IMPROVEMENTS IN MOTORS FOR TRAMWAY CARS, TRACTION ENGINES, LATHES, AND OTHER MACHINERY
Year: 1876

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for the Invention of "IMPROVEMENTS IN
MOTORS FOR TRAMWAY CARS, TRACTION ENGINES, LATHES, AND OTHER
MACHINERY." A communication from abroad by Anson Perry Thayer, of the
City County and State of New York, United States of America.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 17th February 1876.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent. "IMPROVEMENTS IN MOTORS FOR TRAMWAY CARS, TRACTION
ENGINES, LATHES, AND OTHER MACHINERY."
This Invention consists in a steam engine or other motor, a pump, a pressure
wheel or rotary engine, and in some cases a liquid reservoir, combined and arranged
to transmit power by forcing air or liquid by the pump through the pressure
wheel, and in the case of liquid being used back into the reservoir from which the
pump takes it, the pressure wheel being geared with the wheel or wheels of the car
or wagon or other machinery to be driven in any suitable way for turning them ;
and the Invention also comprises another pressure wheel receiving motion from the
pump in the same way, and being geared with the fifth wheel or other equivalent
part of the running gear of a wagon or traction engine or road wagon, so as to
utilize the motive power for steering, guiding, or directing the vehicle on a common
road.
The essential objects of the Invention are,-
First. A more simple and direct method of reducing motion from high to low
speed.
And, Second. A simple method of varying the speed of the object to be driven
than the inethod now employed.
The machine is specially intended for driving street cars and traction engines,
for which it is desirable to have a very small, light, and quick running engine, in
order that its weight and the strength and weight of parts on which it is mounted
may be as small as possible, and at the same time they require the motion to be
greatly reduced at the point of application, as the wheels to which the power must

page_text: be applied run, comparatively slow, so that a train of wheels for reducing the
motion, whether cogged or working. with belts, would require too much space, weight
of material and strength, and weight of supporting devices, whereas with this
machine any required amount of reduction is obtained merely by making the
volume capacity of the pump as much smaller than that of the pressure wheel as the
required reduction of the speed of the latter to the former. But the most essential
advantage of its use as a notor for cars and road wagons and other machinery
requiring variable motion lies in its facility for varying the speed of the pressure
wheel, and thereby the speed of the car or wagon wheel, relatively to the speed of
the engine and pump, which is accomplished by varying (diminishing or increasing)
the volume of air or liquid which the pump is permitted to force through the
pressure wheel in a given time or per revolution of the pump. The object of thus
varying the relative speed of the driving engine and the car or wagon wheels is to
enable the engine to run just as fast when the car or wagon has to go slow, by
reason of the greater resistance of up grades or bad roads as when it goes fast on a
level or down grade, which an engine geared positively or in the ordinary way
cannot do, the consequence of which is that when the car mects the greatest resist-
ance and has to go slow, the efficiency of the engine is diminished in the direct
proportion of its reduction in speed. This is consider to be the main difficulty in
the way of the use of steam on common roads, because it requires the capacity of
the engine and boiler to be five or more times to drive the machine up hill than is
needed on the level, and this excess makes the steam power too expensive to
compete with horse power, and besides it loads the waggon too much.
Different trains of transmitting gears, that is to say, differential gears may of
course be used but they are too heavy, cumbersome, and expensive, and at best only
two or at most three changes can be had within practical limits, and however they
are contrived, the machine must be stopped to shift the gears, for cone pulleys and a
belt will not do for this heavy labour; and another contrivance consisting of a
pawl, lever, and pawl to work a ratchet wheel on the hub of the wagon or car
wheel, the connecting rod of the engine being connected so as to shift along the
lever, which has been tried, will not do, because the sudden taking hold and letting
go of the pawl shocks and jars the machine; the power only acts when the lever is
going one way and not the other, and the pawl is very noisy, rattling over the teeth
of the ratchet wheel.
In the improved motor of this Invention this variation of the car or wagon wheel
in speed relatively to the engine is effected merely by turning a cock or moving a
valve in the pipe supplying the pump, if a rotary pump is used or varying the
throw of the piston by a link if a reciprocating pump is used, so as to diminish the
quantity of air or liquid when the speed of the car or wagon must decease and
increase it when the speed is to increase. For the maximum speed of the car or
wagon the full capacity of the pump will be employed, and the volume will be
diminished just in the proportion that the speed is diminished.
