Improvements in Prepayment Gas Meters, applicable, in part, also to Non-prepayment Meters.
Year: 1891

page_text: Date of Application, 27th Feb., 1891
Complete Specification Left, 27th Nov., 1891-Accepted, 13th Feb., 1892
PROVISIONAL SPECIFICATION.
Improvements in Prepayment Gas Meters, applicable, in part, also
to Non-prepayment Meters.
WILLIAM COWAN, Buccleuch Street Works Edinburgh, Gas Meter Manu-
facturer, &c. do hereby declare the nature of this invention to be as follows:
:-
This invention consists of improvements in, and modifications of, as well as
of additions to, my previous invention for which, under the same title, Letters
Patent have been applied for, the number of the application being 11537, and
the date July 23rd 1890. One part of the present invention is, an improved
method of keeping the lever opening in the side of the valve box gas tight,
and this applies to all the forms of prepayment meters mentioned in my former
application, and is also applicable to non-prepayment meters. Another part of
the invention has reference only, or chiefly, to the coin form of prepayment
meters described in the Provisional Specification of the above date and number.
The present improvements, like those of the previous invention, apply both to
wet & dry gas meters. Instead of using a ground plug, an indiarubber, or
other flexible, sleeve on the axle of the valve lever, I propose, in this inven-
tion, to employ two stuffing boxes; with an air tight chamber between them
which, in some cases, may be filled with fatty, or waxy, material, not liable to
liquify at moderate temperatures. One of these stuffing boxes 1 fix in the wall
of the valve box, and surround, or enclose, it (outside the valve box) by a
chamber, or tube, which is closed at its other extremity & made gas tight, by
means of the other stuffing box, through which, as well as through the one on
the valve box wall, the axle of the lever passes. The valve box is thus
protected from any escape of gas through the lever opening by the intervention,
between it and the atmosphere, of two stuffing boxes with an air tight chamber
between them. In order, however, to increase the security thus afforded, this
chamber, or tube, may be filled with some fatty, or waxy, material, as above
described.
to
I shall now refer to those improvements which are applicable only, or chiefly,
to the coin form of my prepayment meters. In this invention, propose
dispense with most of the mechanism, for discharging the coin into the money
box and for driving the pawl of the prepayment wheel, which was described in
my previous application of the above date and number, and to substitute therefor
more simple means for effecting these purposes. The arrangement of the index
and the prepayment wheel, together with the means employed for opening,
keeping open, and closing, the valve, and also the price changing platforin and
its appendages, will all be, practically, the same as described in my former
application. But in this invention the slot, into which the coin is dropped, will
be joined, or linked, on to the pawl of the prepayment wheel, either on one of
its sides or ends. And it, (the slot) will be similarly joined at its other side,
or end, to the extremity of the pusher, so that all the three, pusher, slot, &
pawl, will move forward and return backward together. But, in order to make
this united action entirely dependent on the presence of the coin in the slot, an
opening is made through the slot, and through this opening the pusher will
pass, unimpeded, and without result, if no coin be present. But, in the event
of a coin being in the slot the opening referred to is closed, or obstructed, with
the result that, the pusher, in moving, carries with it the slot, the coin, and
the pawl, and drives forward the prepayment wheel. In some instances the slot
may be placed at right angles to the pusher and the pawl, and in this case the
opening in the slot will be right through its two sides and in such a position

page_text: that when a coin is present the pusher will act upon the centre, or nearly the
centre, of the coin. But when placed at right angles to the pawl, & pusher,
the slot requires to be kept sufficiently far away from the pawl to allow the
pusher the full length of its travel before it would reach the pawl supposing
no coin to be present. The opening in the slot, on the side nearest the pawl,
is therefore provided with a tube, or else two or more rods, extending out to
the pawl, and to these the pawl is jointed, or pivoted, in such a manner that it
is, practically, one with the slot. The side of the slot which is next the pusher
is also furnished with a short tube, or two or more rods, & through these the
end of the pusher passes into the slot hole. But an annular flange, at the
extremity of this tube, or the rods, combined with a smaller annular flange, or
clse pins, on the pusher, prevents the backward action of the pusher without a
corresponding action of the slot & pawl. Hence, the pusher not only moves the
slot and pawl inwards, but, when withdrawn, brings them back to the normal
position without the necessity for employing springs for either action. In certain
cases springs may be employed, but in the above arrangement they may be
dispensed with.
