Iм- PROVEMENTS IN PNEUMATIC APPARATUS FOR THE TRANSMISSION AND INDICATION OF SIGNALS
Year: 1872

page_text: LETTERS PATENT to Marshall Arthur Wier, of No. 9, Great Win-
chester Street, in the City of London, for the Invention of "Iм-
PROVEMENTS IN PNEUMATIC APPARATUS FOR THE TRANSMISSION AND INDICATION
OF SIGNALS."
Sealed the 6th September 1872, and dated the 8th March 1872.
PROVISIONAL SPECIFICATION left by the said Marshall Arthur Wier
at the Office of the Commissioners of Patents, with his Petition,
on the 8th March 1872.
I, MARSHALL ARTHUR WIER, of No. 9, Great Winchester Street, in
5 the City of London, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN PNEUMATIC APPARATUS FOR THE TRANSMISSION AND
INDICATION OF SIGNALS," to be as follows:-
My Invention relates to a novel construction, arrangement, and
adaptation of apparatus for sending and receiving visible or audible
signals by pneumatic means.

page_text: The principal apparatus consists of a sending instrument or com-
municator connected by tubes with a receiving instrument or indicator,
and of a repeating apparatus or tell-tale to indicate at the sending end
that a signal has been duly received at the receiving end, and in some
cases that it has been acted upon. The communicator is fitted with a
cylinder and piston for compressing the air, so arranged that on the
piston being forced into the cylinder to the desired extent the commu-
nication between the said cylinder and the tube or tubes leading to the
indicator shall be closed by self-acting means, so that the air forced into.
the tube or tubes is retained therein whether the piston be fitted to the
cylinder perfectly air-tight or not..
In some cases I arrange the air compressing & self-acting closing
apparatus in such manner as to avoid the employment of distributing
and equalising valves between the said air compressing instrument and
the tubes; but in other cases in which an appliance of that kind is
necessary, instead of using a separate valve to govern the inlet and
outlet of air to and from each tube, as set forth in the Specification of a
Patent granted to A. McN. Weir and myself, dated September 24th,
A.D. 1868, and bearing Number 2929, I employ a single rotating
conical or cylindrical plug, flat disc, or slide valve provided with an
aperture by which any one of the several tubes leading to the indicator
(which all open in the face against which the said plug or other, valve
works) may be placed in communication with the air compressing
apparatus, the other tubes remaining shut off therefrom, but opened
to the atmosphere by means of suitably disposed grooves or slots formed
in the said plug or other valve, which may be moved by the said lever
handle as operates the compressing apparatus.
When it is required to adapt this apparatus to the purpose of sending
signals indicative of numbers, as, for example, in the case of directing
the fire of ships' guns, in which it may be necessary to indicate the
degrees to which the guns are to be trained. by two or three figures at
once, I avoid the necessity for employing a separate set of air com-
pressing apparatus for each denomination of figure by combining
together two or more of the above-mentioned plugs or valves so as to
act in unison with each other, one plug or valve governing the tubes
leading to the "units" figures in the indicator, another, those. leading
to the "tens" figures, a third those leading to "hundreds" figures, and
so on. The apertures and grooves or slots in the plugs or valves for

page_text: admitting and letting out the air are so arranged in relation to the
tubes, and the motion of the plugs or valves in relation to each other so
regulated by wheelwork or otherwise, that each complete revolution of
the "units" plug or valve brings the outlet aperture of the
"tens"
plug or valve opposite a fresh "tens" tube, and so on to any required
extent. The plugs or valves are adjusted to their required position by
the aid of a pointer working over a dial face, and connected with the
handle operating them.
The indicator when arranged to show visible signals may consist of a
dial face with the various signals marked thereon, and having a pointer
working over it; or of a dial face having openings cut therein, behind
which shutters or flaps or a revolving drum with signals marked thereon
are made to rise and fall or to revolve. When the signals are made
apparent by means of shutters or flaps, I prefer to use for each signal
to be indicated a separate transmittor, which may consist of an expanding
air chamber, made by preference of mineralised india-rubber, a small
cylinder with piston or plunger, a cup floating in mercury, or other
convenient transmitting medium.
When indicating by means of a pointer I employ the following
apparatus in order to impart the proper amount of motion thereto :-
When the arc of action is large an intermediate axis carries a
number of tail pieces corresponding to and acted upon by the trans-
mittors. The tail pieces are so arranged in relation to the axis and to
certain fixed stops, that each one on being acted upon by its corre-
sponding transmittor is capable of imparting a certain amount of angular
motion to the said axis, but no more, each transmittor and tail piece
acting upon the axis independently of the others. The axis carrying
the tail pieces is connected to that of the pointer in such manner
that the motion communicated to it by the tail pieces is conveyed
in any desired proportion to the axis of the pointer. When the arc
over which the pointer is to be moved is small the tail pieces may
be placed direct on the axis of the pointer and made to move it to
definite positions without employing the intermediate axis.
When indicating by means of shutters or flaps I employ a shaft or
axis on which is centred loosely a series of tail pieces corresponding
to the number of the transmittors, and so arranged that each is capable
of acting upon a shutter when moved by its corresponding transmittor.
In order to ring a call bell there is fixed on the above-mentioned axis

