IMPROVEMENTS IN APPARATUS USED IN TRAIN SIGNALLING ON RAILWAYS
Year: 1865

page_text: LETTERS PATENT to Edward Tyer, of No. 15, Old Jewry Chambers, in
the City of London, for the Invention of "IMPROVEMENTS IN APPARATUS
USED IN TRAIN SIGNALLING ON RAILWAYS."
FROVISIONAL SPECIFICATION left by the said Edward Tyer at the Office
of the Commissioners of Patents, with his Petition, on the 6th January
1865.
I
I, EDWARD TYER, of No. 15, Old Jewry Chambers, in the City of London,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
APPARATUS USED IN TRAIN SIGNALLING ON RAILWAYS," to be as follows:-
This Invention has for its object improvements in apparatus used in train
signalling on railways.
Hitherto in signalling trains by means of the "step-by-step" or dial
telegraph, very great uncertainty has been found to exist from what is
technically known as "tripping" and this is caused in numerous instances by
the transmitting key used by the signalman being worked at too great a speed,
causing the distant instrument to "trip" or lag behind, and thereby exhibit one
particular signal at a station, and quite a different one at another station. At
other times the "tripping" has been caused by bad contact, especially where
alternately reversed currents have been employed, the requisite time for the
efficient working of the instrument not having been allowed for in the con-
siruction of the transmitting key, the electric currents being sent faster than
the mechanical arrangements can keep pace with. Now in order to avoid

page_text: these irregularities I arrange my instruments in pairs in such manner that if
it is required to transmit two or more currents along the same wire in the
same direction, the indication on the dial will only record "one" signal, and
this arrangement has the further advantage that after the signalman has
forwarded one signal, which appears on the dial of the distant instrument, he
can transmit two, three, or more intimations generally known as bell or gong
call signals, in rapid succession, without altering in any way the previous
signal exhibited on the dial plate of the distant instrument. For this purpose
I so connect up the instruments that "copper" currents are sent from one
station, causing the dial instruments both at the sending and receiving stations
to move one step, and "zinc" currents are forwarded from the distant station,
thereby causing the dials of both instruments to move the second step, and so
on, first "
copper current and then zinc current in regular and alternate
succession, the currents originating alternately at the two stations. By this
method very great regularity is obtained, and the instruments work in perfect
unison without tripping.
"
In the Specification of a Patent granted to me, and dated November 29th
1861 (No. 3015), I have explained several plans for converting the oscillatory
movement of the electro-magnetic apparatus into a rotary movement of a
wheel and axle, carrying an index or hand pointing in succession to the
letters of the alphabet or other signs engraved on a fixed dial plate. Now,
while either of these arrangements are applicable for giving the required
movement to the index of the dial, yet I prefer to construct my instruments
with a moveable disc revolving behind a fixed screen, and dividing this disc
into six equal parts, I also cut an opening in the fixed screen equal in extent
to one-sixth of the revolving disc, so that only one portion is visible at a time.
On the disc I prefer to engrave the following signals:-1st, "train ready;"
2nd, "train may leave;" 3rd, "train left;" 4th, "all right; " 5th, "line
blocked;" and, 6th, "line clear." The 1st and 3rd signals are painted or
engraved black on a white ground; the 2nd, 4th, and 6th, white letters on a
pale green ground, and the 5th, white letters on a red ground.
As soon as the 5th signal is exhibited on the dial plate the revolution of the
wheel and axle carrying the revolving disc is so constructed as to raise a small
semaphore signal on the upper portion of the dial plate, and this small
semaphore remains raised until the 6th
when it instantly drops to its normal
transmitting key is simply a "plunger," the piston rod of which is tipped with
ebonite at one extremity, and upon being forced down by the hand of the
operator the "tip" pushes away a spring, to which is screwed the line wire,
signal of "line clear" is received,
position. The arrangement of the

