IMPROVED ELECTRIC_APPA- RATUS FOR COMMUNICATING BETWEEN RAILWAY STATIONS AND TRAINS, BETWEEN TRAINS, AND BETWEEN THE DIFFERENT PARTS OF TRAINS
Year: 1878

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent, for the Invention of "IMPROVED ELECTRIC_APPA-
RATUS FOR COMMUNICATING BETWEEN RAILWAY STATIONS AND TRAINS,
BETWEEN TRAINS, AND BETWEEN THE DIFFERENT PARTS OF TRAINS." A
communication from abroad by Eugène Jacques Jérôme de Baillehache, of
Paris, France.
Sealed the 29th October 1878, and dated the 1st May 1878.
PROVISIONAL SPECIFICATION left by the said William Clark at the Office
⚫of the Commissioners of Patents on the 1st May 1878.
$5
WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex, Patent
Agent.
IMPROVED ELECTRIC APPARATUS FOR COMMUNICATING BETWEEN RAIL-
WAY STATIONS AND TRAINS, BETWEEN TRAINS, AND BETWEEN THE DIFFERENT
PARTS OF TRAINS." [A communication from abroad by Eugène Jacques Jérôme
de Baillehache, of Paris, France.]
This Invention relates to improved electric apparatus for effecting communication
between railway trains, whether in motion or stationary, and stations; for com-
municating between trains on the same or different lines; and also for communicating
between the different parts of railway trains.
Hitherto all attempts at utilising electricity for the prevention of accidents on
railways have been limited to the employment of ingenious arrangements of appa-
ratus for attracting the attention of the train or station officials by the use of
semaphores, worked either mechanically or electrically, which answer well enough
for signalling at certain points, such as crossings or stations; but the object of this
Invention is to supply a want hitherto unfulfilled, the Invention consisting in
placing trains while travelling between stations, or to which any accident has
happened, in constant electric communication with the stations in front and rear,
and vice versa.

page_text: According to this Invention the guard's van or any other carriage of the train is
converted into a travelling bureau, furnished with the necessary telegraphic trans-
mitting and receiving apparatus.
In order that the Invention may be more readily understood, I will describe it
with reference to the accompanying Drawings, in which Figures 1 and 2 show
longitudinal and. transverse sections of a guard's van with the apparatus in
position.
In order to put the guard of the train in constant electrical communication with
the stations on the line without interfering with existing apparatus, the require-
ments are, 1st, a complete set of telegraph apparatus, such as in use at stations,
viz., alarum, transmitter, galvanometer, conducting wires, and battery; or to
economize space a small Bréguet apparatus may be employed, consisting of a
transmitter a, receiver b, alarum c, and a battery, preferably dry. One pole com-
municates by a copper wire with a rack rod d, operated by a pinion and crank
handle, for raising and lowering an arm e carrying a trailing spring contact plate f,
through which when lowered a continuous contact is made with a galvanised iron
wire g, herein-after termed the line wire, supported upon porcelain insulators h
disposed along the line at about 10 or 12 metres apart. These insulators are
mounted upon short posts sunk in the ground, and rising about 12 centimetres
above the level of the rails i; or the insulators may be mounted upon the sleepers
so as to prevent the ash pan of the locomotive touching the wire g. These insu-
lators may be either conical or spherical, and may be made of wood, tarred, painted,
or varnished, insulated by a tubular core of india-rubber, through which a pin
passes mounted in a forked bearing or otherwise. The other pole of the battery is
to earth through the axle guard j, the wheels, and rails. The trailing contact
follows all the indulations of the line wire g, along which it slides, being maintained
constantly in contact therewith by the weight of the rod e, which is free to play
laterally to a slight extent in its hanger k, the contact being assisted by the pressure
of a spiral spring, and, if necessary, by that of a spring l.
The trailing contact is formed of a copper plate and two thin steel spring plates
about 20 centimetres wide, and the elasticity of the largest of the two, which is
about 40 centimetres long, being increased by two spiral springs.
In order to neutralize the longitudinal, transverse, and vertical oscillations and
vibrations of the van in travelling, a system of spiral springs is placed beneath, at
the side, or at front and back of the telegraph apparatus, in order to keep the
needle of the receiving dial always in a vertical plane.
To prevent the trailing contact becoming heated the springs may, if necessary, be
kept cool by moistened cotton wicks, or by a small stream of water from a
vessel in or beneath the van, but the air alone is sufficient, owing to the speed of
the train, to keep the contact cool.
To avoid interfering with the working of junctions the line wire g is connected
at these points with the nearest station by a wire supported on telegraph posts
beside the line.
To prevent the electrical communication being interrupted at level crossings,
where the line wire g is necessarily removed from its position, and carried overhead
or otherwise for a few feet, there may be a second trailing spring contact, also raised
and lowered by a rack, the one being at the front and the other at the tail of the
train, and the two connected by a conducting wire or through the couplings, so that
when the one is passing the gap at a crossing the other is still in contact with line
wire g, and vice versa.
The line wire current at level crossings and gates may pass through a vibrating
alarum with relay, to warn the gatekeeper of the presence of a train.
The system of which the above are heads is simple, practical, inexpensive in
application, and of general utility on railways.
There is no danger of the line wire wearing, as the trailing spring contact may
be so regulated by the rack d as at any speed only just to touch the wire in passing
over the insulators. At 60 kilometres an hour contact will be made once every

page_text: half second, and it is ouly necessary to make it constant by depressing the trailing
contact by means of rack d when a message is being sent or received. The wire is.
not liable to wear even at the insulators, as it droops by its own weight, and being
free to move along the insulators the points of contact are constantly changed by
the effect of its own expansion and contraction. The wire is put in tension by
ratchet gear, such as used for ordinary wire fencing, placed so as to avoid all risk
of the trailing contact striking against any uneven surfaces.
A wire brush may be attached in front of the trailing contact to keep the wire
clear of snow in winter. The brush also adds to the number of points of contact
with the wire for the transmission of the current.
The following are further details for the transmission of messages:-
1st. When the train is in motion the ratchet should be at the stop point
indicated on the rack, in order that the trailing contact may rub with slight friction
upon the wire near the insulators.
2nd. To send a message from a train in motion to another train or to a station
the rack is raised to position No. 2, to increase the pressure of the trailing contact,
and similarly when a message is to be received.
3rd. When the travelling telegraph van is to be cut out of the circuit to allow
a message to pass to another point, or in consequence of storms, the rack should be
lowered to position No. 3, in order that the trailing contact may be raised entirely
off the wire.
4th. The train in motion always communicates directly with the arrival station,
i.c., that to which it is proceeding, provided that the instrument at the departure
station is disconnected immediately the train starts.
5th. Therefore if the guard wished to communicate with the station just left, he
would apply to the arrival station to be put in direct communication with the
departure station, which would be effected through the ordinary telegraph wire
connecting the two stations.
6th. Reciprocally, if a message is to be sent from the departure station to a train
which has just left, it would apply to the arrival station to be put in direct com-
munication with train.
7th. If the train has passed beyond station No. 2 when so applied to by station
No. 1, the call is passed on to station No. 3 in advance through the ordinary tele-
graph wire, and communication would be effected with the train through the wire
between the rails, as in the previous case.
8th. The special regulations for the working of single lines may be continued
without in any way effecting the employment of the above system for the trans-
mission of train messages; but in order to still further increase these measures of
security it is necessary that each train, although signalled by the departure to the
arrival station, on entering upon the single line should signal its approach to the
gatekeepers ahead, and also announce its presence on the line to the arrival station.
Communication being established as described in Section 2, the gatekeepers ahead
of the train would be warned by their alarums, which only cease sounding when
the train has passed them.
9th. In case of accident, or when the train has a message to send (the direction
of the current from the van being always the same as the direction of motion of the
train), the alarums of those signal boxes only which the train has not passed will
be acted on when a message is despatched.
10th. The line in front of the first signal box is not considered clear until the
vibrating alarums sounds.
11th. When a train is approaching another upon the same line, as it would be
the rule that a train should not leave a station without warning the next box in
the direction in which it is going of its approach, there is no fear of collision, as all
the trains on this same line, whatever may be their number, will receive the message
announcing the starting of the train.
Figures 3 to 13 of the Drawings are diagrams to indicate the action of the alarunts
at the gate-houses.

