from the
severance of a train in motion, would open the tube to the free admission of
air, and produce the signals, just as would the admission of air by the discre-
tionary opening of a signal cock, and thus, in case of an accident of this
description, the apparatus becomes a self-acting danger signal:
In order to enable the guard or other person to test the connextions and
ascertain whether the air tube is sufficiently air-tight, whether all the parts are
in working order, and whether all the tubes of the carriages of the train have
been duly connected before the train is put in motion, and in certain cases to
enable him to give a signal for starting the train, or to have the apparatus in
full action and fit for signalling at the moment of starting, we make an
arrangement of the ordinary character, as by a lose pulley or by gearing
teeth; to enable biin to work the pump with his hand, or we attach to the
train tube a separate apparatus of the nature of a pump, by which he can
exhaust the tube while the train is stationary. This arrangement is so
obvious as not to require the aid of Drawings to render it intelligible.

page_text: The air or signal cocks are ordinary stop-cocks, placed on branch pipes, or
they may be with advantage two-way cocks, placed on the train tube itself.
The signal cocks are shewn at T, Fig. 4, which is the driver's signal cock,
and at T, Fig. 5, which is the signal cock on the guard's signal box. The
two-way cocks are so well known as not to require special description. We
occasionally use a three-way cock to connect the train tube of a line of
carriages placed behind the guard's van, or the van or carriage in which
the exhaust pump works. It enables the guard, if there be carriages added
behind his van, to bring the back tube of his van which is connected with
the back carriages into connextion with the train tube in front, or to shut it
off, if there be not such carriages, by merely turning the handle of the cock
in the direction indicated by the air-ways.
In order to enable the driver or parties in the intermediate carriages to
communicate with the guard, we place on the line of tube, so as to form a
part of it, and in the guard's van or near to the pump, an air-tight box, with
a vane in it, so situate that the air passing to the pump must pass into the
box at one side of the vane, and turn the vane partially round, in order to
reach the exit pipe. An arm, placed on the prolonged axle of this vanc, and
playing outside this box, would at each motion of the vane be made to revolve
with the vane, and to strike a bell. By this arrangement, whenever a
severance would take place, or when a signal cock would be opened, the full
charge of air passing through the box to the pump, would cause the bell to
be struck at each stroke of the pump.
An equally effective result can be produced by placing, in connexion with
the exit valve through which the air is expelled from the pump, a tube with a
whistle on its extremity. When air is supplied to and expelled from the pump
in quantity, it is forced through this whistle, which by its sound attracts the
guard's attention. This arrangement will be better understood by referring
to Fig. 3, where the exit pipe U, is shewn with a whistle on top.
We
It is obvious that this arrangement might be varied in its details.
have occasionally used for the same purpose a small pendulum, consisting
of a metal cup or disk about two inches in diameter, suspended by a line or
slight rod placed near a bell, near to and opposite a pipe leading from the
exit valve of the pump; the forcible expulsion of the air will cause the bell
be struck by this pendulum.
In some cases we have placed in the guard's van a signal box (K, Fig. 5,)
with a cylinder and piston, a bar or a semaphore of nearly the same character
as that placed in the driver's box. The air tube of the train terminates in one
side of the top of this cylinder, and the exhausting tube of the pump V,