Whatever volume of liquid or air is transmitted will be impelled by the full
power of the engine by which the pump is driven, and there will be again in effect
on the pressure wheel, and consequently on the car or wagon wheel corresponding
to its loss of speed, so that practically the leverage of the engine increases as the
speed of the car or wagon diminishes. Thus a steam engine having only capacity
to drive the car or wagon up to the required speed on a level will be enabled to
exert its maximum force on the grade, no matter how much the speed of the
vehicle be diminished, and the changes of the speed of the one to the other may be
graduated to each other under all conditions at the will of the engineer and without
stopping the machine.
The pressure wheels by which the power is applied both for propelling and
steering will be constructed for reversing to run both forward and backward and
have reversing valves; and the impelling fluid will be shut off from the steering
wheel when running in a straight course, that wheel only being required to turn
when the course of the vehicle is to be changed. When water or other liquid

page_text: is used it will exhaust back into the reservoir from this wheel the same as from the
other.
The first part of the Invention is applicable for driving turning lathes, hoisting
drums, and other machinery requiring to be worked at different speeds, and
particularly such as requires slow and powerful motion.
As applied to a tram car there is a steam generator on the platform, together with
a pair of small, light, and quick running steam engines, turning a shaft which
oxtends to the middle of the space between the fore and hind wheels, where it
connects with a rotary pump, which may in practice be of any approved kind, but
which in this case is supposed of that kind of which the forcing apparatus is like
two cog wheels with very long teeth meshing together. Above the pump is a
reservoir for the liquid to be used, which may be water, oil; glycerine, or dextrine,
or air may be used, which will not need a reservoir. The pump and this reservoir
are connected by a pipe, through which the liquid flows into the pump, and in
which is a cock or any other device for throttling the liquid or air to regulate the
volume admitted to the pump. This cock or valve has a rod connected with a
hand lever on the engineer's platform, for opening and closing as the liquid is to be
increased or diminished.
The pump is constructed in a series of independent sections or chambers, which
are closed one after another and opened in the same way by the valve to vary the
volume of water or other fluid. The pump is connected by pipes with a pressure
wheel or rotary engine on each wheel axle, and these pressure wheels have their
exhausts connected with the reservoir by pipes, so that the liquid drawn from the
reservoir by the pump and forced through the wheels returns to the reservoir after
doing its work, and goes on working over and over as one of the elements of the
machine, and being the means of transmitting the power expended on the pump to
the car wheels.
These rotary engines may be of any kind, but in this case are a hollow cylinder
fitted on the axle by stuffing boxes, so that the axle to which the hub having
the pistons is attached may revolve, and the two engines are connected by a bar
entering a socket of each wheel to prevent them from turning. The reversing
valve of both wheels is connected to a rod, which extends to the engineer's stand
and is connected to a reversing lever, by which the power can be applied to drive
the car in either direction. In practice the reversing valve will be arranged so that
it cannot rise, and also so that it can close that one of the two ports through which
the fluid exhausts more than the other, in order that it may be used to stop or
brake the car by shutting off the escape of the air or fluid from the wheel without
interrupting the inlet.
A rotary engine may be used as the driving engine, and only one pressure wheel,
said wheel being attached to the under side of the car bottom between the axles,
and geared to them by chains and chain pulleys, and in this case the same pump
that drives the car is also made to feed the boiler through a pipe which is supplied
by certain sections of the pump, which will take the water from the feed water
tanks, which I propose to locate in the corners of the car under the seats, and exhaust
the steam into them to utilize the heat for warming the car in cold weather, and to
lessen the amount of steam discharged into the air as much as possible by con-
densing it. The force and noise of the exhaust is also considerably reduced by this
plan.
To prevent the pump working against a vacumn when liquid is used and the full
supply is not admitted, a small air pipe may open into the pump from a height
sufficiently above the level of the liquid in the reservoir to prevent the liquid from
running out when the pump is stopped.
This improved motor is applicable for driving all kinds of machinery subject to
material variations of the load or resistance.
