IMPROVEMENTS IN FURNACES AND BOLLERS AND PARTS CONNECTED WITH THEM FOR GENERATING STEAM AND HEATING FLUIDS, AND ALSO FOR IMPROVED APPARATUS FOR REDUCING AND SHUTTING OFF STEAM AND REGULATING THE SPEED OF STEAM ENGINES
Year: 1865

page_text: · LETTERS PATENT to John Cass, of Accrington, in the County of Lancaster,
Engineer and Millwright, for the Invention of "IMPROVEMENTS IN FURNACES
AND BOLLERS AND PARTS CONNECTED WITH THEM FOR GENERATING STEAM AND
HEATING FLUIDS, AND ALSO FOR IMPROVED APPARATUS FOR REDUCING AND
SHUTTING OFF STEAM AND REGULATING THE SPEED OF STEAM ENGINES."
Sealed the 8th August 1865, and dated the 11th February 1865.
PROVISIONAL SPECIFICATION left by the said John Cass at the Office of
the Commissioners of Patents, with his Petition, on the 11th February
1865.
I, JOHN CASS, of Accrington, in the County of Lancaster, Engineer and
"IMPROVE
Millwright, do hereby declare the nature of the said Invention for
MENTS IN FURNACES AND BOILERS AND PARTS CONNECTED WITH THEM FOR GENERATING
STEAM AND HEATING FLUIDS, AND ALSO FOR IMPROVED APPARATUB FOR REDUCING AND
SHUTTING OFF STEAM AND REGULATING THE SPEED OF STEAM ENGINES," be as
follows:--
This Invention consists, firstly, in various improved arrangements of furnaces
and boilers, and modes of setting them, for the purpose of increasing their
[Price Sd.]

page_text: heating surfaces, economizing fuel, and reducing the wear and tear; secondly,
in improved modes of supplying heated air to the furnaces of boilers; thirdly,
in an improved mode of manufacturing the boilers; and fourthly, in an im-
proved reducing, regulating, or shut-off or stop valve, and parts connected
with it for reducing steam to various degrees of pressure. for regulating the
speed of the steam engine, and for shutting off steam when required.
In one arrangement of furnace 1 employ hollow fire-bars, open at each end,
and having flutes, hollows, or corrugations in their tops and sides, or I make
them fluted at the sides and plain at the tops, or plain at the sides and fluted
at the tops. At the bottom of each bar there is an aperture open to the ash-
pit, and when the length of the furnace is made by two series of bars the
apertures in the front bars lead to a hollow dead plate, and the apertures in
the back bars lead to a hollow bridge. When the length of the furnace is
formed of one series of bars, in some cases I form each bar with a partition
in the middle, having at each side an aperture open to the ash-pit, the front
aperture leading to the dead plate, and the back aperture to the bridge; but
in other cases I dispense with the partition, and use a single aperture near
the dead plate, the said aperture leading to the interior of the bar, and sup-
plying air to the bridge. I also form some bars open at one end and closed
at the other, there being simply apertures at the bottom for the admission of
air to the interior of the bars and the bridge. With those fire-bars in which
the bottom apertures are at or near the middle of the furnace, I employ a
dead plate, forming part of a box or chamber, having its bottom and sides
closed and its top formed as a grate, or perforated with holes, the current of
air for the furnace passing through the apertures to the interiors of the bars,
and through their open ends to the interior of the box or chamber, and from
thence through the grate or perforations in the dead plate to the interior of the
.furnace. When the apertures of the bars, are at the front end for supplying
air to the interiors of the bars and the hollow bridge, but not to the furnace,
the box or chamber of the dead plate must be open to the atmosphere,
and therefore in this case the box is open at the front, so that air can pass
through the fire-bars to the hollow bridge, and also through the grate or
perforations in the dead plate to the interior of the furnace, the back part of
the bottom of the box being used for supporting the bars, and for checking
the draught, and giving air to the front part of the furnace; I employ, when
required, a sliding plate or fender in the ash-pit. In connection with the
aforesaid improved fire-bars I employ a hollow bridge formed of two plates,
having at the top a grate and perforated pipes. In the front plate there is an
opening leading to the interior of the bridge, and above and below this opening