In some instances, the slot is placed end ways, that is, in the line of the
pusher & the pawl. In this case, the opening is through the end of the slot
next the pusher, and the centre of the edge of the coin is pressed upon when
the pusher advances. In this latter arrangement no tube, or rods, between the
slot and the pawl, are usually necessary, because the diameter of the coin from
edge to edge is generally sufficient to allow the necessary, ineffective, travel of
the pusher within the slot itself, & without requiring any tubular or other
projection.
The travelling slot, suitably guided, is so placed that in the normal position
its upper, or inlet, end, is immediately under a corresponding slot opening in
the roof of the index box so that a coin dropped through the outside opening falls
at once into the travelling slot below. But in order to prevent the escape of
the coin when the slot is in this position and before the pusher has, by pressing
against the coin, given it the necessary support, a guard, fixed independently of
the slot and directly over the entrance to the money box, covers enough of the
bottom or outlet end, of the slot to prevent the escape of the particular size of
coin it is necessary to employ. But a coin of smaller size will not be obstructed
by the guard, and will fall at once through the slot into the money box.
When the pusher is operated its pressure against the coin is sufficient to main-
tain the latter in position after the slot has been moved away from the supporting
guard, but in the event of any attempt being made to withdraw the pusher,
before the proper point has been reached, the coin will at once fall through
the slot into the money box. When however the pusher has moved the slot
and pawl the required distance, and is then withdrawn, ever so little, the pressure
upon the coin being relaxed the latter will fall into the money box and be no
longer available to give power to the pusher.
In some cases it may be desirable to reverse the action, by placing the pawl
the opposite way & so constructing the teeth of the prepayment wheel that
they have the opposite angle. In this case the operation of the pawl upon the
wheel is deferred till the pawl reaches the end of its journey and begins to
return to its normal position. The inward or forward movement of the pusher
produces no effect on the prepayment wheel because the pawl passes over the
teeth and cannot gear into them till it begins to move back.
In this reverse
action, the price changing platform may either support the pawl, so as to keep
it out of contact with the teeth, at the beginning or at the end of its forward
journey. Whether placed at the beginning or at the end of the forward journey
of the pawl, the platform will regulate the travel of the wheel in proportion
to the number of teeth it exposes to, or protects from, the action of the pawl.
But, if the price changing platform be placed at the beginning of the forward
movement serves the useful purpose of keeping the pawl out of contact with

page_text: the teeth except when it is being operated by the pusher. The other plan of
placing the platform, at the end of the forward journey, has not, this advantage,
and requires the addition of a platform, or "rest," to support the pawl on its
return to the normal position. As in the direct action, so also in the reverse
action, the return of the pawl, the slot, & the pusher, may be effected either by
springs or by hand, as already described.
Another part of this invention consists of a new method of adapting the
prepayment mechanism to changes in the price of gas. It will be noticed, that
the length of travel given to the pusher determines the distance the pawl will
traverse, and, consequently, the extent of the movement it will give to the
prepayment wheel. I propose therefore, to place an adjusting arrangement on
the pusher, which, by being operated, will increase, or decrease, the travel, and
so alter the movement the pusher gives to the wheel. A pointer, or indicator,
combined with a scale, will be provided, to make the change, when necessary,
a very simple operation.
In some instances a "stop" may be employed, instead of a valve, to terminate
the supply of gas by offering obstruction to the progress of the mechanism of the
meter. For this purpose, a "stop lever" may be employed under the control of a
grooved disc, or band, having a "notch," or opening, in it, or else of an arm
projecting from the prepayment shaft. In some cases the stop lever, or else the
arm, may require to be jointed, that it may yield in one direction, and offer an
obstruction in the other.
It is desirable to modify the force, which might be, exerted upon the pushing
rod, by means of a spiral screw arrangement through which the rod is made to pass.
prefer that the tube, which forms the spiral screw, should itself revolve by the
action in the screw groove of the pin of the pusher rod, because, in this case, the
pusher rod does not turn and therefore has no circular movement against the coin.
But, in some circumstances, the rod may revolve and the screw tube be fixed in
which case the end of the rod should be "tipped" with a pivoted end which will
remain steady whilst the pusher rod revolves.