In the application of this motive apparatus to road waggons or traction engines a
pressure wheel will be used to each wagon wheel to be employed for driving the
wagon or traction engine, and said wheels will turn loose on the axle and inde-

page_text: pendently of each other. The water or other fluid will be applied to them from one
pump, and will return to the same box. The pressure wheels will couple on to the
hubs of the driving wheels in any approved way, or they may be located on the
frame or platform of the wagon, so as to gear by chain pulleys with chain pulleys
attached to the spokes of the driving wheels. By using a pressure wheel to each
driving wheel, and having the latter turn loose on the axle, the driving wheels are free
to run independently of each other in going around curves and the like, and they
will at the same time have the power applied all the same as when going in a
straight line, the one which goes outside taking more of the fluid than the other.
Pressure wheels may be applied to the front wheels by using flexible connecting
pipes, and thus obtain the traction of all the wheels. A pressure wheel is employed
for steering the road wagon; it gears by a worm with a toothed wheel to be so
connected to the vibrating axle or parts of the running gear, say, the "fifth" wheel
connected to it, while the pressure wheel and worm are attached to the platform or
other part connected to it, so that the turning of the engine one way or the other
will swing the axle correspondingly. This wheel receives motion from the pump
by liquid forced through a pipe to it same as to the other. pressure wheels, and
returning similarly by another pipe to the box, and it will have a reversing valve and
lever same as the other pressure wheels for causing it to run in either direction.
For obtaining the same results by the use of a reciprocating pump the pump
will be geared to a crank shaft by a link and eccentrics, and the link will have a
hand wheel and screw or other contrivance for shifting it to lengthen or shorten the
throw of the pump piston for varying the volume of air or liquid transmitted, the
link motion serving in this case the same purpose that the throttle is used for
in the other, and producing the same effect, the long throw giving the maximum
volume for the maximum speed, and the shorter throws giving volumes corre-
sponding to their length for corresponding speeds, and having increased effect on
the pressure wheel proportionate to the diminished travel of the pump piston.
It will be desirable to use an air chamber with this form of pump. In this case
there is a valve worked by a rod to shut off connection of the exhaust in case it
may be wanted to do so for a brake to stop the car.
This Invention differs from that by which air is stored up in a receiver by a com-
pressor, to be subsequently worked off in an engine by the pressure in the receiver,
in that in this plan no receiver is used for compressed air, and the pressure wheel is
worked simultaneously with and directly by the pump.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Alexander Melville Clark in the Great Seal Patent Office on the 5th August
1876.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
" IMPROVEMENTS IN MOTORS FOR TRAMWAY CARS, TRACTION
ENGINES, LATHES, AND OTHER MACHINERY." A communication from abroad by
Anson Perry Thayer, of the City, County, and State of New York, United States
of America.
This invention consists in a steam engine or other motor, a pump, a pressure
wheel, or a rotary engine, and in some cases a liquid reservoir, combined and
arranged to transmit power by forcing air or liquid by the pump through the
pressure wheel, and, in the case of liquid being used, back into the reservoir from
which the pump takes it, the pressure wheel being geared with the wheel or wheels
of the car or wagon or other machinery to be driven in any suitable way for
turning them; and the Invention also comprises another pressure wheel, receiving
motion from the pump in the same way, and being geared with the fifth wheel or

page_text: engine, or road
wagon, so as to utilize the motive power for steering, grinding, or directing the vehicle
on a common road.
The essential objects of the Invention are,-
First. A more simple and direct method of reducing motion from high to low
speed.
And, Second. A simpler method of varying the speed of the object to be driven
than the methods now employed.