page_text: Fig. 5, draws the air from the other side of this cylinder by a tube of much
smaller dimensions than the train tube which terminates in the cylinder, or
through a long tortuous pipe. The opening of the driver's signal cock, or of
the signal cock on any other part of the train, or the severance of the
connexions, will admit air more quickly into the cylinder by the large open of
the train tube than the pump can draw it off by the smaller tube, and will
thus cause the cylinder to be partially filled with air, and the semaphore to fall
across the field of the spectacle R, Fig. 5. If the semaphore be attached
to a cock on the exhaust tube of the pump, say, at + Fig. 5, and made to
turn that cock as the semaphore in the driver's box turns the steam cock, by
its motion upwards, and as the consequence of the exhaust of the cylinder, to
turn the cock so as to nearly close the air passage to the pump from the
cylinder, the small passage thus left will be sufficient, when the semaphore is
up,to maintain the exhaust in the cylinder; but when the tube connexions are
severed, or the driver's or other signal cock opened; the passage through the
cock to the pump will be too small to allow all the air admitted to the cylinder
to be carried off, and the cylinder will become partially full, and the semaphore
will fall, and either remain down or oscillate, according to the power of the
pump relatively to the size of the cylinder, or of the train air tube, and to the
opening of the exhaust tube in the cylinder, or length of the coiled tube
through which the air will have to pass to the pump, the air expelled from the
pump acting at the same time on the whistle or bell, as may be arranged.
The cylinder in which the piston, plays, and the piston itself, may be of the
ordinary kind. We generally make the cylinder about 2 inches in diameter,
and give the piston a two-inch stroke. It is a great advantage to have the
piston play with little friction, and be as nearly as possible air-tight, and we
have for our more delicate apparatuses made the piston to play loosely in the
cylinder, securing the air-tightness by making it as shown in Drawing N, 6.
The cylinder is about two inches long, aud the piston has two heads on it,
one (M), which plays in the cylinder, and the other (W), which serves as the
bottom, on which a tube of india-rubber (X), is secured. The india-rubber
tube is about the same diameter as the cylinder, and about 2 inches long.
One end of it is secured round the bottom of the cylinder, or on a perforated
cap or ring (Y, Fig. 6,) which screws on the bottom of the cylinder, and the
other end on the second head of the piston (W, Fig. 6), two or more rings
are pressed into the india-rubber tube (as shown in the Drawing), and the
tube securely tied on to them, in order to prevent its collapsing inwards when
the air is withdrawn. The result is that when thé exhaust is produced by the
pump, the india-rubber tube collapses upwards (as shown in Fig. 7). This

page_text: gives an absolutely air-tight cylinder. It is obvious that this modification
might be varied in several ways.
The pendants (C, Fig. 2,) which we use to connect the train tube between
carriage and carriage, are made of canvass, rendered air-tight by a coating of
india-rubber, and non-compressible by atmospheric pressure by a spiral wire
which runs through each of them. We are not, however, to be understood as
confining ourselves to this material, as we have effectively used other sub-
stances, as gum-elastic, gutta percha, &c., &c. They are securely fastened at
one extremity on the ends of the carriage tubes, and at the other to the con-
nexions (D, Fig. 2). The connexions consist essentially of a male and
corresponding female tube, which are placed on the pendants of opposite
carriages. The male tube, which is of less diameter than the female, passes
freely but not loosely into the latter for about four inches. In the Drawing
attached, we show one mode of making these connexions, in which the centre
part of the female tube consists of a tube of elastic india-rubber a, Fig. 2,
about 2 or 3 inches long, tied on the metalic parts of the female tube, which
are kept in the proper position by being connected by metalic bands to the
male tube. The back part. Fig. 2, of the male tube opening directly
into and being soldered to the female tube, so as to form a continuous open
tube with it when the carriages are connected. The male tube passes into
this elastic part of the female tube, and is so tightly compressed by it that no
air can pass between their surfaces into the general train tube while in situ.
This double connexion tube is used to allow of the reversing of any carriage
forming a part of a train; each connexion thus made presenting both a
male and a female part.
But we are not to be understood as confining ourselves to this mode of
making the connexions, having used other forms, as, for example, adiaphragm
of india-rubber placed in the body of the female tube,with a small hole in the
centre for the male tube to pass through, has been found to serve the same
purpose as the india-rubber tube in the female part of the connexion. We
have also effectively used the common piston head of a syringe placed on a
tube for the male connexion, and a corresponding cylinder for the female.
Having now described one mode in which our said Invention may be carried
into operation, we wish to observe that, in some cases, we have considerably
varied the details of its application in practice; and in order that this state-
ment may be better understood, we will illustrate our meaning by explaining
some of the modifications we have adopted for giving signals to the guard.
We have, instead of a single tube, used a bent tube reaching from the
pump through the driver's signal box, and beut back on itself to the guard's