page_text: there are plates extending across the furnace, the lower plate supporting the
fire-bars at that end, and the upper plate supporting fire-bricks for preventing
the metal from burning. The air from the interiors of the fire-bars rushes.
into the hollow bridge, and passes through the grate and perforated pipes, and
thereby consumes the smoke and gives additional heat; and when required, I
attach a pipe from the ash-pit to the bottom of the hollow bridge, and place
in the pipe another pipe having a number of holes or apertures, which pipes
enable the bottom of the bridge to be cleaned, and also supplied with air.
For splitting the gases arising from combustion, and consuming them for the
production of heat and prevention of smoke, I place behind the bridge one or
more cylinders, each closed at the front by a circular or polygon-shaped cone,
either entirely colosed and separate from the bridge, or perforated with holes
and connected by a pipe to the bridge.
The foregoing arrangements are applicable to furnaces in the internal flues
of the boiler; but with slight modifications they are applied to the outside of
the bottom of the boiler, and also to the boilers of locomotives and marine
engines.
!
In one arrangement of my improved boilers I form three internal flues,
and place the furnace at the outside of the bottom and sides of the boiler.
The smoke and gases pass from the furnace to the back, then through one
flue to near the front, and then through short pipes to the other two flues to
the chimney; and instead of setting the boiler by brackets resting on the
brickwork, I set it on standards resting on the foundation, the said standards.
having grooves into which plates can be placed to form external flues when
required.
In other arrangements I fix to the shell of the boiler large tubes or
chambers, open at one end to the fire of the furnace or to the heat from an
external flue, and closed at the other end and sides to the water in the boiler,
for the purpose of reducing the bulk of water, and greatly increasing the
heating surface. These tubes or chambers are placed either between or on
each side of the longitudinal internal flues of the boiler, or used when there
are no internal flues, and in some cases they extend through the boiler in a
vertical, horizontal, or diagonal direction, and are open at both ends for the
circulation of heat. In any of the aforesaid boilers the furnaces may be placed
either in internal flues or at the bottom outside the boiler; and for improving
the draught or checking the heat of the furnace, I send a jet of steam into
the flue between the damper and the furnace. For supplying heated. air to
the furnaces, I place in the back flue leading to the chimney a pipe open at
one or both ends, and connect to it a number of pipes, one for each furnace..

page_text: Each of these pipes passes from the first-mentioned pipe, either along the side
or top of the boiler and then through the boiler to the furnace, so that the air
entering the first pipe shall become heated in the flue and in its passage, and
afterwards delivered to the fire, or passed into the take-up of the boiler; or I
employ a single or double-acting air pump for forcing air through the said
pipes, in order that it may be heated in its passage to the furnace or take-up,
the object in both cases being to return a great portion of the heat which
would otherwise pass up the chimney; and in some cases I apply these air
pumps to the exhaust pipe of the steam engine or top end of the condenser, in
order to draw off heat and vapour and pump them into the boiler or into the
furnace or take-up.
My improved mode of manufacturing the boilers consists in using plates of
sufficient length to form the entire circumference of the boiler, and instead of
overlapping the edges I bring them together as jump joints, over which I
place a longitudinal plate, and rivet it by two or more rows of rivets to the
ends of the plate. I also bring the transverse edges of the plates together as
jump joints, and hold them together by rivetting welded hoops to the exterior
or interior of the plates.
For reducing steam from high to low pressures I employ à box or
chamber, having a pipe or branch for the entry of the steam from the boiler,
and another pipe or branch for its escape to the engine or other machine, in
which it is to be employed. At or about the middle of the chamber there is a
partition having two valves and seatings, one opening to the supply and the
other to the discharge, and together acting as an equilibrium valve. The
spindles of the valves are connected to two arms of a lever, having one of its
arms also connected to the rod of a small piston working in a cylinder at the
top of the chamber, and the valve in the chamber on that side is weighted
according to the reduced pressure required.
When this valve box and valves are to be applied to regulate the speed of
the steam engine I connect the rod at the top of the aforesaid small piston to
a boss having a screwed hole, to which is fitted a screw at one end of a rod,
carrying at the other end a pulley placed between flanges on the spindle of
the steam engine governor. The aforesaid flanges are so placed that when
the balls of the governor collapse one of the flanges will be in contact with
the pulley, and give it motion so as to turn the screw and increase the opening
of the valves; but when the balls expand, the flange on the opposite side will
come in contact with the other side of the pulley, and turn it in a reverse
direction, and lessen the opening of the valves, and as the valves are more
open and give more steam when the speed is becoming too low, and less open