The machine is specially intended for driving street cars and traction engines, for
which it is desirable to have a very small, light, and quick running engine, in order
that its weight and the strength and weight of parts on which it is mounted may be
as small as possible, and at the same time they require the motion to be greatly
reduced at the point of application as the wheels to which the power must be
applied run comparatively slow, so that a train of wheels for reducing the motion,
whether cogged or working with belts, would require too much space, weight of
material, and strength and weight of supporting devices, whereas with this machine
any required amount of reduction is obtained merely by making the volume
capacity of the pump as much smaller than that of the pressure wheel as the
required reduction of the speed of the latter to the former. But the most essential
advantage of its use as a motor for cars and road waggons, and other machinery
requiring variable motion, lies in its facility for varying the speed of the pressure
wheel, and thereby the speed of the car or wagon wheel relatively to the speed of
the engine and pump, which is accomplished by varying (diminishing or increasing)
the volume of air or liquid which the pump is permitted to force through the
pressure wheel in a given time or per revolution of the pump. The object of thus
varying the relative speed of the driving engine and the car or wagon wheels is to
enable the engine to run just as fast when the car or wagon has to go slow by
reason of the greater resistance of up grades or bad roads as when it goes fast on a
level or down grade, which an engine geared positively or in the ordinary way
cannot do, the consequence of which is that when the car meets the greatest resist-
ance and has to go slow the efficiency of the engine is diminished in the direct pro-
portion of its reduction in speed. This I consider to be the main difficulty in the
way of the use of steam on common roads, because it requires the capacity of the
engine and boiler to be five or more times to drive the engine up hill than is needed
on the level, and this excess makes the steam power too expensive to compete with
horse power, and besides it loads the wagon too much.
Different trains of transmitting gears, that is to say differential gears, may of
course be used, but they are too heavy, cumbersome, and expensive, and at best only
two or at most three changes can be had within practical limits, and however they
are contrived the machine must be stopped to shift the gears, for cone pulleys and a
belt will not do for this heavy labor; and another contrivance, consisting of a pawl
lever and pawl to work a ratchet wheel on the hub of the wagon or car wheel, the
connecting rod of the engine being connected so as to shift along the lever, which
has been tried, will not do, because the sudden taking hold and letting go of the
pawl shocks and jars the machine; the power only acts when the lever is going one.
way and not the other, and the pawl is very noisy, rattling over the teeth of the
ratchet wheel.
In the present motor this variation of the car or wagon wheel in speed relatively
to the engine is effected merely by turning a cock or moving a valve in the pipe,
supplying the pump if a rotary pump is used, or varying the throw of the piston
by a link if a reciprocating pump is used, so as to diminish the quantity of air or
liquid when the speed of the car or wagon must decrease and increase it when the
speed is to increase. For the maximum speed of the car or wagon the full capacity
of the pump will be employed, and the volume will be diminished just in the
proportion that the speed is diminished.
Whatever volume of liquid or air is transmitted will be impelled by the full
power of the engine by which the pump is driven, and there will be a gain in effect

page_text: on the pressure wheel, and consequently on the car or wagon wheel, corresponding to
its loss of speed, so that practically the leverage of the engine increases as the
speed of the car or waggon diminishes. Thus a steam engine, having only capacity
to drive the car or wagon up to the required speed on a level, will be enabled to
exert its maximum force on the grade, no matter how much the speed of the vehicle
may be diminished, and the changes of the speed of the one to the other may be
graduated to each other under all conditions at the will of the engineer, and
without stopping the machine.
The pressure wheels by which the power is applied, both for propelling and
steering, will be constructed for reversing, to run both forward and backward, and
have reversing valves, and the impelling fluid will be shut off from the steering
wheel when running in a straight course, that wheel only being required to turn
when the course of the vehicle is to be changed. When water or other liquid is
used it will exhaust back into the reservoir from this wheel the same as from the
others.
The first part of the Invention is applicable for driving turning lathes, hoisting
drums, and other machinery requiring to be worked at different speeds, and particu-
larly such as require slow and powerful motion.
Figure 1 is a longitudinal sectional elevation of a street car, with the improved
motor applied in one of the various forms in which it may be used; Figure 2 is a
plan of Figure 1.
Figure 3 is another longitudinal sectional clevation of street car, showing another
form in which it may be used; Figure 4 is a plan of Figure 3.
Figure 5 is a front elevation of a road waggon, and Figure 6 is partly a plan and
partly a horizontal section of the road wagon inverted.
Figure 7 is a sectional elevation, and Figure 8 a plan of a modification of the
Invention, showing the application of a reciprocating pump.
Similar letters of
reference indicate corresponding parts.