page_text: close to each tail piece a ratchet wheel, into which ratchet clicks on the
said tail pieces take, so that whenever one of the latter is moved by a
transmittor the click causes the axis to make a partial revolution and
to act by suitable wheelwork or otherwise upon the hammer of a bell.
The indicator when arranged to give audible signals, as by the strokes
of a bell, may be fitted with one of the transmittors before mentioned,
which is made to raise a rack gearing into a pinion in connection with
a wheel having projecting spokes, which as they revolve cause a hammer
-to strike a bell as may be required. A valve connected with the trans-
mittor is opened by the bell mechanism in order to liberate the air after
the bell has been rung.
The repeating apparatus or tell-tale when arranged to indicate that
a signal has been received, may consist of a tap or valve placed at
the receiving end of the attention bell tube; this tap or valve being
opened by the attendant at the receiving end when the attention bell
rings allows a portion of the air that has rung that bell to return to
the operator at the communicator by a second tube and ring the reply
bell or move an index or shutter. Or if desired a repeating signal may
be indicated at the communicator for each signal sent, by arranging a
series of small shutters or other indicating media corresponding to the
signals employed, so placed and acted upon that the opening of the
tube to the atmosphere at the receiving end either by the hand of
the receiver or by mechanism set in motion automatically in the act
of obeying the signal shall liberate the pressure of air in the tube and
allow the said indicating media to operate.
A modification of this apparatus is specially applicable to signalling
on railways, as in the "block" system now worked by electricity.
In some cases when employing great lengths of tube between the
communicator and indicator, I place a valve at or near the middle of
the length of such tube so arranged as to open and allow the air to pass
towards the indicator, but to close and prevent the most distant portion
from returning towards the communicator; by this means when a self-
acting relief valve or apparatus exists in both the communicator and
indicator the air escapes at both ends of the tubes instead of at one end
only, whereby time is saved.
In some cases it is necessary or convenient in signalling apparatus of
this descrintion to join together lengths of tube in such manner that

page_text: they may be easily separated, as, for example, when the apparatus is
applied to railway trains to signal from "guard" to "driver." To effect
this I fit to the ends of the tube to be joined together a piece of brass
tubing having one side cut away, so that when the two parts are put
together they form a kind of half lap, which is locked together by means
of a bayonet joint. A valve may be fitted into the end of each tube
in such manner that when the joint is put together the valve is opened
and air can flow through, but when the joint is separated the valves
close and air can no longer pass.
filed by the said Marshall Arthur Wier in the Great Seal Patent
Office on the 7th September 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MARSHALL
ARTHUR WIER, of No. 9, Great Winchester Street, in the City of
London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of March, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Marshall Arthur Wier, Her special
licence that I, the said Marshall Arthur Wier, my executors, dminis-
trators, and assigns, or such others as I, the said Marshall Arthur Wier,
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, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN PNEUMATIC APPARATUS FOR THE TRANSMISSION AND INDICATION
OF SIGNALS," upon the condition (amongst others) that I, the said
Marshall Arthur Wier, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Inven-
tion, 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