1 propose, in some instances, to add a "turnstile" to the slot passage of the index
box roof, in order to prevent a coin, with a string attached to it, being maintaine
in position for fraudulent purposes. The turnstile consists of a circular slot just
large enough to accomodate the coin loosely, and having an opening in the edge
through which the coin may be passed. This slot is capable of revolving some
distance within the outer casing which contains it, and this outer casing has two
openings, one in the edge, and one in the bottom. The latter opening covers the
slot passage of the index box roof. In the normal position the revolving slot has
its inlet opening opposite the inlet opening of the outer casing, but, when the coin
has been inserted, the circular slot has to be moved round till its opening corre-
sponds with the outlet opening of the outer casing, which latter being directly over
the slot passage of the index box roof causes the coin to drop into the travelling
slot of the prepayment mechanism.
The double stuffing box arrangement, herein-before described, may be applied to
non-prepayment gas meters. In dry meters, for example, it may be used to enable
the separate enclosure for the valves to be dispensed with, by boxing in the index
in place of the valves, and superseding the usual vertical stuffing box on the valve
crank by a horizontal double stuffing box on the driving shaft, where it enters the
index enclosure. When hitherto, such an arrangement has been attempted the
result has been unsatisfactory, because ordinary stuffing boxes in the horizontal
position, are very liable to leak. The double stuffing box, however, is free from
this objection, & may, in the circumstances described, be employed with advantage.
With regard to the application of double stuffing boxes to non-prepayment wet
meters, it will be found advantageous to employ them in most of those cases in
which it has been usual to have single stuffing boxes in the horizontal position.
Toca L... of Daly 1801

page_text: COMPLETE SPECIFICATION.
Improvements in Prepayment Gas Meters, applicable, in part, also
to Non-prepayment Meters.
I, WILLIAM COWAN of Buccleuch Street Works, Edinburgh, in the County of
Midlothian North Britain, Gas Apparatus Manufacturer do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
This invention which relates to improvements in prepayment gas meters of the
coin freed type and in part applicable to non-prepayment gas meters consists of
improvements in and modifications of as well as of additions to my previous invention
No. 11537 of 23rd July 1890, and for which Letters Patent have been duly
granted.
One part of my present invention is an improved method of keeping the lever
opening in the side of the supplementary valve box gas tight and this applies to all
the forms of prepayment meters mentioned in my said former Specification and is
also applicable to non-prepayment meters.
Another part of my present invention has reference only or chiefly to the coin
form of prepayment meters as described in my said former Specification. The
present improvements like those of my previous invention apply both to wet and
dry gas meters.
But in order that my said invention may be readily understood and easily carried
into effect, will proceed to describe the same with reference to the annexed
explanatory sheets of drawings, throughont which the same reference letters denote
similar parts.
In lieu of employing a ground plug or an indiarubber or other flexible sleeve on
the axle of the supplementary valve's lever, I employ a double stuffing box arrange-
ment as is shown in section in Figure; the said arrangement consisting of the two
stuffing boxes e³, e, having an air tight chamber & between them which in some
cases may be filled with fatty or waxy material not liable to liquify at moderate
temperatures. One of these stuffing boxes I fix in the wall of the valve box and
surroned or enclose it outside the valve box by the chamber e which is closed at
its other extremity, and made gas tight by means of the other stuffing box e,
through which as well as through the other stuffling box e the axle of the valve's
lever passes. The valve box is thus protected from any escape of gas through the
lever opening by the intervention between it and the atmosphere of the two stuffing
boxes e, with the air tight chamber e between them. In order however to
increase the security thus afforded this chamber or tube e may be filled through its
opening which is provided with a screwed cap e8 with some fatty or waxy material
as already described.
I shall now refer to those improvements which are applicable only or chiefly to
the coin form of my prepayment meters, a few modifications of which I have shown
in part end elevation, part sectional elevation and part plan Figures 2, 3 and 4,
part sectional elevations Figures 5, 6, 7 and 8 part end elevation Figure 9, and
part plans Figures 10 and 11 of the annexed drawings.