A represents the platform; B, the end; C, the side; D, the bottom or floor; and
E, one of the seats of an ordinary street or horse car. F is a steam generator,
standing on the platform, by the side of which is a pair of small, light, and quick
running steam engines G, running say five hundred revolutions per minute, and
turning the shaft H, which extends along under the car seat to the middle of the
space between the fore and hind wheels where it connects with a rotary pump I,
which may in practice be of any approved kind, but which in this case is repre-
sented as of that kind of which the forcing apparatus is like two cog wheels with
very long teeth meshing together. Above the pump is a reservoir J of the liquid
to be used, which may be water, oil, glycerine, or dextrine, or air may be used,
which will not need a reservoir; the pump and this reservoir are connected by a
pipe K, through which the liquid flows into the pump, and in which is a cock L,
valve gate, or any other device for throttling the liquid or air to regulate the volume
admitted to the pump. This cock or valve has, a rod M extending from it to the
engineer's stand on the platform, where it connects with a hand lever N for opening
and closing as the liquid is to be increased or diminished.
The pump is constructed in a series of independent sections or chambers I', which
are closed. one after another and opened in the same way by the valve L to vary
the volume of water or other fluid. The pump is connected by pipes O, with a
pressure wheel or rotary engine P, on each axle Q, and these pressure wheels have
their exhausts connected with the reservoir by pipes R, so that the liquid drawn
from the reservoir by the pump and forced through the wheels returns to the
reservoir after doing its work, and goes on working over and over as one of the
elements of the machine, and being the means of transmitting the power expended
on the pump to the car wheels.
.. These rotary engines may be of any kind, but in this case are represented as a.

page_text: hollow cylinder a, fitted on the axle by stuffing boxes b, so that the axle to which
the hub d, having the pistons e, is attached may revolve, and the two engines are
connected by a bar fentering a socket g of each wheel to prevent them from turn-
ing. is the abutment which closes the passage from port to port; i, the ports;
j, the exhaust; and, a reversing valve. The reversing valve of both wheels is
connected to the rod l, which extends to the engineer's stand, and is connected to
the reversing lever m, by which the power can be applied to drive the car in either
direction. In practice the valve & will be arranged so that it cannot rise, and also
so that it can close the port i, through which the fluid exhausts more than the other
in order that it may be used to stop or brake the car by shutting off the escape of
the air or fluid from the wheel without interrupting the inlet, which arrangement
is clearly represented in Figure 3.
In Figures 3 and 4 a rotary engine G¹ is used as the driving engine, and only one
pressure wheel P is used, said wheel being attached to the under side of the car
bottoin D between the axles and geared to them by chains P, and chain pulleys P³,
and in this case the same pump that drives the car is also made to feed the boiler
through a pipe I2, which is supplied by sections I³, of the pump which will take.
the water from the feed water tanks J, which I propose to locate in the corners of
the car under the seats, and exhaust the steam into them by pipes ¹ to utilize the
heat for warming the car in cold weather, and to lessen the amount of steam dis-
charged into the air as much as possible by condensing it. The force and noise of
the exhaust is also considerably reduced by this plan. The d water from the
boiler will be regulated by the valve N¹, rod N, and hand lever N³.
The maximum speed at any time required of the pressure wheels P when applied
to the driving of a street car is one hundred revolutions per minute, and the
minimum about twenty. If the pump is to run five hundred as above stated its
capacity will be one to five of that of the wheels P.
When a liquid substance is used for transmitting the power a good size for the
pump would be a capacity of twenty cubic inches per revolution, which would
require one hundred inches of capacity for the pressure wheels P. In this case
the throttle L should be adapted to close the pipe so as only to admit four
inches for one revolution of the pump when the car wheels are to slow down
to twenty revolutions.
To prevent the pump from working against a vacuum when liquid is used, and
the full supply is not admitted, a small air pipe p may open into the pump from a
height sufficiently above the level of the liquid in the reservoir to prevent the
liquid from running out when the pump is stopped. The air thus admitted will
be forced along with the liquid through the pressure wheels, but its great com-
pressibility will prevent its volume from being objectionable; whatever volume it
does make may be compensated for by throttling the supply pipe a little more. The
admission of air in this way will not prevent the pump from taking all the liquid
that will pass through the throttle because the reservoir will be so high that the
liquid will flow in by gravity to the exclusion of the air, the air pipe p may there-
fore always be open to the atmosphere, and will need no attention in the way of
opening and closing it; it should be connected with each chamber I. The reservoir
will also be open to the atmosphere to allow the air discharging into it with the
liquid from the pressure wheels to escape freely. When air alone is used the pump
will have to work against a partial vacuum when the volume is to be diminished,
but the loss will not be material for the area will not be large, although for working
air alone the volume capacity of the pump and pressure wheels will have to be
larger than for liquid.