page_text: and this spring upon being further depressed comes into contact with certain
connections of the battery and earth, and allowing the current to flow to the
distant station causes the disc to revolve one step, and after having so caused
the disc to revolve one step he can send any desired number of bell or gong
call signals without altering the position of the disc. The distant station is
filted up with a similar instrument, but the battery connections are reversed,
so that whilst the first instrument forwards only "copper" currents, the second
instrument sends "zinc" currents, causing the disc of both instruments to
revolve the second step, and thus by the alternate transmission of copper and
zinc currents the disc of each instrument revolves, and the signals appear in
succession through the opening in the fixed screen.
I would here remark that step-by-step instruments having other arrange-
ments or codes of signals to those above described may also be worked in pairs
by reversed currents, in the manner above described.
Another part of my Invention relates to an improved arrangement of
permanent magnets in connection with clectro-magnets for the purpose of
giving angular motion to the needles, hands, or pointers of telegraph instru-
ments, and consists of employing two permanently magnetic rings, fixed end
to end on the same axle, something like the figure 8; these rings have an
opening or notch made in each, about half-way through, and two very fine
saw cuts through the remaining metal, thereby separating the ring, but with
the poles almost in contact. The horns" of the electro-magnetic coil or
coils are formed to fit into these openings, allowing just sufficient space for
the amount of oscillation required. By this arrangement the permanent
magnetic force is concentrated at the openings near the fine saw cuts, and
the full effect of the electro-magnetic attractive and repulsive influence is
obtained.
I apply this arrangement to work the pallets of the step-by-step telegraph
previously described to give angular motion to the "needles" or "indices" of
train signalling telegraphs to work "relays " to move discs behind fixed screens;
thereby exhibiting alternately certain signals through a hole cut in the face
of the fixed screen, and to give motion to model semaphores, discs, cross
arms or other form of signal employed on railways, alternate currents being
used, and these may be "persistent" or "temporary," as may be required,
depending upon the number of wires employed.
Another part of my Invention relates to improvements in transmitting
signals on railways from one part of the line to another part, and is specially
applicable to tunnels and heavy. gradients. Hitherto it has been the custom
to transmit currents by hand in order to indicate if the line is "clear" through

page_text: the tunnel or other portion of the railway, and sometimes these currents are
transmitted automatically by the wheels of the train passing over certain
spring treadles or levers fixed near the rails in such manner that as each wheel
passes over, the lever being depressed, actuates the transmitting key or
commutator, and couples up the electric circuit.
Now my improvement consists in a combination of these two arrangements in
such manner that as soon as a train is "clear" of a tunnel or gradient the
signal line clear" shall be transmitted back to the station last passed
automatically, but that in the event of the train breaking down in the tunnel
or gradient the conductor or guard of such train can transmit by hand certain
preconcerted signals to the stations fore and aft which shall serve to indicate
that the train has come to a standstill, and allow time to stop all approaching
trains in both directions. In order to accomplish this, I employ two wires,
the first is connected with a battery and indicator with bell or gong attached,
and is then to be taken along the line to the point where it is desirable to fix
the automatic apparatus; from thence it is joined to the second wire, which is
led back again to the station, where the indicator is fixed, and is then
connected with a second indicator, the difference in these two indicators being
that the coils of the first are wound with moderately thick wire, but the coils
of the second indicator are wound with very fine wire. One end of the
battery is to be put to earth," the other is connected to the indicator with
the thick wire coils, and thence the communication is made along the first
line wire to the automatic connecting apparatus (presently to be described)
from thence through the second line wire to the indicator with the fine wire
coils, and, finally to "earth," thus forming a completely closed circuit without
a break, the battery current passing first through the thick wire coils, and
afterwards through the thin wire coils meets with so much resistance from
these latter that the first indicator does not act but only the second; and this
second indicator being always "on," serves to show that this circuit is complete
throughout its entire length, and that the apparatus is in perfect order. Now
it will be at once evident that if the first wire is put to "earth" at any point
or points along the line without the necessity of breaking the circuit, the
"resistance" of the fine wire coils is removed, and its indicator in turn ceases
to act, but the indicator of the thick wire coils is immediately called into play,
and the required signal transmitted and exhibited at the distant station or
stations. As soon as the first wire is detached from "earth," the resistance
of the fine wire coils is established, and the thick wire coils cease to act;
thus the two indicators work perfectly simultaneously, but only one at a time
electrically. If the thick wire coils are in action electrically, the thin wire