page_text: declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, and accompanying Drawings, that is
to say:
1
My Invention relates to a novel construction, arrangement, and
adaptation of apparatus for sending and receiving visible or audible
signals by pneumatic means.
The principal apparatus consists of a sending instrument or com-
municator connected by tubes with a receiving instrument or indicator
and of a repeating apparatus or tell-tale to indicate at the sending end
that a signal has been duly received at the receiving end and in some
cases that it has been acted upon. The communicator is fitted with a
cylinder and piston for compressing the air, so arranged that on the
piston being forced into the cylinder to the desired extent the com-
munication between the said cylinder and the tube or tubes leading to
the indicator shall be closed by self-acting means, so that the air forced
into the tube or tubes is retained therein whether the piston be fitted
to the cylinder perfectly air-tight or not.
In Sheet 1 of the Drawings Figure 1 represents a sectional clevation
of a communicator; Figure 2, part plan and part horizontal section of
same.
A is the cylinder; B, the piston for compressing the air operated as
required by the handle K.; C is a pad of india-rubber or other elastic
substance forming a seat against which the face D of the piston is
pressed on its descent in the cylinder so as to close communication
between the order tube E and the cylinder to retain the air in the tube
E, as above described. Figure 3 shows another method of effecting the
same object, F is a tap fitted in the order tube E, having a slotted lever
G fixed to the plug thereof; a projecting pin H on the piston B takes
into the slot of the lever G as the piston is depressed, closing the tap F,
and on raising the piston B the pin H opens the said tap.
In some cases I arrange the air compressing and self-acting closing
apparatus in such manner as to avoid the employment of distributing

page_text: and equalizing valves between the said air compressing instrument and
the tubes. One means of effecting this is shown in Figures 1 and 2,
wherein I represents a conical piece or nozzle forming a prolongation
of the order tube E issuing from the cylinder A; the latter is capable
of being swivelled round on the centre J by means of the handle K, so
that the conical nozzle I may be brought over any one of the indicating
tubes L, L, leading to the indicator. The communicator end of each of
these tubes is furnished with an elastic or other suitable seating M, then
on depressing the handle K the first effect is to force the cylinder down,
compressing the spring N, and the nozzle I enters that one of the
seatings M over which it may have been brought, making an air-tight
joint between the desired indicating tube and the air compressing
instrument. The next effect of depressing the handle is to compress the
air in the cylinder forcing it into the tube E, and then to close the
communication between the tubes E and L and the cylinder as before
explained; on releasing the handle the cylinder is raised by the spring N,
and the piece I disengaged from the tube L opening the latter to the
atmosphere.
In other cases in which an appliance of that kind is necessary instead
of using a separate valve to govern the inlet and outlet of air to and
from each tube, as set forth in the Specification of a Patent granted to
Arthur McN. Wier and myself, dated September 24th, A.D. 1868,
No. 2929, I employ a single rotating conical or cylindrical plug, flat
disc, or slide valve provided with an aperture by which any one of the
several tubes leading to the indicator (which all open in the face against
which the said plug or other valve works) may be placed in communica-
tion with the air compressing apparatus, the other tubes remaining shut
off therefrom but opened to the atmosphere by means of suitably disposed
grooves or slots formed in the said plug or other valve, which may be
moved by the same lever handle as operates the compressing apparatus.
Figure 4 shows the conical plug in connection with a compressing
instrument; Figure 5, elevation of a plug showing the air grooves;
Figure 6, elevation of shell of plug showing order tubes; Figure 7,
horizontal section at line a, b, Figure 6, through plug and shell at order
tubes; Figure 8, horizontal section of same through attention bell tube
at c, d, Figure 6. In these Figures the conical plug O is shown as
being rotated by means of a square stem P extending from the piston
which takes into and slides in a corresponding hole in the plug; the