This improved motor is applicable for driving all kinds of machinery, subject .to
material variations of the load or resistance. In the application of this motive
apparatus to road wagons or traction engines, see Figures 5 and 6, a pressure wheel
P will be used to each wagon wheel Q₁ to be employed for driving the wagon or
traction engine, and said wheels will turn loose on the axle Q, and independently
of each other. The water or other fluid will be applied to them from one pump I,

page_text: and will return to the same box J. The pressure wheels will couple on to the hubs
of the driving wheels as at R¹, or in any approved way, or they may be located on
the frame or platform of the wagon, so as to gear by chain pulleys, with chain
pulleys attached to the spokes of the driving wheels. By using a pressure wheel
to each driving wheel, and having the latter turn loose on the axle the driving
wheels are free to run independently of each other in going around curves and the
like, and they will at the same time have the power applied all the same as when
going in a straight line, the one which goes outside taking more of the fluid than
the other. No clutch or other device for disconnecting one of the wheels or turning
curves is required as in the engines now made. Pressure wheels may be applied to
the front wheels by using flexible connecting pipes O, and thus obtain the traction
of all the wheels. The platform A³ of the truck or wagon will be arranged above
the wheels P, and the box J, pump I, and engine G¹ may be bolted to the under side
of the platform. A is the pressure wheel employed for steering the road wagon; it
gears by worm B², with a toothed wheel C, to be so connected to the vibrating
axle or parts of the running gear, say the "fifth" wheel connected to it, while
the engine A and worm B are attached to the platform or other part connected to
it, so that the turning of the engine one way or the other will swing the axle
correspondingly. This wheel receives motion from pump I by liquid forced through
pipe Ỗ to it, same as to the other pressure wheels, and returning similarly by pipe
R to the box f, and it will have a reversing valve and lever m, same as the other
pressure wheels for causing it to run in either direction.
For obtaining the same results by the use of a reciprocating pump S, Figures 7
and S, the pump will be geared to the crank shaft H by a link T, and eccentrics
2, and the link will have a hand wheel W and screw X or other contrivance for
shifting it to lengthen or shorten the throw of the pump piston for varying the
volume of air or liquid transmitted, the link motion serving in this case the same
purpose that the throttle L is used for in the other, and producing the same effect,
the long throw giving the maximum volume for the maximum speed, and the
shorter throws giving volumes corresponding to their lengths for corresponding
speeds, and having increased effect on the pressure wheel proportionate to the
diminished travel of the pump piston.
It will be desirable to use an air chamber Y with this form of pump. The rod A¹
works a valve in this case to shut off connection with the exhaust in case it may
be wanted to do so for a brake to stop the car.
This Invention differs from that by which air is stored up in a receiver by a
compressor to be subsequently worked off in an engine by the pressure in the
receiver, in that in my plan no receiver is used for compressed air, and the pressure
wheel is worked simultaneously with and directly by the pump, and I disclaim such
arrangement.
Having described the nature of the said Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is,—
1st. As a motor for propelling street cars, traction engines, omnibusses, and other
machinery, a steam engine or other motor, a pump, and a rotary pressure wheel,
arranged for forcing air or liquids through the pressure wheel directly from the
pump, and thereby producing continuous rotary motion.
2nd. The combination of a steam engine or other motor, a pump, and a rotary
pressure wheel or engine, arranged for forcing air or liquid through the pressure
wheel, and thereby producing rotary motion, and also arranged to increase or
diminish the volume of air or liquid admitted to and impelled by the pump.
3rd. The combination with a railroad car, traction engine, or road wagon of a
steam engine or other motor, a pump, and one or more pressure wheels, said pres-
sure wheels being geared with the axle or axles, wheel or wheels of the car, traction
engine, or road wagon for applying the power of the engine to drive said car,
traction engine, or road wagon.
4th. In a traction engine or road wagon impelled by a fluid or liquid substance

page_text: used to transmit the power of a steam engine or other motor to the wheel a pres-
sure wheel connected with the running gear so as to steer or guide the vehicle, and
being operated by fluid or liquid impelled by the driving engine.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Third day of August, in the year of our Lord One
thousand eight hundred and seventy-six.
A. M. CLARK. (L.S.)