IMPROVEMENTS IN STEAM ENGINES AND BOILERS AND IN PROCESSES OR APPARATUS TO BE EMPLOYED IN WORKING THE SAME
Year: 1863

page_text: LETTERS PATENT to James Howden, of Glasgow, in the County of
Lanark, North Britain, Engineer, for the Invention of "IMPROVEMENTS
IN STEAM ENGINES AND BOILERS AND IN PROCESSES OR APPARATUS TO BE
EMPLOYED IN WORKING THE SAME."
Sealed the 14th June 1864, and dated the 19th December 1863.
PROVISIONAL SPECIFICATION left by the said James Howden at the
Office of the Commissioners of Patents, with his Petition, on the 19th
December 1868.
I, JAMES HOWDEN, of Glasgow, in the County of Lanark, North Britain,
Engineer, do hereby declare the nature of the said Invention of "IMPROVE-
MENTS IN STEAM ENGINES AND BOILERS AND IN PROCESSES OR APPARATUS
TO BE EMPLOYED IN WORKING THE SAME," to be as follows, that is to say :-
This Invention relates to several improved arrangements in the general con-
struction of steam engines and boilers intended chiefly for marine purposes, but
which can also be applied to engines used for other purposes whereby the num-
ber of working parts is diminished, the general operation of the mechanism
rendered more perfect, and greater economy and efficiency obtained.
One improvement according to this Invention consists in placing two pairs
of double expansive engines parallel to each other in such a manner that their
respective crank shafts also lie parallel, the two cranks on each shaft being
placed with their centres nearly in a straight line. The steam is worked from
the high to the low pressure cylinder in a manner similar to that for which

page_text: Letters Patent were granted to James Howden on or about the 4th day of
January 1862, and numbered 34. When two pair of these engines are
employed to drive a single screw, spur wheels are keyed on to the end of each
crank shaft to gear with a pinion on the end of the screw shaft, but when applied
to twin screws they are driven directly from the crank shaft of each engine,
in which case it is not absolutely necessary that these shafts lie parallel with
each other. By preference these engines are arranged so that the cranks of
one pair are nearly at right angles with the cranks of the other pair. These
engines may also be coupled when applied to twin screws by a side rod
or toothed gear for the purpose of equallizing the speed.
In the improved arrangement the condenser is placed between the pairs of
engines, thereby supporting the cylinders of each pair at their nearer sides,
whilst at the outer sides they are supported by columns rising from the sole
plate, the guide frames for the piston rods being partly attached to the con-
dlenser and partly to the outer frame or standard. It is preferred to employ
surface condensation in connection with these engines, which are arranged with
their tubes lying horizontally (though a common jet condenser may also be
used), doors being placed at back and front of engines to give access to the
tubes.
The whole of the pumps under this modification are placed at the front of
the engines on the lower part of the framing, and are actuated from a pin in
an overhung crank or disc from each crank shaft. Each pin works in a sliding
block, which block also works between the bars of a slide frame, on one side
of which are attached the rams for working the feed and bilge pumps whilst
to the other side of the same frame are attached the air and circulating pump
rods; by this combination the whole of the pumps are worked together horizon-
tally, their rams and rods thereby forming a compact and parallel guide bar
arrangement. The feed and bilge pumps are attached to the outer ends of the
framing, whilst the air and circulating pumps with their valve boxes are situated
at the central part of the framing, each pair of engines having the same
arrangement of pumps. The air and circulating pumps (which are preferred to
be double-acting) are placed back to back, whilst between them is placed
the chambers holding their valves, the one containing the air pump valves
being in connection with the condenser and hot well, whilst that containing
the valves of the circulating pumps are in connection with the sea and
surface condensers.
Another improvement under this modification consists in a simplified con-
struction of starting gear, which is accomplished by a rod passing through tho
condenser and across to each engine, and then connected to the link motion