page_text: stem P has a passage Q, by which air is admitted from the cylinder into
the interior of the plug O; R is the aperture in the plug, which being
brought opposite to any one of the order tubes E, as for example E¹
leading to the indicator, places it in communication with the air com-
pressing cylinder, the other tubes remaining open to the atmosphere by
the grooves S in the plug coming opposite to their ends. The grooves S
all lead into the groove S¹ surrounding the plug, which is always in
communication with the atmosphere by the opening T in the shell.
The attention bell tube U is always in communication with the interior
of the plug by means of the groove U¹ and hole R', so that into what-
ever position the plug is turned for sending a signal the attention bell
in the indicator will receive an impulse from the air compressing in-
strument. I prefer to employ a conical plug, but it will be evident
that a flat disc or slide valve with an appropriate seat may be arranged
with the openings and grooves to act in a similar manner.
وو
When it is required to adapt this apparatus to the purpose of sending
signals indicative of numbers, as, for example, in the case of directing
the fire of ships' guns in which it may be necessary to indicate the
degrees to which the guns are to be trained by two or three figures at
once, I avoid the necessity for employing a separate set of air compressing
apparatus for each denomination of figure by combining together two or
more of the above-mentioned plugs or valves so as to act in unison with
each other, one plug or valve governing the tubes leading to "units
figures in the indicator, another those leading to "tens" figures, a
third those leading to "hundreds" figures, and so on. The apertures
and grooves or slots in the plugs or valves for admitting and letting out
the air are so arranged in relation to the tubes, and the motion of the
plugs or valves in relation to each other so regulated by wheelwork or
otherwise, that each complete revolution of the "units" plug or valve
brings the outlet aperture of the "tens" plug or valve opposite a fresh
"tens" tube, and so on to any required extent. The plugs or valves
are adjusted to their required position by the aid of a pointer working
over a dial face and connected with the handle operating them.
"
This arrangement of apparatus is illustrated on Sheet 2, wherein
Figure 16 represents a plan of the dial face of a "communicator
adapted for sending signals for training guns; Figure 18, plan of same
part in section and with part of dial removed; Figure 17, sectional

page_text: elevation through the distributing plugs; Figure 19, elevation of same.
with part of case removed.
A' is the air compressing instrument connected to the shells of the
plugs by the tubes B¹ and Bu C¹ is the units plug, D¹ the tens plug,
both of which are constructed similarly to that last described, except
that instead of the air from the air compressing instrument being
received in the interior of the plugs it is by preference passed from the
tubes through the shells into the grooves E', E¹, in the plugs forming
the outlet apertures, whence it passes into the desired indicator tubes,
when the grooves F¹, F", are brought opposite to them. The plugs are
so geared together (preferably by wheelwork G¹ and G") that for each
revolution of the "units" plug the "tens," plug shall make a tenth of a
revolution so as to bring its outlet aperture F" in communication with
a fresh "tens" indicator tube H¹, each tenth part of a revolution of the
"units" plug bringing its outlet aperture to coincide with the next
successive "units" indicator tube I¹.
plug is turned
"tens" in the
A convenient method of adjusting the plugs to their required positions
consists in arranging a pointer J¹ over a dial face on which the degrees
or numbers to be indicated are marked, the axis K¹ carrying this pointer
carries also a sectoral rack L' gearing into the long pinion G¹ fixed on
the units plug; this pinion G¹ on the units plug gears also with a wheel
of ten times its own diameter fixed on the tens plug. On moving the
pointer J¹ to any given number on the dial face the units
by the gearing described as many times as there are
number to be indicated, and such a further fraction of a turn as will
bring the outlet aperture F¹ in the plug opposite the tube leading to
the mechanism in the indicator for exhibiting the particular unit figure.
required, the "tens" plug being also turned by its connection with the
units plug so as to bring its outlet opening opposite to the tube leading
to the mechanism of the indicator for exhibiting the particular "tens
figure required.
"
In regulating the training of guns where it is necessary to indicate at
one time a direction before the beam, and at another abaft the beam, I
prefer to arrange the pointer with sights M', M", so that the bearing of
the object may be taken thereby, and in order that the movement of
the pointer shall cause the plugs to revolve in the same direction,
whether the direction to be indicated be before or abaft the beam, I
employ a second sectoral rack L", also fixed on the pointer axis, and