page_text: Figure 3 indicates that a train in connection with the line wire will set in motion
the alarums in advance of the train, and notify the arrival station. G is the
departure station; G', the arrival station; T, train; S, S, S, gate-houses alarums;
G, T, S, G', the special wire between the rails; G, G', ordinary telegraph wire.
The gatekeepers, warned by the alarums of the approach of a train, are thereby
cautioned to exercise increased vigilance.
Figure 4 indicates that after the train has passed the box the alarum ceases to
sound, those only sounding which are in front of the train, and the gatekeepers
may then with safety open the gates at the crossing for the passage of vehicles.
Figure 5 indicates that two trains on the same line may communicate. If the
stations are out of circuit the current only passes between the two trains, and when
train T¹, in ignorance of train T being on the same line, signals the station G to
which it is proceeding, its message will be received by the train T instead of by
the station.
Figure 6 shows how two trains T, T¹, may communicate where a station or signal
box intervenes by the station G¹ putting the two in direct communication by means
of the commutator C, D.
Figure 7 shows how two trains on different lines may communicate by means
of a special commutator at the arrival station; P, Paris station; M, Mantes station;
O, Oissel station; E, Elboeuf station; R, Rouen station; C, D, direct communication
by means of the ordinary telegraph; C', D¹, direct communication by means of the
ordinary telegraph and the special wire between the rails.
Suppose a train A between Paris and Mantes be travelling to Rouen, the
train A may communicate with train B travelling to Oissel from Elboeuf without
the message passing to or through a train H between Mantes and Oissel. This is
done by the station M putting the train in direct communication as far as O by the
ordinary telegraph wire, and station O does the same through C, D¹, by means of
a special commutator, as if the line current were interrupted between M and O.
Figure 8 shows how a train may communicate with a train T' in front travelling
upon the same line, or which may have broken down. In entering on the single line
G, G¹, the signal of train T to the arrival station G¹ will be received by the train T'; if
the latter by arrangement with train T puts itself out of the circuit, the train T
can communicate direct with station G¹.
Figure 9 indicates how a train broken down may communicate with the arrival
and departure stations, and also with another train approaching it. The train T
and station G' are signalled direct by the train T¹, as likewise station G, if
station G¹ puts the train T' in direct communication with G by means of the com-
mmutator above referred to.
Figure 10 shows how, if by the omission of station G to disconnect itself from
the line wire the stations G, G', are notified both at once, as well as all the crossings,
the alarums in this case only ceasing to sound when the train T arrives at G¹, and
all messages sent by train T being received by both stations.
Figure 11 indicates the case of a train T leaving the rails, and the wire being
severed. In this event those alarums which were in action at once cease to sound,
thus notifying the accident to the gatekeepers.
Figures 11a and 11b show the position of the alarums before and after the accident
respectively.
Figure 12 shows how communication is re-established after train T has left the
rails and the wire is broken. It is simply necessary to join up by a short length
of wire, either the trailing contact, or if the latter be broken, the Breguet with the
wire running along the line; thus, although the train is still off the metals, it is
easy to inform the stations before and behind of the accident by direct communi-
cation through the commutator above referred to. In this case the alarums at the
crossings will be again set in motion in the direction in which the train was
travelling (see the position of alarums, Figures 11a and 11b).
Figure 13 indicates another instance of a train having left the rails, the line
being destroyed and the wire broken. Suppose a train T to have run off the line

page_text: before reaching the points H where it should have passed on to the branch H, L,
the train T', which is started from the station G, say, ten minutes after the time
at which the train T is due at K, should be shunted at H, in order to allow the
express T travelling in the direction m, K, n, to pass, and should not pass the
point K until after the train T' has arrived at H.
In order to avoid one or more accidents in such a case, immediately the train T¹
leaves the rails, the alarums 8, 82, 81, in both directions cease working, and the gate-
keepers at once put the signals at danger. The disabled train should at once re-
connect the line wire, and by a short length of wire connected to its own apparatus
restore communication in the forward direction. There is no communication in the
backward direction unless the train T2 is already started, in which case train T
can signal the mishap to both trains travelling towards it.
To avoid interruptions at level crossings, it is preferable to employ a second
trailing contact as before mentioned, one at either end of the train, connected
together either by a wire or through the couplings, and a wire extending beneath
the carriages, as will be presently described.
The insulator supports for the line wire may be either rigid or flexible so as to
allow the wire to rise after the trailing contact has passed over it. In the latter
case the support is formed of two arms, which carry the enamelled iron spindle of
the insulator, and rests upon a bell or hood forming a protection to a sleeve or
Bocket in which works a metal spring acting stem, which rises and falls under the
pressure of the trailing contact. The support may either be fixed directly to the
sleepers by two or four ears, or fixed to posts or stakes driven into the ground at
distances of about 10 metres apart. The support is made either of cast or malleable
iron. The insulator is of wood coated with a mixture of tar and linseed oil, a steel
spring or other metallic fastening being used to confine the wire. It is effectually
insulated on the exterior by the tar and linseed oil, and on the interior with india-
rubber, gutta percha, or tar, while the stem is of enamelled iron greased. This
insulator may also be employed in other cases where a good electrical insulator is
desired. For example, when used in working the discs and points, it enables the
ordinary telegraph posts to be dispensed with, as when fixed upright in the ground
or supported horizontally on posts or stakes, allows of a current being passed
through the wire corresponding to the disc or switch for actuating an alarum, and
thus indicate that the desired operation has been performed.
In applying the Invention to railways in course of construction, instead of
employing a wire for communicating electrically between trains, or between trains
and stations, the rails may be used as conductors, the wheels of the telegraph van
being in contact with a metallic brush or a spring contact, transmit by a wire the
current to the instruments in the van. In this case the rails should be coated
throughout their length with some insulating substance, such as coal tar (preferably.
applied in a heated state) to prevent the escape of the current.
The rails may be thus employed in two ways, viz. :—
1st. Using both rails in order to close the circuit of a station at the nearest
signal box.
2nd. By employing one rail only, which allows of telegraphic communication
being established between stations in the ordinary way.
Figure 14 illustrates an example of the first case, in which two rails are
employed; X is a commutator at station A; Z, battery at station B; T, turntable;
O, branches or crossings; X, y, commutator, placing the two sides of the line or
both rails in direct communication, provision being made for such obstacles as are
presented by branches, points, crossings, and turntables, by an insulated copper wire
soldered to the rail, so that the current in ay pass uninterruptedly between the two
stations. At these points the current is diverted, the wire being carried on posts P by
ordinary insulators, and so passes round the obstacles; S, S, S, are sections of rails
to which is soldered or brazed the insulated wire for bridging over the obstacles on
the line u between station B and station A. Thus suppose two stations A, B, to
be separated by a distance of kilometres; the circuit may be closed at station A