page_text: by means of a pin working in a slot formed in the quadrant, the necessary
motion being imparted to this rod by an ordinary starting wheel and screw.
A second modification of this Invention consists in placing each pair of
engines at an angle with the horizon in such a manner that the connecting
rods are attached to the same crank shaft, the condensers being arranged
underneath the cylinders, the air and circulating pump, as well as the feed and
bilge pumps, being worked from one overhung crank pin and fixed to the
outer side of the framing, the air and circulating pumps of each pair of
engines working in a system of a guide bar arrangement, as in the former
modification, whilst the feed and bilge pumps may be placed in a vertical or
inclined position. Another improvement consists in working the afore-
mentioned combined system and arrangement of pumps in connection with
the several classes of marine engines as at present constructed, and actuating
the same from a pin in an overhung crank or disc. When this improved
construction of pumps is applied to engines having only common jet con-
densers, in which case the circulating pump is dispensed with, a similar guide
bar arrangement is carried out by applying a double rod to each air pump.
Included in this Invention are also certain modifications of those classes of
engines commonly known as the side and "grasshopper lever" engine, by
which their number of working parts is reduced and the whole action much
simplified, the former or side lever engines having their fulcra at or near
the middle of the levers, with the connecting rod at the furthest end from
the cylinders, whilst the latter or "grasshopper" engines have their fulcra
at the end of the levers furthest from the cylinders and the connecting
rods working in as close proximity to the cylinders as possible. The im-
provements according to this Invention in the above-mentioned classes of
engines consist in inverting the cylinders and placing their piston rods in
direct communication with single central working beams, to which they may
be connected by short links or by pins and bushes sliding in slots in the
end of the beams or levers to allow of the radial action of the latter. These
beams being formed, by preference, of two malleable iron plates and placed
directly under the crank pins, allow of simple straight connecting rods being.
used having single pairs of bushes at each end. In these improved engines.
the crank shafts are carried on a framing somewhat similar to the usual
arrangement. In these improved arrangements the condenser is situated'
between the cylinders, thereby forming their support at their nearer sides,
whilst at the outer sides they are supported by columns rising from the sole
plate, the guides for the piston rod being attached to their columns on one
side and on the other to the condenser. When surface condensers are used

page_text: in connection with them, the air and circulating pumps are actuated from a
cross bar, one pump being placed on either side of the beam, whilst the feed
and bilge pumps are worked from pins in the beam and connected therewith
in the usual manner; but when a common jet condenser is used it is preferred
to connect the feed and bilge pumps together to one end of the afore-mentioned
cross heads in lieu of the circulating pump.
Another improvement comprehended under this Invention consists in so
treating the feed water discharged by the air pumps from surface condensers
that its present injurious mechanical and chemical action on the boilers is
obviated. The manner in which this is carried out is by discharging the
water from the condenser into the hot well, which contains one or more
filtering beds, by preference composed of animal charcoal, which allows the
water to permeate freely into chambers in connection with the feed pumps,
the use of these beds being to retain and destroy all greasy and dirty matter
containing deposit, thereby enabling the feed pumps to deliver water into the
boiler in a state free from impurities.
Another part of this Invention contains several improvements of that system
of working "cut-off" valves, included under the afore-mentioned Letters
Patent granted to James Howden, on or about the 4th day of January 1862,
No. 34, and consists, firstly, in placing upon the back of the main slide valve
two bars, one at each side, so as to press slightly on the outer ends of the
cut-off plates and hold them in position at the back of the main slide valve, the
pressure of these bars being adjusted by means of springs. Secondly, instead
of using rods with projections to work the cut-off plates on or off the steam
ports as described, in my projecting pieces are cast or fixed on to the door of
the valve casing in a position so as to move the plates off the ports, leaving
them free for the entrance of the steam. The central projections for detaining
the plates and thereby causing the cut-off action are adjusted so as to cut off
sooner or latter, as may be required, by means of a double-action cam move-
ment, which causes the projections to approach or recede from each other,
which cam is actuated by a spindle fixed into it and passing through the back
of the casing to which a handwheel or lever is attached with an index and
pointer in connection with it for the means of adjusting the cut-off to any
portion of the stroke. In cases where cylinders are placed back to back, a
slight modification of this arrangement is placed transversely in the casing.
An additional motion may also be imparted to these cut-off plates for the
purpose of securing a quicker cut-off when such is desirable, which motion
may either be produced by the action of the valve on the cam, or by a similar
action obtained from any other working part of the engine, and the action of

page_text: a governor can also be applied to obtain a sooner or later cut-off, and thus
regulate the speed of the engine.
The last part of this Invention includes an improved construction of that
class of steam boilers described in my afore-mentioned Specification, and
consists in placing a separate series of tubes directly over the fire, access to
which is obtained by doors separate from those by which access is obtained to
the upper series, both series of tubes being contained in the same water
chamber.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Howden in the Great Seal Patent Office on the 18th
June 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
HOWDEN, of Glasgow, in the County of Lanark, North Britain, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria; by Her Letters
Patent, bearing date the Nineteenth day of December, in the year of our
Lord One thousand eight hundred and sixty-three, in the twenty-seventh year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said James Howden, Her special license that I, the said James Howden,
my executors, administrators, and assigns, or such others as I, the said
James Howden, my executors, administrators, or assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN STEAM ENGINES AND BOILERS AND IN PROCESSES OR APPARATUS TO BE
EMPLOYED IN WORKING THE SAME," upon the condition (amongst others) that
I, the said James Howden, my executors or administrators, by an instrument
in writing under my hand and seal, or under the hand and seal of one of them,
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 James Howden, do hereby declare the
nature of my said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement,