page_text: when the speed is becoming too great, it follows that the speed of the engine
can be regulated very efficiently.
When the said box and valves are to be used as a shut-off or stop valve the
top of the piston rod is screwed and fitted to a nut in a handle or wheel, so
that when the wheel is turned one way the valves can be pressed on their
seatings and shut off the steam, and opened, when required, by reversing the
motion of the handle or wheel.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Cass in the Great Seal Patent Office on the 11th
August 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME I, JOHN
CASS, of Accrington, in the County of Lancaster, Engineer and Millwright,
send greeting.
. WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of February, in the year of our
Lord, One thousand eight hundred and sixty-five, in the twenty-eighth year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said John Cass, Her special license that I, the said John
Cass, my executors, administrators, and assigns, or such others as I, the
said John Cass, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after 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
MENTS IN FURNACES AND BOILERS AND PARTS CONNECTED WITH THEM FOR GENERATING
STEAM AND HEATING FLUIDS, AND ALSO FOR IMPROVED APPARATUS FOR REDUCING
AND SHUTTING OFF STEAM AND REGULATING THE SPEED OF STEAM ENGINES," upon
the condition (amongst others) that I, the said John Cass, my executors or
administrators, by an instrument in writing under my, or their, or one of
their hands and seals, should particularly describe and ascertain the nature
of the said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said John Cass, do hereby declare the nature
of my said Invention, and in what manner the same is to be performed, to

page_text: be particularly described and ascertained in and by the following statement
(that is to say)-
This Invention consists, first, in various improved arrangements of furnaces
and boilers, and modes of setting them for the purpose of increasing their
heating surfaces, economizing fuel, and reducing the wear and tear; secondly,
in improved modes of supplying heated air to the furnaces of boilers; thirdly,
in improved modes of manufacturing the boilers; and, fourthly, in an improved
reducing, regulating, or shut off, or stop valve, and parts connected with it for
reducing steam to various degrees of pressure for regulating the speed of
the steam engine, and for shutting off steam when required. These improve-
ments will be clearly understood by the following detailed description thereof,
reference being had to the figures and letters on the accompanying six Sheets
of Drawings.
In Sheet 1, Fig. 1, is a longitudinal section; Fig. 2 a plan in part; and
Fig. 3 a transverse section of a two-flued boiler, made according to, and
provided with, some of my improvements. Figs. 4, 5, 6, 7, and 8 are detached
views of the fire bars; and Fig. 9 a full-sized section, shewing the mode of
joining the plates of the boiler.
In Sheet 2, Figs. 10 and 11, are longitudinal and transverse sections of a
one-flued boiler, provided with some of my improvements, and Figs. 12 and 13
are similar sections of another arrangement of my improved boilers.
In Sheet 3, Fig. 14, is a longitudinal section; Fig. 15 an end elevation;
and Figs. 16 and 17, transverse sections of a boiler, having three internal flues
and fired underneath.
In Sheet 4, Figs. 18 and 19, are longitudinal and transverse sections, and
Fig. 20, an end elevation of a two-flued boiler, made according to my im-
provements. Figs. 21 and 22 are longitudinal sections, having parts of my
improvements.
In Sheet 5, Figs. 23, 24, 25, and 26 represent my improvements connected
with locomotive boilers.
In Sheet 6, Fig. 27, is a sectional plan; Fig. 28, a sectional elevation;
and Fig. 29, an outside view, representing my improvements for reducing
steam to various degrees of pressure.
In one arrangement of furnace, I employ hollow fire bars a, Figs. 1, 2, 3,
4, 5, 6, 7, and 8, Sheet 1, in which the furnaces are in the flues. The said
fire bars are open at each end, and have flutes, hollows, or corrugations b, c, in
their tops and sides, or I make them fluted at the sides and plain at the tops,
or plain at the sides and fluted at the tops. At the bottom of each bar there is
an aperture opening to the ash-pit, as shewn at d, Figs. 1 and 5, and when the