page_text: by a commutator.
The current from station B goes to A, passes through X, y, and
returns to the battery at B; the current goes from and returns to battery Z; it is
therefore a closed metallic circuit. In this case every train travelling over this
part of the line communicates with station B and not with station A. The reverse
will be the case if station B, by means of its communicator, connects the two rails,
and if the station A puts its battery in communication with the wires connected to
the rails.
In the case of closed circuits, both rails should be completely insulated as before
described, while all interruptions or obstacles are bridged over, so to speak,
by means of a length of insulated wire carried on posts alongside, as before
described.
Figure 15 shows an example of the 2nd case, in which a single rail only is
employed for establishing communication. In this case a train travelling between
A and B may communicato with the stations by a single rail if two conducting
wires soldered to the extreme rails at each station be employed. The single rail
serves both as a means of communicating between stations, and also with a train
on any part of the line between A and B; R, R, insulated rails; E, E, fish
plates.
The escape of the current is easily avoidable at the turntables, switches, branches,
&c. For this purpose, instead of fishing the rail nearest the obstacle to be got
over, it is supported upon a chair insulated by a coating of tar; a space of a few
millimetres is also left at the end of the conducting rail, and an insulated wire is
soldered to the rail and carried alongside on posts until the obstacle is passed,
beyond which it is again connected to the line.
It is also necessary to take certain precautions with regard to the fish plates,
chairs, and bolts. The fish plates which serve to connect the rails should be
galvanised or polished on the inside for about 3 centimetres at the upper part, where
they are in contact with the rail, and should also be tarred over the whole of their
external surface. The chairs should also be tarred so as to insulate them from the
sleepers upon which they are supported. The bolt heads should likewise be coated
with hot coal tar, in order to prevent any escape of the current in to the ballast.
These precautions have the double advantage of ensuring perfect insulation and
preserving the rails, fish plates, and bolts, from oxidation.
The wire employed to bridge over the obstacles on the line should be brazed with
copper in a hole made in the rail.
The Invention thus consists in the direct transmission of telegraph messages to
trains in motion, either by means of a wire laid between the rails, or by one or
both rails, or by the use of a telephone.
The Invention is also applicable for communicating between the passengers and
guard of a train, the arrangement being such as will admit of constant electrical
communication between the guard's van and the carriages, while preventing all
tampering with the apparatus on the part of the passengers.
Figure 16 shows such an arrangement; take a train of eight carriages, for
example; the front guard's van F will be provided with a vibrating alarum S and
battery P of 10 to 12 elements which transmit the current from one carriage to the
other through the hook of the right-hand coupling chain, and thence to gutta percha
covered wires fixed within the compartments. The tail brake van F¹ is so arranged
that the wire which is in communication with the last carriage by the hook of the
coupling chain is connected with the left-hand coupling, and thus return the current
to the battery through the several left-hand couplings by means of the wire which
connects the same together. The wire may be placed at one side of the carriages, either
above or underneath the same. The hooks of the ordinary coupling chains serve in
this manner to establish a continuous current between the two poles of the battery.
The hooks at the front and rear of each carriage are connected as shown in
Figure 17, by a spiral galvanised, nickelled, or tinned wire which is free to adapt
itself to the movements of the chains, and is soldered to the hooks with copper
solder,

page_text: The alarum mechanism placed in each compartment, which is represented in
Figure 18, is operated by a crank handle to be moved from A to B, by which a
spring R is caused to press on button S so as to set in motion the alarum in the
guard's van, and which continues to sound until the handle is returned to position A.
To the handle is attached a rack rod T which protrudes from the compartment
above the door, and rotates a pinion G connected to a disc or movable lamp with
colored glasses which is projected at right angles from the side of the carriage to
indicate to the guard the compartment from whence the alarm proceeds. The
apparatus can only be reset by the guard releasing the pawl of a ratchet formed on
the pinion.
When it is desired to communicate between the front and rear brake vans F, F',
the circuit may be closed through the earth. In this case one pole of the battery
in the front brake van F, Figure 16, is connected by a wire with the axle guard,
and a similar arrangement is adopted in the rear brake van F¹.
If the Morse apparatus be in use at the stations, every train may be made to
trace its journey electrically upon the paper strip, and the time of its passage at
level crossings, as when only one apparatus is carried on the train; the current is
interrupted at such places which are thereby indicated on the paper strip. More-
over, if two trains on the same line be each provided with Morse apparatus, they
may at all times ascertain the distance they are apart.
By the foregoing arrangements,―
1st. A station may at any moment communicate with one or more trains on the
same line, whatever may be their position, and also with the stations to which they
are proceeding.
2nd. That a station may communicate with any particular train without the
others being necessarily made acquainted with the terms of the message.
3rd. That either stations or trains may warn gatekeepers of the approach of all
trains, ordinary or special.
4th. That trains may be always certain as to whether the line ahead is clear.
5th. That two or more trains travelling on the same line in the same or different
directions, may by the aid of a special commutator at their destination, be enabled
to communicate telegraphically with each other.
6th. That a train broken down may at once communicate this fact to the station
in front and rear, or to the trains travelling on the same or different lines, and also
indicate its position and any other necessary information.
7th. That the passengers in a train may communicate with the officials and the
officials with each other.
In order to more rapidly transmit messages in case of emergency, a special code
might be employed, in which every letter, according to the number of turns of the
transmitter, would represent a complete sentence..