page_text: coils are thrown out, and vice versa, and thus double security is obtained in
the proper action of this instrument. I place on the dial plate the signal
"line clear" on the right-hand side, and "train through," or any other con-
ventional signals, as "train in," "train out," as may be desired, on the left,
and both indicators point to this latter signal whenever the first wire is put to
"earth."
1
Another part of my Invention relates to improvements in apparatus for
making and breaking the connection between the line wire and earth at any
part of the circuit without severing the line wire. For this purpose, when
this apparatus is to be worked by hand, and only momentary contacts are
required, I employ a small iron tube, at one end of which is firmly fixed an
india-rubber bag, the other end of this tube is bent in the form of the letter U,
and by a proper union a further length of tube is screwed on and taken up
the telegraph post or other suitable place so as to be out of the way. An
insulated wire from the first line wire is then passed down this end of the
tube towards the U-bend, the tip of which insulated wire is to be left clear
from the insulating material for about a of an inch. The U-bend is then to
be partially filled with mercury and the iron tube permanently connected with
earth as soon as it is required to transmit a single or any preconcerted code
of signals to a station to announce that a train has broken down or otherwise
become disabled. It is only requisite for the guard or conductor to grasp the
india-rubber bag suddenly, when the air contained therein will force the
mercury in the U-bend up the pipe is which the insulated wire is placed, and
on coming into contact therewith will immediately connect the line wire to
earth and the signal will be received at the station; upon the guard releasing
his grasp the mercury descends and the contact ceases. Thus it will be seen
that no interruption of the line wire circuit takes place, and that no contact
springs are employed, which can never be depended upon when fixed in the
open air on account of damp, corrosion, or dirt getting between the points of
spring contacts. When this arrangement of contact apparatus is acted on
automatically, as, for instance, by the passing of a train, it is very desirable
that the contact with the mercury should be prolonged for a short interval,
and as this would not be the case when the contact apparatus is acted on by
the apparatus shortly to be described I modify the arrangement of the contact
apparatus by placing a valve in one leg of the U-bend near the upper end;
this valve I prefer to construct of a simple ball or sphere, one or more notches
are cut in the edge of the valve socket; this valve only opens upwards. Now
when the mercury is forced along the U-bend a portion passes through the
valve; the pressure being taken off the bag the valve falls, but the mercury

page_text: is retained in contact with the insulated wire until it has gradually passed
back again into the lower portion of the U-bend by means of the notches cut
in the valve socket, a prolonged contact is thus obtained and the signal remains
exhibited at the station for the required interval. The apparatus to be fixed
on the line of railway to work this instrument automatically consists of a
spring lever or treadle placed near the rail in any suitable position, and is
operated upon by a spring trigger or roller fitted to the guard's van; this
trigger can be elevated or depressed as may be required, and in the event of
a train having more than one break van the trigger is to be elevated out of
the way of the spring lever to every such guard's van except the last one, and
this being lowered will come in contact with the spring lever fixed near the
rails; and depressing same will operate upon the mercurial contact piece before
described, the india-rubber bag being placed beneath such spring lever or
otherwise pressed by the same. Sometimes I employ this mercurial contact
apparatus to work telegraphic signals without the battery circuit being always
closed. For this purpose I keep the circuit of the first wire permanently to
"carth" at each end and employ the second wire to convey the battery current,
and upon contact being made, either by hand or automatically, at any portion
of the circuit, the current from the battery divides, and part goes to the
instrument at one side, say, the right, and part goes to the instrument to the
left, working the indicator simultaneously.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Edward Tyer in the Great Scal Patent Office, on the 6th
July 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
TYER, of No. 15, Old Jewry Chambers, in the City of London, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of January, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Edward Tyer, Her special licence that 1. the said Edward Tyer,
my executors, administrators, and assigns, or such others as I, the said
Edward Tyer, my 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,

page_text: exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
APPARATUS USED IN TRAIN SIGNALLING ON RAILWAYS," upon the condition (amongst
others) that I, the said Edward Tyer, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and seals, should
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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Edward Tyer, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say :-
This Invention has for its object improvements in apparatus used in train
signalling on railways. Hitherto in signalling trains by means of the "step by-
step," or dial telegraph very great uncertainty has been found to exist from
what is technically known as "tripping," and this is caused in numerous instances
by the transmitting key used by the signalman being worked at too great
a speed causing the distant instrument to "trip," or lag behind, and thereby
exhibit one particular signal at a station, and quite a different one at another
station. At other times the "tripping" has been caused by bad contact
especially where alternately reversed currents have been employed, the
requisite time for the efficient working of the instrument not having been
allowed for in the construction of the transmitting key, the electric currents
being sent faster than the mechanical arrangements can keep pace with. Now
in order to avoid these irregularities I arrange my instruments in pairs in such
manner that if it is required to transmit two or more currents along the same
wire in the same direction the indication on the dial will only record "one
signal" and this arrangement has the further advantage that after the
signalman has forwarded one signal which appears on the dial of the distant
instrument he can transmit two, threc, or more intimations generally known
as beli or gong call signals in rapid succession without altering in any way
the previous signal exhibited on the dial plate of the distant instrument.
For this purpose I so connect up the instruments that "copper" currents
are sent from one station, causing the dial instrument both at the sending and
receiving stations to move one "step, and "zinc" currents are forwarded from
the distant station, thereby causing the dials of both instruments to move the
second step, and so on, first " copper" current and then "zinc" current in
regular and alternate succession, the currents originating alternately at the