page_text: length of the furnace is formed of one series of bars, I make, in some cases
cach bar with a partition e, Fig. 10, Sheet 2, in the middle, having at each side
an aperture, f, g, open to the ash-pit, the front aperture leading to a hollow
dead plate h, and the back aperture g to a hollow bridge i, Figs. 1, 10, and 14,
and when the length of the furnace is made by two series of bars, the
apertures in the front bars lead to the hollow dead plate, and the apertures in
the back bars lead to the hollow bridge. In Fig. 1 the partition is dispensed
with, there being only a single aperture near the dead plate, the said aperture
leading to the interior of the bar, and supplying air to the bridge. I also form
some bars open at the back end and closed at the front end, there being simply
apertures at the bottom, as at d, Fig. 1, for the admission of air to the interiors
of the bars and the bridge. With those fire-bars in which the bottom
apertures are at or near the middle of the furnace, as in Fig. 10, Sheet 2, I
employ a dead plate h, forming part of a box or chamber, having its bottom and
sides closed, and its top formed as a grate, or perforated with holes, the current
of air for the furnace passing through the front apertures f, to the interiors of
the bars, and through their open ends to the interior of the box or chamber,
and from thence through the grate or perforations ; in the dead plate to the
interior of the furnace, there being a door or slide k, for enabling the box to
be cleaned. When the apertures of the bars are at the front end for supplying
air to the interiors of the bars and the hollow bridge, but not to the furnace, the
box or chamber of the dead plate must be open to the atmosphere, and there-
fore in this case the box is open at the front, so that air can pass through the
fire-bars to the hollow bridge, and also through the grate or perforations in the
dead plate to the interior of the furnace, the back part of the bottom of the
box being used for supporting the bars; and for checking the draught and
giving air to the front part of the furnace, I employ, when required, a sliding
plate or fender in the ash-pit. The hollow bridge i, Figs. 1, 10, and 14 is
formed of two vertical plates, having at the top a grate 1, and at the bottom
perforated pipes m, Figs. 1 and 10. In the front plate there is an opening n,
leading to the interior of the bridge, and above and below this opening there
are plates o, p, extending across the furnace, the lower plate supporting the
fire-bars at that end, and the upper plate supporting fire-bricks q for
preventing the metal from burning. The air from the interiors of the fire-bars
rushes into the hollow bridge and passes through the grate l, and perforated
pipes m, and thereby consumes the smoke and gives additional heat, and when
required, I attach a pipe 7, Fig. 14, from the ash-pit to the bottom of the
hollow bridge i, and place in the pipe another pipe s, which pipes enable the
bottom of the bridge to be cleaned and also supplied with air. For splitting

page_text: the gases arising from combustion, and consuming them for the production of
heat and prevention of smoke, I place behind the bridge one or more cylinders,
each closed at the front, or at the front and back, by a circular or polygon-
shaped cone, either entirely closed and separate from the bridge, or perforated
with holes, and connected by a pipe to the bridge. Or instead of the cylinders
and cones I employ globes or cones, either solid or hollow, connected to the
flue or to a pipe leading to the bridge or to a pipe connected to the pipe in the
back flue. Or I suspend the vessels from the top of the flue or to pipes
passing through the water above the flue. Some arrangements of these vessels
for splitting the gases are shewn at t, u, v, Fig. 1; at w, x, Fig. 10; y,
Figs. 14 and 17; z, a', b¹, Fig. 21; and c¹, d¹, e¹, Fig. 22.
The foregoing arrangements are applicable to furnaces in the internal flues
of the boiler, as shewn in Sheets 1 and 2, but with slight modifications they
are applied to the outside of the bottom of the boiler, as in Sheet 3, and the
improvements in the fire-bars are also applied to the boilers of locomotive and
marine engines.
i
In Figs. 23, 24, 25, and 26, Sheet 5, I shew one arrangement of my
improved hollow fire bars for locomotive boilers; Fig. 23 being a plan of part
of the bar detached; Fig. 24 a longitudinal section of the same; Fig. 25 a
similar bar placed in the fire-box; and Fig. 26 a plan of the fire box with a
number of bars in it. The bearers for the bars are marked f, each having a
number of ribs g' for keeping the bars at their proper distance apart. Each
bar consists of a horizontal part h¹ and vertical part k¹, both cast together or
separate, but having through them holes 1', m³, the tops of the holes m' being
closed by covers n¹ where required.
In one arrangement of my improved boilers I form three internal flues, and
place the furnace at the outside of the bottom of the boiler, as shewn in Figs.
14, 15, 16, and 17. The smoke and gases pass from the furnace p¹ to the
take up q', then through the flue r¹ to near the front, and afterwards through
short pipes to other two flues to the chimney; or the smoke and gases pass
from the flue to the smoke box s¹, Fig. 14, and from thence through the
flues t, u, Figs. 15, 16, and 17, and also when desired through the hollow
stay to the back flue w', and from thence to the chimney; and instead of
setting the boiler on brackets of bricks resting on the brickwork foundation,
I set it on iron standards a³, Figs. 3, 11, and 17, resting on the foundation,
the said standards being bolted or rivetted to the boiler, and having projections
on which plates 6 can be placed to form external flues when required.
In other arrangements I fix to the shell of the boiler large tubes or
chambers, open at one end to the fire of the furnace, or to the heat from an