In this invention dispense with most of the mechanism for discharging the coin
into the money box and for driving the pawl P of the prepayment wheel N which
was described in my said previous Specification and I substitute therefor more
simple means for effecting these purposes. The arrangement of the index and the
prepayment wheel, together with the means employed for opening, keeping open
and closing the supplementary valve, and also the price changing platform and its
appendages will be practically the same as is described in my said previous
Specification and as is shown more particularly in the accompanying drawings
Figures 8 and 10.
this invention the slot r into which the coin is dropped is formed in a

page_text: moveable slot piece R which is joined or linked at its side or end on to the pawl P
of the prepayment wheel N. And the slot piece R will also be joined at its other
side or end to near the extremity of the pusher rod 3, so that all three, pusher,
slot piece and pawl, will move forward and return backward together. But in
order to make this united action entirely dependent on the presence of the coin in
the slot an opening is made through the slot and through this opening the pusher
will pass unimpeded and without result if no coin be present. But in the event of
a coin being in the slot the opening referred to is closed or obstructed with the
result that the pusher in moving carries with it the slot piece the coin and the pawl
and so drives forward the prepayment wheel.
1'
on
In some instances, as is shown in Figures 2, 3, 4, 7, 8, 10 and 11 of the drawings,
the slot may be placed at right angles to the pushers and pawl P, and in this
case the opening will be right through its two sides and in such a position that
when a coin is present the pushers will act upon the centre or nearly the centre of
the coin. When the slot is so placed it requires to be kept sufficiently far away
from the pawl P, to allow the pusher the full length of its travel before it would
reach the pawl P, supposing no coin to be present. The opening in the slot
the side of the slot piece R nearest the pawl P is therefore provided with a tube R¹
or else two or more rods extending out to the pawl P, and to which the pawl P_is
jointed or pivoted in such a manner that it is practically one with the slot piece R.
The side of the slot piece R which is next the pusher 2 is also furnished with a
tube R or two or more rods and through these the end of the pusher 2 passes into
the slot hole. In order to prevent the backward action of the pushers taking
place without a corresponding action of the slot piece and pawl I form or provide
the tube R or the rods with an annular flange which engages with a smaller
annular flange on the pusher s², or I may employ suitable pins or projections
in lieu of said flanges. Hence the pusher not only moves the slot piece and
pawl inwards but when withdrawn brings them back to their normal position
without the aid of springs or such like, though in certain cases if desired springs
may be employed.
In some instances the slot may be placed endways as shown in Figures 5
and 6, that is in the line of the pushers and pawl P. In this case the opening is
through the end of the slot piece R next the pushers and the centre of the
edge of the coin is pressed upon when the pusher 2 is advanced as in Figure 6.
In this latter arrangement no tube or rods between the slot piece R and the pawl P
are usually necessary, because the diameter of the coin from edge to edge is
generally sufficient to allow the ineffective travel of the pusher 3 within the slot "
itself without the slot piece being provided with any tubular or other projections.
The said slot piece R which is capable of a forward and backward movement is
suitably guided in brackets secured to the inside of the index box d, and it is so
placed that when in its normal position the upper or inlet end of the slot ris
immediately under a corresponding slot opening R³ formed in a fixed guard plate R
whose opening R³ is immediately under the usual opening or slot in the cover of
the index box, the said guard plate R being for the purpose of preventing the coin
from being surreptitiously withdrawn after the pusher has been operated this being
assisted by the tail piece or plate R³ formed on the said slot piece R. The said
slots are so arranged that on a coin being passed through the outer one it then
passes through slot R³ into the main slot in which position it is held until the
pushers has by pressing against the coin given it the necessary support, by an
independently fixed guard, which may take the form of one or more pins which
are mounted directly over the entrance to the money box and so cover enough of
the bottom or outlet eud of the slot to prevent the escape of the particular size of
coin it is necessary to employ. But a coin of smaller size will not be obstructed by
the said guard but will fall at once through the slot into the money box. When
the pusher is operated, by being pressed inwards, its pressure against the coin is
suflicient to maintain the said coin in position after the slot has been moved away
from the supporting guard or pins r', but in the event of any attempt being made

page_text: to withdraw the pusher and hence relax the pressure of same on the coin before
the proper point has been reached the coin will at once fall through the slot into
the money box. When however the pushers has moved the slot piccc R and
pawl, the required distance and is then withdrawn ever so little, the pressure
upon the coin is then relaxed and the coin then falls into the money box and is no
longer available to give power to the pusher s².