page_text: two stations. By this method very great regularity is obtained, and the
instruments work in perfect unison without tripping. In the Specification of
a Patent granted to me and dated November 29th, 1861 (No. 3015), I have
explained several plans for converting the oscillatory movement of the electro-
magnetic apparatus into a rotary movement of a wheel and axle carrying an
index or hand pointing in succession to the letters of the alphabet or other
signs engraved on a fixed dial plate. Now while either of these arrangements
are applicable for giving the required movement to the index of the dial, yet I
prefer to construct my instruments with a moveable disc revolving behind a
fixed screen, and dividing this disc into six equal paris; I also cut an opening
in the fixed screen equal in extent to one-sixth of the revolving disc, so that
only one portion is visible at a time. On the disc I prefer to engrave the fol-
lowing signals, 1st, "train ready;" 2nd, "train may leave;" 3rd, "train left;"
4th, all right," 5th, "line blocked;" and 6th, "line clear." The first and third
signals are painted or engraved black on a white ground; the 2nd, 4th, and 6th
white letters on a pale green ground; and the 5th, white letters on a red
ground.
This arrangement is shewn in Figure 1, Sheet 1, where A represents the disc
having the several signals engraved thereon in consecutive order; Figure 2
is the front view of the fixed screen having the opening B cut in it, through
which the signals engraved on the disc appear in succession. Figure 3, Sheet 1,
represents the back view of the screen with the electro-magnetic apparatus
attached; and Figure 4 is the side view of the instrument fitted up complete
with the transmitting key or "plunger." As soon as the 5th signal is exhibited
on the dial plate, the revolution of the wheel and axle carrying the revolving
disc, is so constructed as to raise a small semaphore signal on the upper por-
tion of the dial plate, and this small semaphore remains raised until the 6th
signal of "line clear" is received, when it instantly drops to its normal
position. This contrivance is represented in Figures 3 and 4, where a small
pin A fixed to the axle of the wheel B presses against the light lever C, one
end of which passing between two pins fixed near the axle of the semaphore D
causes the same to rise at the 5th signal, and appear at the back of a slot in
the fixed screen, but upon the 6th signal being transmitted, the pin A passes
the end of the lever B, and the semaphore falls by its own
gravity. The exterior appearance of the semaphore is shewn in
Figure 2, and the corresponding signal of "line "blocked" appears
through the screen. The arrangement of the transmitting key is simply a
"plunger," the piston rod of which is tipped with ebonite at one extremity,
and upon being forced down by the hand of the operator the "tip" pushes

page_text: away a spring to which is screwed the line wire, and this spring upon being
further depressed comes into contact with certain connections of the battery
and earth, and allowing the current to flow to the distant station causes the
disc to revolve one step, and after having so caused the disc to revolve one
step, he can send any desired number of bell or gong call signals without
altering the position of the disc. This key or "plunger" is shewn in Figures 4
and 5, attached to the complete instrument; Figure 4 being a side view, and
Figure 5, a front view, the same letters in both Figures refer to the same
parts. E is a piston working by means of a helical spring in the cylinder F,
the end of the piston rod is tipped with ebonite G at one extremity; H is a
spring in connexion by means of the screw I with the line wire and instru-
ment coils; this spring presses against the stud K in connection with "earth;"
two plates L, M, are fixed against the back of the case, one attached
to "earth," the other to one pole of the battery, the remaining pole of the
battery is screwed to the plate N; an insulated spring O is attached to the
line wire spring H, and a further spring P is attached to the
plate N. By this arrangement it is evident that only one series of currents
can be transmitted by the key causing only one signal to appear at the home
and distant stations through the fixed screen, and that any number of "call"
signals" can be sent without altering the position of the disc at either station.
The arrangement of mechanism for causing the disc to revolve is
herein-after described. These keys may be arranged in pairs or
triplets as may be required, and only one battery employed, should more than
one instrument be placed on the same dial. The distant station is fitted up
with a similar instrument, but the battery connections are reversed, so that
whilst the first instrument forwards only "copper" currents, the second instru-
ment sends "zinc" currents, causing the disc of both instruments to revolve
the second step, and thus by the alternate transmission of copper and zinc
currents the disc of each instrument revolves and the signals appear in suc-
cession through the opening in the fixed screen.
I would here remark that step-by-step instruments having other arrange-
ments or codes of signals to those above described may also be worked in pairs
by reversed currents in the manner above described.
The action of these instruments connected up in pairs with alternate currents
will be easily understood from the following description:-Take for example
two stations, A and B, on the "down" line. Each station is to be fitted with
one of these instruments with bells or gongs for calling attention in the usual
manner. A is to have its key connected for "copper" currents, B for "zinc "
currents.
The normal state of both instruments is "line clear" and the