page_text: external flue, and closed at the other end and sides to the water in the boiler,
for the purpose of reducing the bulk of water, and greatly increasing the
heating furnace. These tubes or chambers are placed either between the
longitudinal internal flues of the boiler, as shewn at c³, Fig. 3, Sheet 1, or at
the sides of the flues, or used when there are no internal flues, and in some
cases they extend through the boiler, as shewn at d, Figs. 18 and 19, Sheet 4,
in a vertical, horizontal, or diagonal direction, and are open at both ends for
the circulation of heat. In any of the aforesaid boilers the furnaces may be
placed either in internal flues or at the bottom outside the boiler. And, for
improving the draught or checking the heat of the furnace, I send a jet of
steam into the flue between the damper and the furnace. For supplying heated
air to the furnaces; I place in the back flue leading to the chimney a pipe e³,
Figs, 1 and 10, Sheets 1 and 2, open at one or both ends, and connect to it
a pipe and pipe g³, Figs. 1, 3, and 10, having a number of pipes h³, opening
into the furnaces and flues. These pipes g³ pass from either the inside, as
shewn in Figs. 1 and 3, or along the top of the boiler, as shewn in Fig. 10;
or two inside pipes g³ may be employed, having vertical pipes h³ com-
municating with the flues, as shewn in Figs. 18, 19, and 20, so that the air
entering the first pipe shall become heated in the flue in its passage, and after-
wards delivered to the fire, or passed into the take up of the boiler; or I
employ a single or double acting air pump for forcing air through the said
pipes in order that it may be heated in its passage to the furnace or take up,
the object in both cases being to return a great portion of the heat which
would otherwise pass up the chimney; and; in some cases, I apply these air
pumps to the exhaust pipe of the steam engine, or to the top end of the con-
denser, in order to draw off heat and vapour, and pump them into the boiler,
or into the furnace or take up. At the top of the side flues of the boiler I
form small longitudinal flues leading to the back flue for the purpose of
drawing the heated air upwards, and encircling the sides of the boiler. These
small flues are shewn at k³, Figs. 3 and 17, and they may be open at the
bottom either their entire length, or having lengths of about two feet of
opening, and one foot of brickwork alternately.
My improved mode of manufacturing the boilers consists in using plates of
sufficient length to form nearly the circumference of the boiler, and instead of
overlapping the edges I bring them together as jump joints in contact with
ribs or longitudinal plates, and rivet them all together by two or more rows
of rivets. I also bring the transverse edges of the plates as jump joints in
contact with ribs forming part of welded hoops, and hold them all together

page_text: At
by rivetting the said hoops to the exterior or interior of the plates, as shewn
full size in Fig. 9, and at a reduced scale in Figs. 1, 2, and 18, in which latter
Figures the internal flues are shewn constructed in the same manner.
the top of the back flue of one boiler, or across the back flues of a number of
boilers, I place a cistern P, Fig, 1, for containing water, which will be heated
by the heat of the flue or flues, and from this cistern I take the water for
feeding the boiler or boilers, and thereby economize fuel. At the bottom
of the boiler I place one or more cylinders for catching the mud and
sediment, and also assisting in supporting the boiler. These cylinders are
shewn at m³, Figs. 10, 11, 12, and 13, Sheet 2, and Figs. 14 and 17, Sheet 3,
there being openings n leading to the mud cylinders and pipes o² at the side
of the cylinders for taking off the mud. In Figs. 12 and 13, Sheet 2, I shew
an improved arrangement of boiler for obtaining great heating power and other
advantages. This boiler consists of two shells p, q, connected together by pipes
, enclosed in a chamber of brickwork. The two shells and pipes con-
tain the water and steam, and in the shell p2 there are large flues s³ containing
the furnaces; and in the shell q there are a number of tubes 2 opening into
a take up, from which there is a flue passing underneath the boiler to the
front, and then splits at the sides to the chimney similar to the take up and
flues shewn in Figs. 10 and 11. This arrangement enables the chamber of
brickwork to act as a combustion chamber, and affords great facility for
cleaning the tubes.
"
For reducing steam from high to lower pressure I employ a box or
chamber u, shewn in the sectional plan and elevation, Figs. 27 and 28,
Sheet 6, the said box or chamber has a pipe or branch for the entry of the
steam from the boiler, and another pipe or branch w for its escape to the
engine or other machine where it is to be employed. At or about the middle
of the chamber there is a partition having two valves and seatings y, z,
one opening to the supply and the other to the discharge, and together acting
as an equilibrium valve. The spindles of the valves are connected to two
arms a³, 63, of a lever on the shaft c³, the arm 63 being also connected to the
rod of a small piston e³ working in a cylinder f at the top of the chamber,
and the valve in the chamber on that side is weighted according to the reduced
pressure required. When this valve box and valves are to be applied to
regulate the speed of the steam engine I connect the rod at the top of the
aforesaid small piston to a boss having a screwed hole to which is fitted a
screw at one end of a rod carrying at the other end a pulley placed between
flanges on the spindle of the steam engine governor. The aforesaid flanges