In some cases it may be desirable to reverse the action by placing the pawl the
opposite way and so constructing the teeth of the prepayment wheel that they have
the opposite angle. In this case the operation of the pawl P on the wheel N
is deferred till the pawl P reaches the end of its journey and begins to return to its
normal position. The inward or forward movement of the said pawl P thus
produces no effect on the prepayment wheel N because the said pawl passes over
the teeth and does not gear into them till it begins to move back. In this reverse
action the price changing platform may either support the pawl so as to keep it out
of contact with the teeth at the beginning or at the end of its forward journey.
Whether placed, at the beginning or at the end of the forward journey of the pawl
the platform will regulate the travel of the wheel in proportion to the number of
teeth it exposes to or protects from the action of the pawl. But if the price
changing platform be placed at the beginning of the forward movement it serves
the purpose of keeping the pawl out of action with the teeth except when it is
operated by the pusher. The other plan of placing the platform at the end of the
forward journey has not this advantage and requires the addition of a platform or
6: rest to support the pawl during its return to its normal position. As in the
direct action so also in the reverse action the return of the pawl, the slot and the
pusher may be effected either by springs or by hand as already described.
with
It may sometimes happen, either accidentally or intentionally, that a coin coated
over with fatty or other adhesive material may be passed into the slot and be
retained there by adhesion between it and the surface, within the said slot
which it is in contact. In order to prevent such an occurrence and a fraudulent use
of such a possibility the slot may be ribbed or provided with two or more ribs
Figures 8, 10 and 11, or it may be pins so as to reduce the contact between the coin
and the slot to the least possible amount of touching surface as shown.
Another part of this invention consists of a new method of adapting the prepay-
ment mechanism to changes in the price of gas. It will be noticed that the length
of travel given to the pusher 2 determines the distance the pawl P will traverse
and consequently the extent of the movement it will give to the prepayment
wheel N. I therefore provide the said pusher s with an adjusting arrangement W
Figures 2, 3 and 4 which on being operated will increase or decrease the travel and
so alter the movement the pusher gives to the wheel N which in this case has a
stationary platform v.
The said adjusting arrangement W is composed of an adjustable screwed nut
accessible to the gas official only and which may be screwed in or out of the screwed
boss of the index case, the exact distance being regulated on the scale by
means of the pointer which is geared by means of the spur pinion w with a spur
rack formed on the end of the pusher and so makes the change a very simple
operation.
As a modification of the foregoing I may form the price adjusting arrangement W
as shown in Figure 7, that is I form the adjusting screw was the one end of the
rack and cause it to be adjusted in the screwed bracket in lieu of the boss w
in which case the end of the adjusting screw will be advanced to or receded
from and so caused to act upon the front end of the slot piece's extension R¹, and so
regulate its travel. The platform is also in this instance stationary.
じ
In some instances a "stop" may be employed instead of a valve to terminate the
supply of gas by offering an obstruction to the progress of the meter's mechanism.
For this purpose a "stop lever" may be employed under the control of a grooved
disc or band having a notch or opening in it, or else of an arm projecting from
the prepayment wheel. In some cases the stop lever or the arm may require

page_text: to be jointed so that it may yield in one direction and offer an obstruction in the
other.
It is desirable in some cases to modify the force which might be exerted on the
pushers by means of a spiral screw arrangement as shown at X Figures 7, 8, 9
and 10, through which the pusher is made to pass. The said arrangement X is
composed of a tube a having a spiral groove . and which is connected to and
revolved by an outside handle so as to cause the pusher to be moved
along by means of the pin 3 working in the said groove in which case
the pusher does not revolve and therefore has no circular movement against the
coin. But if desired the rod or pushers may be caused to revolve and the screw tube
be fixed, in which case the end of the pusher would be tipped with a pivotted end
which will remain steady whilst the pusher rod revolves.
My said invention also relates to the addition of a turnstile Y, Figures 12, 13
and 14 to the slot passage of the index box roof in order to prevent a coin with a
string attached to it being maintained in position for fraudulent purposes.
The
said turnstile Y consists of a circular slot y, large enough to accommodate the coin
loosely and having an opening y' in its edge through which the coin is passed.