page_text: semaphore down, A requires to start a train; he presses on the plunger, which
transmits a "copper" current to B, causing both discs to move one step and
exhibit through the screens "train ready;" this can be followed by two or
more currents of the same description for the purpose of sounding the bell or
gong, and giving the required call signals thereon without altering the discs.
B, receiving the signal of "train ready," replies by pressing his "plunger,"
and this being fitted with "zine" currents, causes both discs to move another
step, and the permissive signal of "train may leave " appears.
As
soon as the train has started from A the signalman presses his plunger and
gives "train left," a copper current being required to do this and he only
having controul of copper currents; B sends an acknowledgment by a zinc
current "all right;" and thus by one station A transmitting copper currents
and the other station B transmitting only zinc currents, the disc is caused to
revolve, and the signals engraved thereon appear alternately through the hole
in the fixed screen.
Another part of my Invention relates to an improved arrangement of per-
manent magnets in connection with electro-magnets for the purpose of giving
angular motion to the needles, hands, or pointers of telegraph instruments.
and consists of employing two permanently magnetic rings fixed end to end
on the same axle something like the figure 8. These rings have an opening
or notch made in each about half way through and two very fine saw cuts
through the remaining metal, thereby separating the ring, but with
the poles almost in contact. The horns of the electro-magnetic coil or
coils are formed to fit into these openings, allowing just suflicient space
for the amount of oscillation required. By this arrangement the permanent
magnetic force is concentrated at the openings near the fine saw cuts, and
the full effect of the electro-magnetic attractive and repulsive influence is
obtained.
Figure 1, Sheet 2, represents this arrangement. A and B are two magnetic
rings fitted end to end and mounted on an axle C. These rings have an opening
in each, D, D, and two fine saw cuts E, E, through the remaining metal.
The horns" of the electro-magnetic coil are shewn at N¹, S9. As soon as
a current of electricity is transmitted through the coil or coils of the electro-
magnet the "horns" receive polarity n and s, and attract and repel the mag-
netic rings either to the right or left, according to the direction of the current
sent through the coils, as well understood. The horns of the electro-magnet
partially filling up the opening in the rings and the poles of the
permanent magnets being only separated by the two fine saw cuts, the mag-
netism of the latter is not only preserved as if a keeper were attached, but the

page_text: full and combined effect of the electro-magnetic attraction and repulsive
influence is obtained, and the arrangement works with a minimum of battery
power.
Figure 2 represents a side view with one coil attached. The letters refer
to the same parts in each Figure.
Figure 3 represents an end view fitted with a pair of coils, and Figure 4 a
side view of the same. A, A, the rings; B, B, the openings; C, C, the fine
saw cuts; N, S, the horns of the clectro-magnetic coils; D, E, the coils of
the electro-magnet; F, the axle. I employ this arrangement for heavy work
where more power is required than can be obtained with a single coil as in
the former described arrangement.
I apply this arrangement to work the pallets of the step-by-step telegraph
previously described, to give angular motion to the needles or "indices" of
train-signalling telegraphs, to work relays," to move discs behind fixed
Screens, thereby exhibiting alternately certain signals through a hole cut in the
face of the fixed screen, and to give motion to model semaphores, discs, cross
arins, or other form of signal employed on railways, alternate currents being
used, and these may be "persistent" or "temporary," as may be required,
depending upon the number of wires employed.
The application of this arrangement to work the pallets of the step-by-step
instrument previously described is shewn at Figures 3 and 4. Q, Q, are the
magnetic rings; R, R, the horns of the electro-magnetic coil S; T, the pallets
working alternately into the toothed wheels U, U; V, the disc fixed to the
axle W.
currents
By transmitting alternately copper and zinc
previously described through the coils S, the rings Q, Q, oscillate, and the
pallets T propel the wheel, axle, and screen V round step by step, and the
signals engraved thereon appear in succession through the opening B in the
fixed screen A.
as
The application of this arrangement to the giving angular motion to the
needles or indices of train-signalling telegraphs is shewn in Figure 5, Sheet 2,
where A, B, are the rings; N¹, S, the "horns" of the electro-magnet; C, a
light arm attached to the axle D, and giving increased angular motion to the
needle or index E; two stops F, F, are screwed into the front of the dial plate
for limiting the extent of the movement as may be required, and the needle
points alternately to the conventional signals such as "train on line" and
"line clear," as are generally usual on railways. The pivots and supports are
all removed in this and the following 3 Figures for the sake of greater per-
spicuity. This arrangement can be fitted in groups of two or four on the same
dial plate as may be required.
i