page_text: gearing with an intermediate wheel G™ working into the pinion on the
"units plug. When the pointer stands at zero in the position shown
both the racks are to be just out of gear with their respective pinions in
that position movement of the pointer "before the beam," or in the
direction of the plain arrow will bring rack L' into gear with the
pinion G¹ on the "units" plug, the intermediate wheel being disengaged
from the rack L"; movement of the pointer "abaft the beam or in the
direction of the feathered arrow will bring rack L" into gear with the
intermediate wheel G, while the rack L' disengages from the pinion G¹,
thus whichever way the pointer is moved the regulating plugs move
in the same direction, and govern the signals shown in the indicator in
the proper order. To distinguish in the indicator whether the signals
given refer to "before" or "abaft" the beam," a separate plug or valve
may be adapted to the communicator, and may be operated by hand or
automatically from the pointer to open communication between the air
compression instrument to operate appropriate indicating mechanism in
the indicator, to be hereafter described. Other plugs may be employed
if required to give the order to "fire" or "cease firing," or to show the
range of the object fired at, as shown.
The indicator when arranged to show visible signals may consist of a
dial face with the various signals marked thereon, and having a pointer
working over it, or of a dial plate having openings cut therein, behind
which shutters or flaps or a revolving arm with signals marked thereon
are made to rise and fall or to revolve, but by whatever means the
signal is made apparent I prefer to use for each signal to be indicated a
separate transmission, which may consist of an expanding air chamber,
made by preference of mineralized india-rubber, a small cylinder with
piston or plunger, or cup floating in mercury, or other convenient trans-
mitting medium.
When indicating by means of a pointer or drum I employ the
following apparatus in order to impart the proper amount of motion
thereto :-
-
Referring to Sheets 1 and 2 of the Drawings, Figure 9 is a plan of
indicator dial plate and index with part of dial removed to show the
mechanism beneath; Figure 10, elevation of said mechanism; Figure 20,
sectional plan of indicator with revolving drums specially applicable for
indicating combination signals, such as numbers, as described for train-
ing guns and such like purposes; Figure 21, side view of same with part

page_text: of case removed.
In each of these Figures 9, 10, 20, and 21 like
letters refer as nearly as possible to like parts.
An intermediate axis N¹ carries a number of tail pieces O¹ corre-
sponding to and acted upon by the transmittors P¹. The tail pieces 0¹
are so arranged in relation to the axis N¹ and to certain fixed stops Q!
that each one on being acted upon by its corresponding transmittor is
capable of imparting a certain amount of angular motion to the said
axis but no more by means of pins R¹ fixed in the said axis and taking
into slots R" in the bosses of the tail pieces. Each transmittor and tail
piece thus acts upon the axis independently of the others, the pins in the
axis not acted upon by these tail pieces being free and move backwards
in the slots of the bosses of the said tail pieces when the axis is moved
round without moving the tail pieces themselves.
The axis carrying
the tail pieces is connected to that of the pointer or drum by means of
a lever S₁ and slotted plate Sui, as shown in Figures 9 and 10, or by a
sectoral rack and pinion T, T", as seen in Figures 20 & 21, or in any
convenient manner such that the motion communicated to the axis by
the tail pieces may be conveyed in any desired proportion to the axis of
the pointer or drum Z. When the one over which the pointer or drum
is to be moved is small the tail pieces may be placed direct on the axis
of the pointer or drum, and made to move it to definite positions without
employing the intermediate axis.
When indicating by means of shutters or flaps I employ the following
mechanism, see Sheet 1, Figures 11 and 12:-
N¹ is a shaft or axis on which are centered loosely a series of tail
pieces O¹ corresponding to the number of the transmittors P¹, and SO
arranged that each is capable of acting upon a shutter Y, on which a
signal is marked, elevating it behind the opening U' when moved by
its corresponding transmittor. In order to ring a call bell in connection
with this apparatus there are fixed on the axis close to each tail piece a
ratchet wheel V, see Figures 11 and 12, into which ratchet clicks V¹ on
the said tail pieces take, so that whenever one of the latter is moved by
a transmittor the click causes the axis to make a partial revolution, and
to act by a train of wheels W, W, or by other well-known means upon
the hammer of a bell.
Figure 12ª represents a simple form of transmitter annlicable in