page_text: are so placed that, when the balls of the governor collapse, one of the flanges
will be in contact with the pulley, and give it motion so as to turn the screw
and increase the opening of the valves, but, when the balls expand, the flange
on the opposite side comes in contact with the pulley, and turns it in a reverse
direction, and lessens the opening of the valves, and as the valves are more open
and give more steam when the speed is becoming too slow, and less open when
the speed is becoming too great, it follows that the speed of the engine can be
regulated very efficiently. Or. I fix to the shaft c³, Figs. 27 and 28, which
carries the two arms a³, b³, two levers h³ in contact with tappets 3 fixed to
the shaft turned by the bevil wheels m³, connected by a shaft and gearing
with the shaft n³ shewn in the elevation, Fig. 29, the said shaft being worked
by the bevil wheel o³ on the governor spindle p³. The shaft 1³ passes through
the boss or collar q³ of the bevil wheel, and turns with it by means of a key
or feather, but is at the same time capable of moving to and fro. To the
governor spindle p³ I fix two flanges ³, s³, and place between them a pulley t³
fixed to the shaft u³, communicating either directly or by means of gearing
with the worm v³, Figs. 27 and 28, gearing into the worm wheel w³ fixed to
the screw ³, having a head y³ held to the shaft 1³, and its screwed part fitting
a nut 2. When the balls of the governor collapse, the flange will be in
contact with and turn the pulley t³, the worm v³, worm wheel w³, and screw x³,
and as the screw turns in its nut 23 it gives longitudinal motion to the shaft
and tappets k³, which as they revolve give greater up and down movement to
the valves y, z, thereby enlarging their openings for the greater supply of
steam, but when the balls expand the flange comes in contact with the
pulley; and turns the worm v3 and parts connected with it in a reverse
direction, so as to shift the tappets for enabling them to give less up and down
motion to the valves, and lessen the openings for the supply of steam, and
thus the speed of the engine is effectually regulated. It will be seen that the
tappets are fixed in opposite directions for the purpose of acting twice on
the valves for each revolution of the shaft 3, and it is obvious that the gearing
must be regulated accordingly. When the said box and valves are to be used
as a shut off or stop valve, the top of the piston rod is screwed as at a', Fig. 28,
and fitted to a nut in a handle or wheel b, so that when the wheel is
turned one way the valves can be pressed on their seatings, and shut off the
steam and opened when required by reversing the motion of the handle or
wheel.
Having now described the nature and particulars of my said Invention, and
the manner in which the same is to be performed, I desire it to be understood

page_text: that I claim, the improvements in furnaces and boilers, and parts connected
with them, for generating steam and heating fluids; and also for improved
apparatus for reducing and shutting off steam, and regulating the speed of
steam engines, as all such improvements are herein described and illustrated
in the accompanying six Sheets of Drawings.
In witness whereof, I, the said John Cass, have hereunto set my
hand and seal, this Eighth day of August, in the year of our Lord
One thousand eight hundred and sixty-five.
Signed, sealed, and delivered by the
within-named John Cass, in the
presence of
E. J. HUGHES,
Patent Agent,
Manchester.
JOHN CASS. (L.S.)