page_text: Figure 1, Sheet 3, represents a complete instrument with two sets of this
apparatus mounted on the same dial plate, one set for the UP line and the
lower set for the DOWN line. Two plungers for giving alternate currents as
before described are by preference fitted to the lower portion of the case, and
a third plunger for giving bell or call signals. Transient or persistent currents
are employed according to the requirements of the particular line of railway
and the number of line wires. If persistent currents are employed a small pin
or catch is used to retain either of the plungers "home" when pushed in by
the signalinan.
The application of the improved arrangement of permanent and electro-
magnets to the working "relays " (principally employed by me for sounding
bells and gongs) is shewn in Figure 6, Sheet 2. Here the light arm C is
"tipped" at one end and makes contact with the point D of the screw E.
The terminal F serves to connect up the local circuit. A small recoil spring
is used to sever the contact with the point D after the passage of the current
whenever reversed currents are not employed. If reversed currents are used,
then this recoil spring is dispensed with.
The arrangement of this apparatus for moving discs behind fixed screens is
shewn in Figure 7, Sheet 2. In this case in lieu of the light arm C giving
angular motion to a needle or index as in Figure 5, it is attached to a disc D,
having two sets of conventional signals engraved thereon, and these signals
are caused to appear through an opening cut in a fixed dial plate. A small
counterpoise is represented at P to facilitate the adjustments, and by screwing
this higher or lower the instrument can be made to work with either persistent
currents or transient currents, as may be required; if the former, then the
counterpoise is to be lowered until the thin disc hangs vertical; if the latter,
then by raising the counterpoise, the weight thereof being slightly in excess of
the disc, the same will remain on either side to which it may have been
eflected by the electric current. Figure 2, Sheet 3, represents a com-
plete instrument fitted with two sets of this apparatus mounted on the same
dial with "plungers as before described for alternately transmitting reversed
currents.
"
Figure 8, Sheet 2, represents this arrangement applied for giving motion
to model semaphores, cross arms, or other form of signal employed on rail-
ways. In this case the light arm C gives motion to the model signal D. The
whole of the parts are the same as previously described, and will be readily
understood by inspection of the Figures. Persistent or transient currents may
be employed as required.
Figure 3, Sheet 3, represents a complete instrument fitted with two sets

page_text: of semaphores mounted on the same dial plate, with "plungers," as previously
described.
Another part of my Invention relates to improvements in transmitting signals
on railways from one part of the line to another part, and is specially applicable
to tunnels and heavy gradients. Hitherto it has been the custom to transmit
currents by hand in order to indicate if the line is "clear" through the tunnel
or other portion of the railway, and sometimes these currents are transmitted
automatically by the wheels of the train passing over certain spring treadles
or levers fixed near the rails, in such manner that as each wheel passes over,
the lever being depressed actuates the transmitting key or commutator, and
couples up the electric circuit.
Now my improvement consists in a combination of these two arrangements
in such manner that as soon as a train is "clear" of a tunnel or gradient the
signal "line clear" shall be transmitted back to the station last passed auto-
matically; but that in the event of the train breaking down in the tunnel or
gradient, the conductor or guard of such train can transmit by hand certain
preconcerted signals to the stations fore and aft, which shall serve to indicate
that the train has come to a standstill, and allow time to stop all approaching
trains in both directions. In order to accomplish this employ two wires,
the first is connected with a battery and indicator with bell or gong attached.
and is then to be taken along the line to the point where it is desirable to fix
the automatic apparatus, from thence it is joined to the second wire, which is
led back again to the station, where the indicator is fixed, and is then con-
nected with a second indicator; the difference in these two indicators being
that the coils of the first are wound with moderately thick wire, but the coils
of the second indicator are wound with very fine wire. One end of the battery
is to be put to "earth," the other is connected to the indicator with the thick
wire coils, and thence the communication is made along the first line wire to
the automatic connecting apparatus, (presently to be described,) from thence
through the second line wire to the indicator with the fine wire coils,
and, finally, to "earth," thus forming El completely closed circuit
without a break, the battery current passing first through the thick wire coils.
and afterwards through the thin wire coils meets with so much resistance from
these latter that the first indicator does not act, but only the
second, and this second indicator being always
"on," serves to shew
that this circuit is complete throughout its entire length, and that the apparatus
is in perfect order. Now it will be at once evident that if the first wire is put
to "earth" at any point or points along the line without the necessity of break-
ing the circuit, the "resistance" of the fine wire coils is removed, and its