page_text: upper end a disc or plate with a signal marked on it Y¹, the plunger
pressed up by the air entering the cylinder below it, and the signal is
rendered visible through the opening U¹ in the case.
The repeating apparatus or tell-tale, when arranged to indicate that
a signal has been received, may cosist of a tap or valve a, see Figure 13,
Sheet 1, placed at the receiving end 6 of the attention bell tube c. This
tap or valve being opened by the attendant or by automatic means at
the receiving end when the attention bell in the indicator rings allows
a portion of the air that has rang that bell to return to the operator at
the communication by a second tube d and to ring the reply bell, or move
an index or shutter in the communicator. Or, if desired, a repeating
signal may be indicated at the communicator for each signal sent by
arranging, see Figure 1, Sheet 1, a series of small shutters, such as e or
other indicating media corresponding to the signals employed, and by
preference having them marked thereon, so placed and acted upon by a
plunger for other similar means in connection with the air compressing
instrument, that on a signal being sent the said shutter e shall either
appear at or disappear from the opening 7 in the communicator, thus
indicating to the operator that he has sent the proper signal, while the
opening of the tube to the atmosphere at the receiving end either by the
hand of the receiver or by mechanism set in motion automatically in the
act of obeying the signal shall liberate the pressure of air in the tube
or plunger and allow the said shutter or other indicating media to
disappear from or appear at the opening, thus indicating to the operator
that his signal has been received and in some cases acted on.
may also be operated in a
The air from the cylinder
the trigger h behind the
The bell mechanism shown in Figure 1
similar manner and for a similar purpose.
acting upon any suitable transmittor P" sets
click of the hammer, and on the liberation of the arm at the receiving
end the spring i discharges the trigger and causes the hammer to strike
the bell. A modification of this apparatus is specially applicable to
signalling on railways as in the "block"
system now worked by
electricity.
"
In Figure 14, Sheet 1, j represents the small semaphore signals used
in the signal box from which a signal is to be sent; k, that in the box
to which the signal is to be sent; 1, the tube leading from an air com-
pressing instrument, the semaphore arms in both boxes being thereby
elevated on receiving the signal, or after the passage of a train the

page_text: signalman in the receiving box depresses a key m in connection with a
tap n by which the tube o is opened to the atmosphere, and the
semaphore arms at both boxes drop to indicate that the line is clear on
releasing the key in the spring p raises it, closing the tap n ready for
another signal.
In some cases it is necessary or convenient in signalling apparatus of
this description to join together lengths of tube in such manner that
they may be easily separated, as, for example, when the apparatus is
applied to railway trains to signal from guard to driver. To effect this;
see Figure 15, Sheet 1, I fit to the ends of the tubes to be joined
together a piece of brass tubing, the projection 9 on one taking into the
recess in the other, a part of a turn then locking the two ends together
in the manner of a bayonet joint, india-rubber or other elastic washers 8
making an air-tight junction. A valve t is fitted into the end of each
tube in such manner that when the joint is put together the valve is
pressed open and air can flow through the passage u formed therein or
around it, but when the joint is separated the valves are closed by means
of the spring o and air can no longer pass.
Having now described the nature of my said Invention, and the
manner in which the same is. performed, I would have it understood
that what I claim as my Invention is,―
Firstly. The application and use of taps or valves or surfaces acting
as such operated by the movement of the piston for closing com-
munication between the air compressing instrument and the order tube
or tubes, substantially as and for the purpose described and shewn.
Secondly. The use in connection with the air compressing instrument
of a nozzle adapted to fit into or against elastic or other suitable seating
for the purpose of making an air-tight joint between any of the
indicator tubes and the air compressing instrument, substantially as
shewn and described.
Thirdly. The air compressing instrument arranged and adapted to
slide or revolve for the purpose of placing it in connection with the
desired indicating tube, substantially as shown and described.
Fourthly. The use of conical plugs or other valves with air grooves
and holes formed therein for regulating and distributing the air to and
from the indicating tubes, constructed, and arranged, and applied substan-
tially as described and shown.
•

page_text: Fifthly. The combination of two or more of the said plugs or valves
for the indication of numbers or other similar compound signals.
Sixthly. The application and use in indicator instruments of loose
tail picces operated by the transmittors and acting upon an axis for
giving motion to an index, drum, or shutter or to sound a bell, sub- t
stantially as described and shown.
Seventhly. The apparatus shown and described whereby the reception
of a signal at the indicator is notified at the communicator by the return
of a portion of the air which gave the signal or by the liberation of the
compressed air from the signalling tube.
Eighthly. The joint or coupling for lengths of tube constructed and
applied substantially as described and shown.
L
In witness whereof, I, the said Marshall Arthur Wier, have here-
unto set my hand and seal, this Seventh day of September, in the
year of our Lord One thousand eight hundred and seventy-two.
MARSHALL A. WIER. (L.S.)
]
1