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Clark in the Great Seal Patent Office on the 1st November
1878.
WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex, Patent
Agent. "IMPROVED ELECTRIC APPARATUS FOR COMMUNICATING BETWEEN RAIL-
WAY STATIONS AND TRAINS, BETWEEN TRAINS, AND BETWEEN THE DIFFERENT
PARTS OF TRAINS," A communication from abroad by Eugène Jacques Jérôme
de Baillehache, of Paris, France.
This Invention has in view the prevention of collisions and other accidents on
railways, and relates to improved electric apparatus for effecting communication
between railway trains (whether moving or stationary) and stations, between one
train and another on the same or a different line, and also between the passengers
and the guards or other officials of the same train.
Hitherto all attempts at utilising electricity for the prevention of accidents on
railways have been limited to the employment of ingenious arrangements of
apparatus for attracting the attention of the train or station officials by the use of
semaphores, worked either mechanically or electrically, which answer well enough
for signalling at certain points, such as crossings or stations; but the object of this
Invention is to supply a want hitherto unfulfilled; the Invention consisting in
means whereby all trains, whether travelling between stations or in distress in
consequence of an accident, are placed in constant electric communication with the
stations in front and rear, and vice versa.
According to this Invention the guard's van or any other carriage of the train is
converted into a travelling telegraphic bureau, furnished with the necessary trans-
mitting and receiving apparatus.
In order that the Invention may be more readily understood, I will describe it
with reference to the accompanying Drawings, in which Figures 1 and 2 show
longitudinal and transverse sections of a guard's van with the apparatus in
position.
In order to put the guard of the train in constant electrical communication with
the stations on the line without interfering with existing apparatus the require-
ments are, 1st, a complete set of telegraph apparatus such as in use at stations,
viz., alarum or call bell, transmitter, galvanometer, conducting wires, and battery;
or to economise space a small Bréguet apparatus may be employed, consisting of a
transmitter a, receiver b, alarum c, and a battery, preferably a dry one.
One pole
cominunicates by a copper wire with a rack rod d, operated by a pinion and crank
handle, for raising and lowering an arm e, carrying a trailing spring contact plate f
through which when lowered a continuous contact is made with a galvanised iron
wire g, herein-after termed the line wire supported upon porcelain insulators h
disposed along the road at about 10 or 12 metres apart. These insulators are
mounted upon short posts sunk in the ground and rising about 12 centimetres
above the level of the rails i; or the insulators may be mounted upon the sleepers,
or otherwise, out of the way of the ash pan of the locomotive, which must not
touch the wire g. These insulators may be either conical or spherical, and may
be made of wood, tarred, painted, or varnished, insulated by a tubular core of india-
rubber, through which a pin passes mounted in a forked bearing or otherwise.
The other pole of the battery is to earth, through the axle guard j, the wheels, and
rails. The trailing contact f follows all the undulations of the line wire g along
which it slides, being maintained constantly in contact therewith by the weight of
the rod e, which is free to play laterally to a slight extent in its hanger k, the
contact being assisted by the pressure of a spiral spring, and, if necessary, by that
of a spring l.
The trailing contact is formed of a copper plate and two thin steel spring plates
about 20 centimetres wide, and the elasticity of the largest of the two, which is
about 40 centimetres long, being increased by two spiral springs.

page_text: In order to neutralise the longitudinal, transverse, and vertical oscillations and
vibrations of the van in travelling, a system of spiral springs is placed beneath at
the side or at front and back of the telegraph apparatus, in order to keep the needle
of the receiving dial always in a vertical plane.
To prevent the trailing contact becoming heated the springs may, if necessary,
be kept cool by moistened cotton wicks or by a small stream of water from a vessel
in or beneath the van, but owing to the speed of the train the air alone is sufficient
to keep the contact cool.
To avoid interfering with the working of junctions the line wire is connected
at these points with the nearest station by a wire supported on telegraph posts
beside the road.
To prevent the electrical communication being interrupted at level crossings
where the line wire g is necessarily removed from its position and carried over-
head or otherwise for a few fect, there may be a second trailing spring contact.also
raised and lowered by a rack, the first one being at the front and the other at the
tail of the train, and the two connected by a conducting wire or through the
couplings, so that when the one is passing the gap at a crossing the other is still in
contact with line wire g, and vice versa.
The line wire current at level crossings and gates may pass through a vibrating
alarum with relay to warn the gatekeeper of the presence of a train.
The system of which the above are heads is simple, practical, inexpensive in
application, and of general utility on railways.
There is no danger of the line wire wearing, as the trailing spring contact may
be so regulated by the rack d as at any speed only just to touch the wire in passing
over the insulators. At 60 kilometres an hour contact will be made once every
half second, and it is only necessary to make it constant by depressing the trailing
contact by means of rack d when a message is being sent or received. The wire is
not liable to wear even at the insulators as it droops by its own weight, and being
free to move along the insulators the points of contact are constantly changed by
the effect of its own expansion and contraction. The wire is put in tension by a
wire stretcher in form of a ratchet, such as used for ordinary wire fencing, placed
so as to avoid all risk of the trailing contact striking against any uneven surfaces.
A wire brush may be attached in front of the trailing contact to keep the wire
clear of snow in winter; the brush also adds to the number of points of contact
with the wire for the transmission of the current.
The following are rules to be observed in the transmission of messages:-
1st. When the train is in motion the pinion should be opposite a certain mark
nade on the rack, in order that the trailing contact may rub with slight friction
upon the wire near the insulators.
2nd. To send a message from a train in motion to another train or to a station
the rack should be raised to position No. 2, to increase the pressure of the trailing
contact, and similarly when a message is to be received.
3rd. When the travelling telegraph van is to be cut out of the circuit to allow a
message to pass to another point, or when in consequence of thunderstorms the
apparatus at the stations are not in working order, the rack should be lowered to
position No. 3, in order that the trailing contact may be raised entirely off the wire.
4th. The train in motion always communicates directly with the station to which
it is proceeding, the instrument at the station in rear having been disconnected
immediately the train started.
5th. Therefore, if the guard wished to communicate with the last station quitted
he would apply to the station ahead to be put in direct communication with the
station in rear, which would be effected through the ordinary telegraph wire con-
necting the two stations.
6th. Reciprocally if a message is to be sent from a station to a train which has
left it, application would have to be made to the next station to be put in direct
communication with train.
7th. If the train has passed beyond station No. 2, when so applied to by station