page_text: signal box, with the requisite connexions between the carriages, and by this
means we have enabled the driver to communicate with the guard without
affecting the signals placed near himself, and have enabled passengers to com-
municate with the guard, so as to give a signal to him and not to the driver.
This will be better understood by referring to the plan of the bent or double
tube given at Fig. 8, in which P is the pump; D, the driver's box; G, the
guard's signal box; C, the passenger's signal cock; Dc,the driver's signalcock.
If the signal cock used in each case be a two-way cock, it is obvious that the
air can be admitted to the guard's signal box (G) by turning the two-way
cock (C),without admitting it to the pump (P), or the driver's signal box, and
thus the passengers may signal the guard, leaving it to the guard's discretion
whether he will signal the driver or not. This might be modified by sending
a seperate tube from the pump along the passengers' carriages with a sepe.
rate valve and cocks and a signal box on it, and in other We have also
ways.
modified the steam cock used in connexion with the driver's signal box, in
such a manner that the lifting of the semaphore will open one of the steam
ways of a two-way cock, at the same time closing the other steam way which
was open when it was down, and the dropping of it will re-open the steam
way which was shut by the lifting of it, and close the steam way which was
open when it was up. There is added an arrangement which enables the
driver to shut off steam from the steam way which has been opened by the
lifting up or the depressing of the semaphore, leaving the steam passage open
to the steam way of the two-way cock that has been closed, but which the
lifting or the dropping of the semaphore, as it may be,, will re-open on the
next change of the position of the semaphore. This modification will be better
understood by reference to Drawing (Fig. 9), in which (a) is the steam pipe
from boiler; (b, b,) branch steam pipes, each having a plug (c, c+,) worked by a
handle (d), common to both, the steam passages in the plugs being reversed,
so that when the handle is turned so as to open one, it closes the other. The
branch pipes (e,e+,) passing from the plugs (c,c+,) enter the two-way cock (),
which the semaphore turns, and which corresponds to the cock (o, Fig. 4),but
at different points. This cock (f) will obviously admit steam to the whistle
whenever the semaphore turns the cock, so as to present an open way to that
branch (be it e or e+), to which it is admitted by the peculiar position of the
handle (d). This arrangement enables us to cause the apparatus to sound the
whistle on the exhaust being perfected, when the driver may shut steam off
from the branch (e or e+), leaving the steam free to the other branch (e or e+),
as it may be, corresponding to the steam way which will be opened in the
two-way cock (, Fig. 9,) by the next change of the semaphore.

page_text: Having thus described the nature of our Invention, and in what manner the
same is to be performed, we would have it understood that we do not con-
fine ourselves to the precise forms and arrangements of the parts of the
apparatus shown and described, and that although we have shown some modi-
fications of the same by which the objects in view may be accomplished, yet
we do not confine ourselves to such forms, nor to the precise positions of the
parts, or of any of them; but what we do claim as secured to us by the above
in part recited Patent is, the combination of a mechanism of the nature of an
air pump, with pipes or tubes and with reservoirs, capable of having their
shapes or dimensions altered by the forcing or admitting of air into them, or
by the exhausting of air from them, and of communicating motion by such
changes, and with a signalling mechanism, by means of which signals may be
made through the agency of atmospheric air, either at discretion, or, in
certain cases by a self-acting arrangement, as described.
In witness whereof, we, the said Thomas Arthur Dillon and John Gray,
have hereunto set our hands and seals, the Twenty-fifth day of March,
in the year of our Lord One thousand eight hundred and fifty-seven.
THOMAS ARTHUR DILLON. (L.B.)
JOHN GRAY, M.D.
(L.S.)
Signed, sealed, and delivered in the
presence of
THOMAS WALTER BOURKE,
No. 4, Mark Street, Dublin.