page_text: indicator in turn ceases to act, but the indicator of the thick wire coils is
immediately called into play, and the required signal transmitted and exhibited
at the distant station or stations. At soon as the first wire is
detached from "earth," the resistance of the fine wire coils is established, and
the thick wire coils cease to act. Thus the two indicators work perfectly
simultaneously, but only one at a time electrically; if the thick wire coils arc
in action electrically the thin wire coils are thrown out, and vice versa, and
thus double security is obtained in the proper action of this instrument. I
place on the dial plate the signal "line clear" on the right-hand side, and
train through," or any other couventional signals as "train in," "train out,"
as may be desired on the left, and both indicators point to this latter signal
whenever the first wire is put to "earth."
<<
Figure 9, Sheet 2, represents this arrangement, where A is the battery;
C, the "copper" end; Z, the zinc end; a wire from the copper end passes
into the instrument, and is connected to the coils B wound with thick wire,
and giving motion to the first indicator L, and also to the hammer that strikes
the bell or gong K. It is then connected to the first line wire, which is taken
along the railway to the point D where the automatic apparatus is fixed; from
thence connected to the second line wire, and led to the second indicator 12,
having thin wire wound on the coils E, and, finally, to "earth;" the zinc end
of the battery is also connected to "carth." The arrows shew the direction
of the current forming a completely closed circuit, without breaks in the normal
state of the instrument; the current, although passing through the thick wire
coils, meet with so much resistance, by afterwards passing through the thin wire
coils, that the indicator of the former does not act electrically, a small spring
is employed to retain this indicator over to the signal "on" the upper indi-
cator 1, on the contrary, being influenced by coils wound with thin wire and
suitably adjusted, acts clectrically and points to the same signal "on." Thus
whilst one indicator is acting mechanically, the other is acting electrically,
although the current is passing through the coils of both at the same time.
Now in order to give the required signal "clear" or "train through," as may
be desired, it is only requisite to connect the line wire to earth at any part of
the circuit, say, at the point F, when immediately the resistance is removed
from the first indicator I, and the electric current is allowed to
act with its full energy upon indicator 12, the upper indicator ceases to act
electrically, and flies over to "clear," either by gravity or a small spring, whilst
the lower indicator comes into play electrically, the gong or bell sounds, and
the indicator points to "clear."
Figure 1, Sheet 4, represents a back view of the instrument employed,

page_text: A, A, the coils of an electro-magnet wound with moderately thick wire; the
armature B is mounted to an axis and held by the cock C; a small spring D
serves to bring back the armature, a light arm E gives motion to the first
indicator I, and a wire F having a hammer bob G at the end strikes the hell
or gong H each time the armature B is attracted by the electro-magnet A, A.
The upper coils K, K, are wound with fine wire, and give motion to the indicator
1; the coils represented in the Figure are ordinary galvanometer coils, but the
arrangement of magnetic rings and electro-magnets previously described will
answer equally well; a light coiled hair spring or small weight is attached to
the axle L near the dial plate, which serves to bring the indicator to "clear"
when the current ceases to flow through the coils K, K.
Another part of my Invention relates to improvements in apparatus for
making and breaking the connection between the line wire and earth at any
part of the circuit without severing the line wire; for this purpose when this
apparatus is to be worked by hand and only momentary contacts are required,
I employ a small iron.tube, at one end of which is firmly fixed an india-rubber
bag, the other end of this tube is bent in the form of the letter U, and by a
proper union a further length of tube is screwed on and taken up the telegraph
post or other suitable place, so as to be out of the way; an insulated wire from
the first line wire is then passed down this end of the tube towards the U-bend,
the tip of which insulated wire is to be left clear from the insulated material
for about a quarter of an inch. The U-bend is then to be partially filled with
mercury, and the iron tube permanently connected with earth. As
soon as it is required to transmit a single or any preconcerted code
of signals to a station to announce that a train has broken down or otherwise
become disabled, it is only requisite for the guard or conductor to grasp the
india-rubber. bag suddenly, when the air contained therein will force the mer-
cury in the U-bend up the pipe in which the insulated wire is placed, and on
coming into contact therewith will immediately connect the line wire to earth,
and the signal will be received at the station; upon the guard releasing his
grasp the mercury descends and the contact censes. Thus it will be seen
that no interruption of the line wire circuit takes place, and that no contact
springs are employed which can never be depended upon when fixed in the
open air, on account of damp, corrosion, or dirt getting between the points of
spring contacts.
This apparatus is shewn in Figure 2, Sheet 4, where A, A, is the iron tube;
B, the india-rubber bag; C, the U-bend partially filled with mercury; D. the
insulated wire connected with the line wire. This apparatus is used in con-
nexion with that previously described, one of these contact pieces is repre-