page_text: No. 1, the call is passed on to station No. 3 in advance through the ordinary
telegraph wire, and communication would be effected with the train through the
wire between the rails, as in the previous case.
8th. The special regulations for the working of single lines may be continued in
use without in any way affecting the employment of the above system for the
transmission of train messages, but in order to still further increase these measures
of security, it is necessary that each train, although signalled by the station which
it has left, to the station to which it is proceeding, on entering upon the single line,
should signal its approach to the gatekeepers ahead, and also announce its presence
on the line to the station ahead. Communication being established as described in
§ 2, the gatekeepers ahead of the train would be warned by their alarums, which
only cease sounding when the train has passed them.
9th. In case of accident, or when the train has a message to send (the direction of
the current from the van being always the same as the direction of motion of the
train); the alarums of those signal boxes only which the train has not passed will
be sounded when a message is despatched.
10th. The line in front of the first signal box is not considered clear until the
vibrating alarum sounds.
11th. No train should leave a station without warning the next box in the
direction in which it is going of its approach, so that when one train is approaching
another on the same line, there shall be no danger of collision, as all the trains on
the same line, whatever may be their number, will receive the message announcing
the starting of the train.
Figures 3 to 13 of the Drawings are diagrams to indicate the action of the alarums
at the gatehouses.
Figure 3 indicates that a train in connection with the line wire travelling from
station G to station G', will set in motion the alarums in advance of the train, and
notify the station G¹; T, train; S, S, S, gatehouse alarums; G, T, S, G¹, the
special wire between the rails; G, G₁, ordinary telegraph wire. The gatekeepers
being warned by the alarums of the approach of a train, are thereby cautioned to
exercise increased vigilance.
Figure 4 indicates that after the train has passed the box, the alarum ceases to
sound, those only sounding which are in front of the train, and the gatekeepers
may then with safety open the gates at the crossing for the passage of vehicles.
Figure 5 indicates that two trains on the same line may communicate electrically.
If the stations are out of circuit, the current only passes between the two trains,
and when the guard of train T', in ignorance of train T being on the same line,
signals the station G to which he is proceeding, the message will be received at the
train T instead of at the station.
Figure 6 shows how two trains T, T¹, may communicate, where a station or signal
box intervenes, by the two being put in direct communication by means of the
commutator C, D, at the station or signal box.
Figure 7 shows how two trains on different lines may communicate by means of
a special commutator at the station towards which they are proceeding. Let P be
Paris station; M, Mantes station; O, Oissel station; E, Elboeuf station; R, Rouen
station; C, D, direct communication by means of the ordinary telegraph; C', D',
direct communication by means of the ordinary telegraph and the special wire
between the rails.
Suppose a train A between Paris and Mantes be travelling to Rouen. The train
A may communicate with train B, travelling to Oissel from Elboeuf without the
message passing to and through a train H between Mantes and Oissel. This is
done by the station M putting the train in direct communication as far as O by the
ordinary telegraph wire, and station O does the same through C', D₁, by means of a
special commutator as if the line current were interrupted between M and O.
Figure 8 shows how a train may communicate with a train T¹ in front, travelling
upon the same line, or which may have broken down. In entering on the straight

page_text: line G, G¹, the signal of train T to the station G¹, will be received by the train T';
if the latter by concert with train T puts itself out of the circuit, the train T can
communicate direct with station G¹.
Figure 9 indicates how a train broken down or in distress may communicate
with the stations in front and rear, and also with another train approaching it.
The train T and station G¹ are signalled direct by the train T, and likewise station
G, if station G¹ puts the train T¹ in direct communication with G by means of the
commutator above referred to.
Figure 10 shows how, if by the omission of station G to disconnect itself from
the line wire, the stations G, G₁, are both notified as well as all the crossings, the
alarums in this case only ceasing to sound when the train T arrives at G¹, and all
messages sent by train T being received by both stations.
Figure 11 indicates the case of a train T leaving the rails and the wire being
severed. In this event, those alarums which were in action at once cease to sound,
whereby coupled with the non-arrival of the train, the gatekeepers are warned of
the accident.
Figures 11a and 11 show the position of the alarums before and after the
accident respectively.
Figure 12 shows how communication is re-established after train T has left the
rails and broken the wire. It is simply necessary to join up by a short length of
wire, either the trailing contact, or if the latter be broken, the Breguet instrument
with the line wire. Thus, although the train is still off the metals, it is easy to
inform the stations, before and behind, of the accident by direct communication
through the commutator above referred to. In this case, the alarums at the
crossings ahead of the train will be again set in motion (see the position of alarums,
Figures 11 and 11b).
Figure 13 illustrates another instance of a train having left the rails, torn up the
line, and broken the wire. Suppose the train T to have run off the line before
reaching the points H where it should lave passed on to the branch H, L, the
train T which is started from the station G₁, say ten minutes after the time at
which the train T is duo at K, should be shunted at H in order to allow the
express T2 travelling in the direction m, K, n, to pass, and should not pass the
point K until after the train T¹ has arrived at H.
In order to avoid one or more accidents in such a case, immediately the train T¹
leaves the rails, the alarums 8, 82, 81, in both directions cease working, and the gate
keepers at once put the signals at danger. The disabled train should at once
reconnect the line wire, and by a short length of wire connected to its own apparatus
restore communication in the direction of the station ahead. There is no communi-
cation in the backward direction unless the train T is already started, in which case
train T can signal the mishap to both trains travelling towards it.
To avoid interruptions at level crossings it is preferable to employ a second
trailing contact as before mentioned, one at each end of the train connected together
either by a wire or through the couplings, and a wire extending beneath the
carriages, so that when the one contact is passing over the gap in the line wire
occasioned by the level crossing the other contact is touching the wire, as will be
presently described.
The insulator supports for the line wire may be either rigid or flexible, so as to
allow the wire to rise after the trailing contact has passed over it. In the latter
case the support is formed of two arms, which carry the enamelled iron spindle of
the insulator, and rests upon a bell or hood forming a protection to a sleeve or
socket in which works a metal rod pressing on a spring, which acts upwards or
downwards and rising and falling under the pressure of the trailing contact. The
support may either be fixed directly to the sleepers by two or four ears, or fixed to
posts or stakes driven into the ground at distances of about 10 metres apart. The
support is made either of cast or malleable iron. The insulator is of wood coated
with a mixture of tar and linseed oil (a steel spring or other metallic fastening

page_text: being used to confine the wire), and it is effectually insulated on the exterior by the
tar and linseed oil, and on the interior with india-rubber, gutta percha, or tar, the
spindle being of enamelled iron and greased. This insulator may also be employed
in other cases where a good electrical insulator is desired; for example, in working
signals and points it enables the ordinary telegraph posts to be dispensed with, as
when fixed upright in the ground or supported horizontally on posts or stakes, it
allows of a current being passed through the wire corresponding to the disc or
switch for actuating an alarum, and thus indicate that the desired operation has
been performed.
In applying the Invention to railways in course of construction, instead of
employing a wire for communicating electrically between trains or between trains
and stations, the rails may be used as conductors, the wheels of the telegraph van
being in contact with a metallic brush or a spring contact in order to transmit by a
wire the current to the instruments in the van. In this case the rails should be
coated throughout their length with some insulating material, such as coal tar
(preferably applied in a heated state), to prevent the escape of the current.
The rails may be thus employed in two ways, viz.,
1st. Using both rails in order to close the circuit of a station at the nearest
signal box:
2nd. By employing one rail only, which allows of telegraphic communication
being established between stations in the ordinary way.
Figure 14 illustrates an example of the first case, in which two rails are employed.
✗ is a commutator at station A; Z, battery at station B; T, turntable; O, branches
or crossings; x, y, commutator placing the two sides of the line or both rails in
direct communication, provision being made for such obstacles as are presented by
branches, points, crossings, and turntables by an insulated copper wire soldered to
the rail, so that the current may pass uninterruptedly between the two stations.
At these points the current is diverted, the wire being carried on posts P by ordinary
insulators, and so avoids the obstacle or interruption. S, S, S, are sections of rails, to
which is soldered or brazed the insulated wire for avoiding or bridging over the
obstacles or interruptions on the line n between station B and station A. Thus
suppose two stations A, B, to be separated by a distance of n kilometres, the
circuit may be closed at station A by a commutator. The current from station B
goes to A, passes through X, y, and returns to the battery at B; the current goes
from and returns to battery Z, and the circuit is therefore a closed metallic one. In
this case every train travelling over this part of the line communicates with
station B, and not with station A. The reverse will be the case if station B, by
means of its commutator, connects the two rails, and if the station A puts its
battery in communication with the wires connected to the rails.
In the case of closed circuits both rails should be completely insulated, as before
described, while all interruptions or obstacles are bridged over, so to speak, by
means of a length of insulated wire carried on posts alongside, as before described.
Figure 15 shews an example of the second case in which a single rail only is
employed for establishing communication. In this case a train travelling between
A and B may communicate with the stations by a single rail, two conducting wires
soldered to the rail being led to each station. The single rail serves both as a means
of communicating between stations, and also with a train on any part of the line
between A and B. R, R, insulated rails; E, E, fish plates.
4
The escape of the current is easily avoidable at the turntables, switches, branches,
&c. For this purpose instead of fishing the rail nearest the obstacle or interruption 5
to be got over, it is supported upon a chair insulated by a coating of tar; a space of
a few millimetres is also left at the end of the conducting rail, and an insulated wire
is soldered to the rail and carried alongside on posts until the obstacle is passed,
beyond which it is again connected to the line.
It is also necessary to take certain precautions with regard to the fish plates, 5
chairs, and bolts. The fish plates which serve to connect the rails should be