This slot y is capable of revolving some distance within its outer casing, which
has two openings one being in its edge, and the other in its bottom or sole
plate. The latter opening covers the slot passage of the index box. In the
normal position the revolving slot has its opening yopposite the opening y, but
when the coin has been inserted the circular slot is moved round by its handle y
till its opening corresponds with the opening ', and so allows the coin to fall into
the slot of the prepayment mechanism. Or as is shown in Figure 15 I may
modify the said turnstile Y and form its slot y as a hinged or centred slow, so that
on a coin being put in the same when in its normal position as shown by dotted lines
it would then be pressed by the fingers into the position shown and so allow the
coin to drop through its opening into the main slot r. Or as is shown in section
Figures 16 and 171 may form the said turnstile Y as a square slot capable of
being moved through a quarter of a circle by means of a suitable handle which
may be mounted on the outer end of its pivoty or guide pin so that on a coin
being placed in the said slot y through the opening y³ of outer casc as in
Figure 16, and the handle turned it carries the coin down the inclined ridge y, till
it reaches the opening y' and passes into the main slot r. The said turnstile Y is
also provided with an extra opening y at its other side through which unsuitable
coins may be ejected, this opening being obstructed by means of the drop pin y
when the sloty is not.in its normal position as shown in Figure 17..
The double stuffing box arrangement hereinbefore described and shown in Figure 1
may be applied to non-prepayment gas meters. In dry meters for example it may
be used to enable the separate enclosure for the valves to be dispensed with by
boxing in the index in place of the valves and superseding the usual vertical stuffing
box on the valve crank by a horizontal double stuffing box on the driving shaft
where it enters the index enclosure. When hitherto such an arrangement has been
attempted the result has been unsatisfactory because ordinary stuffing boxes in the
horizontal position are very liable to leak. The double stuffing box as shown in
Figure 1, however, is free from this objection and may in the circumstances
described be employed with advantage. With regard to the application of double
stuffing boxes to non-prepayment wet gas meters it will be found advantageous to
employ them in most of those cases in which it has been usual to have single stuffing
boxes in the horizontal position.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, declare that what I
claim is :-
1st. In prepayment and non-prepayment wet or dry gas meters the double stuffing
box substantially as and for the purposes hereinbefore described and shown in
Figure 1 of the accompanying drawings.

page_text: 2nd. In prepayment gas meters the arrangement of the pawl P, slot piece R,
slot r, and pusher whereby the said parts are only acted upon jointly by the
intervention of a coin when the pusher is moved forwards, and are also acted upon
jointly by means of the collars and flanges and their pivoted connections without
the intervention of a coin when the pusher is returned to its normal position,
all substantially as and for the purposes hereinbefore described and shown in
Figures 2, 3, 4, 5, 6, 7, 8, and 10 of the accompanying drawings.
3rd. In prepayment gas meters the moving slot piece R, having its slot r, placed
edgeways so that the slot piece, slot and pawl are moved forward or advanced by
the pressure of the pusher 2 upon the edge of the coin and brought back after the
coin has been dropped by the collar and flange or pins and pivoted connections
between the pusher, slot and pawl, substantially as hereinbefore described and
shown in Figures 5 and 6 of the accompanying drawings.
4th. In prepayment gas meters coin slots and slot picces which are capable of
being moved forward only when a coin is in the slot and are unaffected by the
forward movement of the pusher in the absence of a coin substantially as herein-
before described and shown in Figures 2 to 10 inclusive of the accompanying
drawings.
5th. In prepayment gas meters the price changing adjusting arrangements W
substantially as and for the purposes hereinbefore described and shown in Figures 2,
3, 4 and 7 of the accompanying drawings.
6th. In prepayment gas meters the spiral screw arrangement X substantially as
and for the purposes hereinbefore described and shown in Figures 7, 8, 9 and 10 of
the accompanying drawings.
7th. In prepayment gas meters the pusher to support the coin in the slot so that
on the pusher being moved back, after having advanced the slot beyond the fixed
rest or guard tbe coin at once falls into the money box, and so makes the fraudulent
action of the pusher known as pumping impossible, substantially as herein before
described and shown in Figures 2 to 10 inclusive of the accompanying drawings.
8th. In prepayment gas meters, the turnstiles all substantially as and for the
purposes hereinbefore described and shown in Figures 12, 13, 14, 15, 16, and 17, of
the accompanying drawings.
Dated this 26th day of November 1891.
JOHNSONS,
115, St. Vincent Street, Glasgow, Applicant's Agents.