page_text: sented at G, Figure 9, Sheet 2.
When this arrangement of contact apparatus
is acted on automatically, as for instance, by the passing of a train, it is very
desirable that the contact with the mercury should be prolonged for a short
interval, and as this would not be the case when the contact apparatus is acted
on by the apparatus shortly to be described, I modify the arrangement of the
contact apparatus by placing a valve in one leg of the U-bend near the upper
end; this valve I prefer to construct of a simple ball or sphere, one or more
notches are cut in the edge of the valve; this valve socket only opens inwards;
now when the mercury is forced along the U-bend a portion passes through
the valve, the pressure being taken off the bag the valve falls, but the mercury
is retained in contact with the insulated wire until it has gradually passed back
again into the lower portion of the U-bend by means of the notches cut in the
valve socket; a prolonged contact is thus obtained, and the signal remains
exhibited at the station for the required interval.
Figure 3 is a modified arrangement of the former apparatus, and is used
whenever it is required that the contact should be prolonged. for a short
interval. A, A, the tube; B, the bag; C, the U-bend partially filled with
mercury; D, the insulated wire passing into a chamber E; F is a valve; G, a
notch cut in the edge of the valve socket to allow the mercury to return
gradually into the U-bend; a small spring H is employed to retain the ball
valve in position. The apparatus to be fixed on the line of railway to work
this instrument automatically consists of a spring lever or treadle placed uear
the rail in any suitable position, and is operated upon by a spring trigger or
roller fitted to the guard's van; this trigger can be elevated or depressed as
may be required; and in the event of a train having more than one break van
the trigger is to be elevated out of the way of the spring lever to every such
guard's van except the last one, and this being lowered will come in contact
with the spring lever fixed near the rails, and depressing same will operate
upon the mercurial contact piece before described, the india-rubber bag being
placed beneath such spring lever or otherwise pressed by the same.
Figures 4 and 5, Sheet 5, represents a front and side view of a trigger to
be fixed to the last guard's van of a train, and consists of a bar A sliding in
suitable frames B, having a helical spring C attached; at the lower end a roller
is fixed D, and at the upper end of the bar a ring E is attached, to this is fas-
tened a cord or chain in order that the guard can clevate the roller out of the
way when requisite; a hook F is to be permanently fixed to the guard's van,
and when the train is "made up" the last van is to have one of these
triggers" hooked on. Whenever during the passage of a train over the point
or place along the line, where it is desired to transmit signals automatically
"

page_text: the "trigger" passes over an ordinary spring lever. and depressing same causes
the mercurial contact to come into play, and the requisite signals are trans-
mitted, serving to indicate the passage of that particular train in its entirety,
either through a tunnel or up a heavy gradient: on the other hand should the
train break away and a portion be left in a tunnel, the signal "line clear"
would not be given to the signal man in the rear. because the guard's van
being the last carriage having this spring trigger attached would not have
passed over the trendle or lever, and thus safety is secured to the disabled
train; and by means of the mercurial contact piece previously described, which
I propose to place along a tunnel at about every one hundred yards, it would
only be requisite for the guard to go back a maximum distance of fifty yards.
where by grasping one of these bags he could transmit signals of distress to
the stations in the rear, and that without carrying any batteries. wires, or any
apparatus whatever.
Figure 6. Sheet 5, shows this arrangement. A and B are two instruments
one at each signal box, fitted with indicator and bells, and in connexion with
the first line wire and earth; the second line wire is in connection with the
battery C; in the event of a break down on any portion of the line between
the two signal boxes, the guard goes back to the first mercurial contact piece
M, previously described, and can there transmit signals of danger to the signal-
man in advance and in the rear, and stop any approaching train on either or
both lines as may be requisite.
Sometimes I employ this mercurial contact apparatus to work telegraphic
signals without the battery circuit being alway closed. For this purpose I
keep the circuit of the first wire permanently to "earth" at each end, and
employ the second wire to convey the battery current. and upon contact being
made either by hands or automatically at any portion of the circuit the current
from the battery divides, and part goes to the instrument at one side, say the
right. and part goes to the instrument to the left, working the indicators
simultaneously.
In witness whereof, I, the said Edward Tyer, have hereunto set my hand
and seal, this Fifth day of July, in the year of our Lord One thousand
eight hundred and sixty-five

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