page_text: galvanised or polished on the inside for about three centimetres at the upper part where
they are in contact with the rail, and should also be tarred over the whole of their
external surface. The chairs should also be tarred, so as to insulate them from the
sleepers upon which they are supported. The bolt heads should likewise be coated
with hot coal tar, so as to prevent any escape of the current into the ballast. These
precautions have the double advantage of ensuring perfect insulation and preserving
the rails, fish plates, and bolts from oxidation.
The wire employed to bridge over the obstacles on the line should be soldered
with copper in a hole made in the rail.
The two arrangements last described thus have for their object to substitute in
the case of new lines the rail itself for the line wire between the rails as a means of
establishing direct telegraphic communication between trains or between trains and
stations. In this novel mode of transmission the essential point is to ensure the
perfect insulation of the rail by coating it with tar applied in a heated state to
render the circuit continuous through the medium of the fish plates, and to bridge
over the obstacles or interruptions caused by turntables, points, and branches by
means of wires connecting the rails at either side of the obstacle.
The Invention thus enables the direct transmission of telegraph messages to trains
in motion, either by means of a wire laid between the rails or by one or both rails;
or by the use of a telephone.
The Invention is also applicable for communicating between the passengers and
guard of a train, the arrangement being such as to admit of constant electrical
communication between the guard's van and the carriages, and prevent the passen-
gers tampering with the apparatus with impunity.
Figure 16 shews such an arrangement. Take a train of eight carriages for example,
the front guard's van F will be provided with a vibrating alarum S and battery P
of ten to 12 elements, which transmits the current from one carriage to the other
through the hook of the right-hand coupling chain, and thence to gutta percha
covered wires fixed within the compartments. The tail brake van F¹ is so arranged
that the wire which is in communication with the last carriage by the hook of the
coupling chain is connected with the left-hand "coupling, and thus returns the current
to the battery through the left-hand couplings by means of the wire which connects
them. The wire may be placed at one side of the carriages, either above or underneath.
The hooks of the ordinary coupling chains thus serve to establish a continuous
circuit between the two poles of the battery. The hooks at the front and rear of
each carriage are connected, as shewn in Figure 17, by a galvanized, nickelled, or
tinned spiral wire, which is free to adapt itself to the movements of the chains, and
is soldered to the hooks with copper solder.
The alarum mechanism placed in each compartment, which is represented in
Figure 18, is operated by a crank handle to be moved from A to B, by which a
spring is caused to pass on button S, so as to set in motion the alarum in the
guard's van, which continues to sound until the handle is returned to position A.
To the handle is attached a rack rod T, which protrudes from the compartment
above the door, and rotates a pinion G connected to a disc or moveable lamp with
colored glasses, which is projected at right angles from the side of the carriage to
indicate to the guard the compartment from whence the alarm proceeds.
apparatus can only be reset by the guard releasing a pawl from a ratchet formed
on the pinion.
The
When it is desired to communicate between the front and rear brake vans F, F',
the circuit may be closed through the earth. In this case one pole of the battery
in the front brake van F, Figure 16, is connected by a wire with the axle guard,
and a similar arrangement is adopted in the rear brake van F¹.
If the Morse apparatus be in use at the stations every train may be made to
record electrically upon the paper strip its journey, and the time of its passage at
level crossings, as when only one apparatus is carried on the train the current is,
interrupted at such places, which are thereby indicated on the paper strip. More-

page_text: over, if two trains on the same line be each provided with Morse apparatus they
may at all times ascertain the distance they are apart.
By the foregoing arrangements,—
1st. A station may at any moment communicate with one or more trains on the
same line, whatever may be their position or the direction in which they are travel-
ling, and also with the stations to which they are proceeding.
2nd. That a station may communicate with any particular train without the
others being necessarily made acquainted with the terms of the message.
3rd. Both stations and trains may warn gatekeepers of the approach of all
trains, ordinary or special.
4th. Trains may be always certain as to whether the line ahead is clear.
5th. Two or more trains travelling on the same line in the same or different
directions, may, by the aid of a special commutator at their destination communicate
telegraphically with each other.
6th. A train disabled may at once communicate this fact to the station in front
and rear, or to the trains travelling on the same or different lines, and also indicate
its position and other necessary information.
7th. The passengers in a train may-communicate with the officials, and the
officials with each other.
In order to more rapidly transmit messages in cases of emergency a special code
might be employed, in which every letter, according to the number of turns of the
transmitter, would represent a complete sentence.
In describing this improved system of establishing permanent electrical commu-
nication between railway trains and stations it has been shewn that messages may
be transmitted telegraphically whatever may be the position of the wire, and to
avoid the objections to a wire laid between the rails it is preferable to place it along-
side the railroad or above the roofs of the carriages.
The following details will enable companies to employ the various telegraphic
instruments, including the telephone and microphone, in connection with this
Invention.
Referring to Figure 19 the contact piece consists of a metallic plate a, upon
which are fixed two or more spring plates b fixed at one end to the plate a. The
springs are made of steel, partly covered with copper, which strengthens them
without lessening their elasticity. In practice they would be made of about 10
inches in width, and from 12 to 16 inches in length. The free ends of the springs
are fitted to work between two small cylindrical pins, and they are retained at their
under part beneath the plate by another copper plate provided with binding studs,
to which is attached the wire connected to the instruments in the guard's van. The
spring contact a projects at the side of the van, being supported by an arm having
one or two branches resting on a friction roller h to allow of its free oscillation
within the limits allowed to it by the stop i. j, k, are two steel springs, applying
a slight pressure in opposite directions to arm g. The weight of the spring contact
a is counterbalanced by a weight l. m is a bracket inside the van, upon which
the weight is placed when the apparatus is to be disconnected, the spring contact
then descending by its own weight.
On the inner end of the arm g is a binding stud n, to which the wire of the
receiving instrument is attached, the said instrument being to earth through the
axle guard as before mentioned.
The above arrangements are susceptible of considerable variation to suit the
circumstances of each line, the principle remaining however the same in all cases.
The movement of the contact piece a, b, which may be compared to that of a
balance having been indicated I will describe the arrangements required to ensure
proper contact with the wire.
As the distance between the telegraph poles on railways varies, and the wires
are in some cases carried underground, the arrangements to be adopted can only be
indicated in a general way, as they depend on the rolling stock of each company,
the number of tunnels, &c.

page_text: It is, however, always possible to fix the posts at distances of from two to four
metres apart, and at the proper distance from the rails, and they may be strengthened
by struts or placed closer together on curves if necessary. Posts should be erected
where they are not already fixed, upon which should be mounted, at a few inches
above the level of the contact piece, an arm of metal or wood forming a support for
an insulator, by which the line wire is supported alongside of the line. This wire
is placed about on a level with the contact piece, as shown in Figuro 20, so as to
constantly press by its own weight thereon, the pressure diminishing gradually as
the contact piece approaches the insulators.
The springs of the contact piece should never rise high enough to strike the hook
which supports the wire, care being taken however that when one of the spring
plates leaves the wire at the moment of passing the insulator (see Figure 20), the
other plate shall be still in contact, and thus prevent any interruption of the
current. Moreover, a number of these spring contacts may be arranged along the
side of the carriage to ensure a more perfect contact. Interruptions will sometimes
occur at level crossings owing to the necessity of carrying the wire up to a con-
siderable height to allow of the passage under it of carts loaded with hay, for
example. An uninterrupted communication may however be had if desired by
means of a second contact on one of the passenger carriages or on the rear guard's
van placed in electrical communication with the first one at the front part of the
train by the arrangement before mentioned in .connection with the hook of the
safety coupling chain, whether the said hooks are brazed or whether a wire be
simply rivetted thereto above the line of traction.
The same arrangements are adopted at branches and junctions as at level
crossings except as regards the two outside lines where the line wire may be con-
tinued alongside without inconvenience. In tunnels the insulators would be
attached to the walls, the wire being kept at the same level as before. At curves
the posts should be placed closer together, and the insulators at a height depending
on the cant of the line, and on whether the line wire is placed on the inner or outer
side of the curve.
There will be no difficulty in providing the telegraphic communication in the
station itself, as the insulators and their supports would be at a sufficient height
and distance to avoid the carriage doors and goods cargoes.
It will be casily seen that this contact arrangement will not only enable tele-
graphic communication to be had between trains in motion, but also render possible
the use of the telephone and microphone for the purpose, owing to the perfect
contact obtained; padded carriages would be employed in this case on account of
the sound, and the earth wire would pass by way of the axle guards.
There is no doubt also that an ordinary dial telegraph, or Morse, or other
apparatus might also be used to indicate the position of trains to the station master
or gatekeeper.
If a dial telegraph is used (Figure 24) every other letter, A, C, E, G, I, &c.,
would indicate a contact, and the alternate letters B, D, F, H, &c., an interruption
or the passage of a train over a level crossing. When a Morse apparatus is used
the transit of trains would be indicated by the variations in the marks on the strip
As the
consequent on the contact and interruptions in the contact of the pallet.
wire is throughout laid parallel to the train, and in contact with the contact pallet,
the breadth of the latter (10 inches) is such that it shall always remain in contact
with the wire, while its height, arrangement, and form are calculated with a view
to compensate for the slightest differences in level caused by the vibration or
oscillation of trains or other causes apt to produce interruptions.
The wire stretchers need only be placed at distances of one kilometer apart, or, if
necessary, additional posts may be employed to lessen the sagging due to the weight
of the wire.
Figure 19 is a section of a van with the apparatus applied.
Figure 20 is an ordinary telegraph post with an arm, from which the wire is

page_text: Figures 21, 22, and 23 show respectively side and front view and plan of one
of the pallets or contact plates.
Figure 24 is a view of a railway with the wire for communicating between trains
in motion and stations; this Figure also shows the mode of using a dial telegraph
at a station for the purpose of indicating the position of a train in communication
therewith.
The
The letters A, C, E, G indicate those sections of the line where contact is made;
and letters B, D, F, other points of the same line where interruptions occur.
same letters A, B, C, D, &c., on the dial correspond with the passage of a train
at these points as the needle on the dial moves one notch every time a contact is
made and broken.
The position of the train is indicated in the figure by the pallet at G; the needle
on the dial also standing opposite this letter, and in this manner the progress of the
train may be followed or ascertained at any moment.
Figure 25 shows a larger view of the dial.
a, Figure 21, is the plate upon which the contact springs b, b, are fixed at c, c; d, d,
Blots in plate a, through which the ends of springs b pass, and are retained by copper
or other metallic strips e, attached to the lower edge of each spring; the wires f
are attached to these strips; e', copper strips for strengthening the upper portion of
the springs.
9, Figure 19, arm on which the contact springs are supported; h, friction
roller; i, stop for limiting the upward motion of arm 9; j, k, springs of equal
strength pressing on opposite sides of the arm g, the one being fixed on the inside
and the other on the outside of the van; L, weight suspended from the inner end
of arm g, to counterbalance the pallet; m, bracket, upon which the weight is placed
when the apparatus is not in use; n, stud on end of arm g; o, wire connecting the
instrument in the van with the contact pallet; p, earth wire connecting with the
axle guard of one of the wheels; q, insulator.
r, Figure 20, suspension hook for line wire.
I will next describe the method of giving a graphical representation of the
position of trains on the several sections of a railway. The ruling principle of the
block system is that a train shall not be allowed to enter upon a section until the
preceding train has reached the next station; notwithstanding these precautions
however accidents still continue to occur. The line being in fact signalled "clear,"
as soon as the train arrives at the station, should any delay occur in restarting the
train, the following one may run into it. A very simple modification would,
however, render the block system absolutely safe. If a permanent contact in con-
nection with the train itself be established on a line divided into n sections, contact
would be maintained during the whole time the section is being traversed, and the
line would therefore never be signalled "clear," either too soon or too late. Thus
the safety of the passengers is not made entirely dependant on the vigilance of the
signalman, who may, perhaps, have several switches to attend to at different points,
may be liable to err or to have his attention diverted.
The arrangement, which, to be adopted by preference for insuring a permanent
contact while the train is traversing a section, is very simple, as the wire is by its
own weight caused to remain in constant contact with a second pallet placed about
one foot above the first on the side of the front van. It will be easy by means of
this second pallet to ascertain the progress and speed of trains travelling on the
different sections of the line, and also the exact time occupied.
Referring to Figure 26, suppose a line A, B, to be divided into sections a c, cd,
de, ef, fb, and that at each point c, d, e, f, an insulated metal wire is connected,
so as to establish communication between trains travelling on the line and a
station Z, where are received the series of indications transmitted by the palicts of
trains P, P. In this manner an electric circuit closed by the earth is established
between each train and station Z, where are combined elements forming separate
batteries. As however a number of separate wires would seriously interfere with
the working of a railway, this difficulty may be avoided by combining the whole of

page_text: the wires between A and B in the form of a cable, composed in the present instance
of five insulated wires intersected at the several points c, d, e, f, B. The cable is
thus of equal strength throughout, but the electric current will pass through one
wire only at a time.
The cable is supported by a ring hung from the post carrying the insulator and
wire of the second contact pallet, and is to be kept in suitable tension. Each wire
corresponding with the needle of a receiver, whose mechanism is similar to that
used for working the needle of dial receivers; it will thus be seen that the several
zones or sections of line traversed by the trains may be all controlled from one
centre, as the several needles will in turn be set in motion by the trains themselves
through the medium of the cable connected with the said station. This system
may be further extended by making the needle of one section indicate breaks or
interruptions, may have regular distances in a section, as for instance, the distance of
the several telegraph poles. Thus at each post, or at, say, every one hundred yards,a
series of contacts and breaks might be produced which would operate the corresponding
receiver and convey information of a train having met with a mishap at any point
even before the guard would have had time to make arrangements for the purpose.
A vibrating alarm, or a dial receiver with relay, if the current is too weak on
account of the distance, should be placed at each intersection, in order to avoid any
failure in the action by which a train might be allowed to enter on a section before
it is clear. It would be left to the option of the railway companies to employ such
instruments as may be judged most suited for the purpose.
The chief point in view is to demonstrate the practical possibility of controlling
the movements of trains by tracking them throughout their journey and recording
their speed time of passing any given points, delays, or excessive speeds, at distances
which have been hitherto considered impossible.
In place of using a system of needles operated by electro-magnets, a Morse
cylinder may be employed to record the journey of the trains by means of as many
needles and electro-magnets as there are wires corresponding to as many sections of
the line.
Another modification in the apparatus for transmitting messages to and from
trains in motion is illustrated in Figures 29 and 30. In this case a roller is sub-
stituted for the contact pallet before described. By means of such an apparatus,
rendered free to adopt itself to every movement of the telegraph wire without ever
ceasing to remain in contact with it while the train is in motion, the perfect contact
ensured by the pressure of the wire upon the roller will enable the current passing
through the wire to pass to earth through a receiving instrument in which messages
are received as regularly as at a station, the speed of the train, however great, being
as nothing compared with that of the current.
The above arrangement possesses the advantages of being simple, practical, and
easy of application; it requires no attention when once installed, and affords perfect
security in the working of trains.
c is one of the insulators hung on a pin in a fork b from an arm a parallel to the
line, so as to avoid any risk of the carriages striking against it.
The line wire e is suspended from the insulators c by a wire and ring or spring
hook d, the wire being maintained at the proper tension by means of compensation
tightening devices, such as are at present in use, which allow of expansion and con-
traction, placed at distances 500 or 1000 yards apart.
Upon the side of the guard's van, preferably above the doorway, is mounted a
copper roller f, flanged to prevent the wire from slipping off. An oil cup g is placed
at each end of the roller f, which is supported on friction rollers h, Figure 28,
disposed around the spindle i. Such spindle is supported at each end on two round
rods j, j, capable of vertical adjustment for regulating the action of the apparatus.
The arms are parallel to and equidistant from a rod k, connected at its lower end
to a lever l, slightly curved at the end, and having a rounded edge, whereby the
rods are enabled to slide up and down with slight friction in their guides, which are
fixed to the van. The lever is pivoted at m on a fixed support, and has a sliding
B

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weight n on its other end, which may be fixed in any position by a locking lever o.
The end of the wire to the receiving instrument is coiled in the form of a spring p
upon a stem forming a prolongation of the spindle i, and retained thereon by a
collar and by a pin terminating in a copper knob. This knob in revolving makes con-
tact with a tongue 8 of the same metal, supported by a steel spring, which is pressed
against one of the supporting arms of the cylinder by means of bolts and insulating
strips of india-rubber. By this means the speed at which the cylinder f rotates
may be readily indicated, from which can be calculated the speed of the train, as
at every revolution of the cylinder the knol strikes the tongue 8, and transınits to
an electro-magnet provided with a needle, and actuated by the local battery in the
van, the rotatory movement of the cylinder, that is to say, the contacts and inter-
ruptions caused by the rotation of the knob on the spindle.
The other arrangements in the van remain the same as before as regards the
suspension of the telegraph apparatus upon balancing springs, and the connection
of the earth wire to the axle guard, and thence to earth through the wheels and
rail.
Two rollers and levers may be mounted upon each guard's van, as in Figure 29,
so as to avoid striking the insulator. A second wire e¹, Figure 30, of a few yards
in length, and attached to the wire e at each end, may also be employed at each
point of suspension, said wire e¹ passing below the insulators. It may be objected
that the contact will cease for a fraction of a second, but this will be obviated by
employing two rollers on each van, as in Figure 30, instead of one, so that when
the first roller ceases contact at the point of suspension the second roller at the
other end of the van will be still in contact with the wire. It should be added that
vertical slots are made in the side of the guard's van, lined with stout india-rubber
to allow of the play of the roller, and also to avoid shocks consequent on any
sudden variation of speed.
In the arrangements in which contact is obtained by the wire bearing upon the
contact roller pallet, brush, or other device, instead of by the latter pressing on the
wire, the difficulty arising from the motion of the train is avoided. The weight of
the wire ensures a permanent contact, whatever may be the movements of the
carriage, when two roller pallets or other devices are employed, although one may
momentarily lose contact with the wire.
The receiver or transmitter might also be a telephone, it being simply necessary
to connect the line with the two contact screws and close the circuit through the
earth.
The arrangement considered the most practical consists in placing the contact
roller upon the roof the guard's van, with freedom to rise and fall to the extent of
from 12 to 16 inches in its guides, which might in this case be fixed in the
small look-out cab which usually projects above the roof. The weighted lever would
be on the inside and the contact roller be above the roof.
With this arrangement the wire would be supported of a height of from 14
feet 8 inches to 14 feet 10 inches above the level of the rails at the centre of
the line for carriages of the type in use on the Western Railway of France.
The load gauge for goods cargoes being 14 feet, and the height of bridges and
other standing works being 15 feet 9 inches in the clear, the contact roller, although
beyond the load guage, will not be liable to come in contact with the bridges, &c.,
while it has sufficient vertical play to let it pass inside the load guage.
A certain amount of elasticity may also be imparted to the line wire at its point
of suspension from the insulators by coiling it in spiral form and passing it through
a ring to bring the two ends into a plane perpendicular to the line, as represented
in Figure 31, in which indicates the point of attachment of the wire to the
insulator c; b, the forked steun by which the insulator is attached to the arm of
the telegraph pole; v, spiral part of wire; t, ring through which the wire passes;
f, contact roller. This arrangement avoids any obstruction to the roller at this
point....
Having now described the Invention, and the manner of performing the same, I

page_text: declare that what I claim as the Invention to be protected by the herein-before in
part recited Letters Patent is, the various arrangements of electric circuits and
apparatus arranged, applied, and operating, substantially as and for the purpose
herein shewn and described.
In witness whereof, I, the said William Clark, have hereunto set my hand
and seal, this Thirty-first day of October, in the year of our Lord One
thousand eight hundred and seventy-eight.
W CLARK, (18.)