page_text: reference being had to the accompanying Drawing and to the letters and figures
marked thereon, that is to say :-
My said Invention relates to several improved arrangements in the general
construction of steam engines and boilers intended chiefly for marine purposes,
but which can also be applied to engines used for other purposes, whereby the
number of working parts is diminished and the general operation of the mecha-
nism rendered more perfect, and greater economy and efficiency is obtained.
One improvement according to this Invention consists in placing two pairs
of double expansive engines parallel to each other in such a manner that their
respective crank shafts also lie parallel, the two cranks on each shaft being
placed with their centres nearly in a straight line. The steam is worked from
the high to the low pressure cylinder in a manner similar to that for which
"Letters Patent" were granted to me, bearing date on or about the 4th day
of January 1862, and numbered 34. When two pair of these engines are
employed to drive a single screw, spur wheels are keyed on to the end of each
crank shaft to gear with a pinion on the end of the screw shaft; but when
applied to twin screws they are driven directly from the crank shaft of each
engine, in which case it is not absolutely necessary that these shafts lie
parallel with each other. By preference these engines are arranged so that the
cranks of one are nearly at right angles with the cranks of the other. These
engines may also be coupled when applied to twin screws by a side rod or
toothed gear for the purpose of equalizing the speed. In this improved
arrangement the condenser is placed between the pairs of engines, thereby
supporting the cylinders of each pair at their nearer sides, whilst at the outer
sides they are supported by columns rising from the sole plate, the guide
frames for the piston rods being partly attached to the condenser and partly
to the outer frame or standards. It is preferred to employ surface condensa
tion in connection with these engines, which are arranged with their tubes
lying horizontally (though a common jet condenser may also be used), doors
being placed at back and front of engines to give access to the tubes. The
whole of the pumps under this modification are placed at the front of the
engines on the lower part of the framing, and are actuated from a pin in an
overhung crank or disc from each crank shaft. Each pin works in a sliding
block, which block also works between the bars of a slide frame on one side
of which are attached the rams for working the feed and bilge pumps, whilst
to the other side of the same frame are attached the air and circulating pump
rods; by this combination the whole of the pumps are worked together hori-
zontally, their rams and rods thereby forming a compact and parallel guide bar
arrangement. The feed and bilge pumps are attached to the outer ends of the

page_text: framing, whilst the air and circulating pumps with their valve boxes are
situated at the central part of the framing, each pair of engines having the
same arrangement of pumps, also air and circulating pumps, which are pre-
ferred to be double-acting and placed back to back, whilst between them is
placed the chambers holding their valves, the one containing the air pump
valves being in connection with the condenser and hot well, whilst that
containing the valves of the circulating pumps are in connection with the sea
and surface condensers.
Another improvement under this modification consists in a simplified con-
struction of starting gear which is accomplished by a rod passing through the
condenser and across to each engine and then connected to the link motion
by means of a pin working in a slot formed in the quadrant, the necessary
motion being imparted to this rod by an ordinary starting wheel and screw.
A second modification of this Invention consists in placing each pair of
engines at an angle with the horizon in such a manner that the connecting
rods are attached to the same crank shaft, the condensers being arranged
underneath the cylinders, the air and circulating pumps, as well as the feed
and bilge pumps, being worked from an overhung crank pin and fixed to the
outer side of the framing, the air and circulating pumps of each pair of
engines working in a system of guide bar arrangement as in the former
modification, whilst the feed and bilge pumps may be placed in a vertical or
inclined position.
Another improvement consists in working the afore-mentioned combined
system and arrangement of pumps in connection with the several classes of
marine engines as at present constructed and actuating the same from a pin
in an overbung crank or disc. When this improved construction of pumps
is applied to engines having only jet condensers, in which case the circulating
pumps is dispensed with, a similar guide bar arrangement is carried out by
applying a double piston rod to each air pump.
Included in this Invention are also certain modifications of those classes of
engines commonly known as the "side" and "grasshopper" lever engines by
which their number of working parts is reduced and the whole action much
simplified, the former or side lever engines having their fulera at or near
the middle of the levers with the connecting rod at the furthest end from the
cylinders, whilst the latter or grasshopper engines have their fulcra at those
ends of the levers furthest from the cylinders and the connecting rods working
in as close proximity to the cylinders as possible.
The improvements according to this Invention in the afore-mentioned
classes of engines, consists in inverting the cylinders and placing their piston.

page_text: rods in direct communication with single central working beams, to which
they may be connected by short links, or by pins and bushes sliding in slots in
the ends of the beams or levers to allow of the radial action of the latter,
These beams being formed by preference of two malleable iron plates, and
placed directly under the crank pins, allow of simple straight connecting rods
being used, having single pairs of bushes at each end. In these improved
engines the crank shafts are carried on framing somewhat similar to the usual
arrangement. In these improved arrangements the condenser is situated
between the cylinders, thereby forming their support at their nearer sides;
whilst at the outer sides they are supported by columns rising from the sole
plate, the guides for the piston rod being attached to these columns on one
side, and on the other to the condenser. When surface condensers are used
in connection with these, the air and circulating pumps are actuated from a
cross bar, one pump being placed on either side of the beam; whilst the feed
and bilge pumps are worked from pins in the beam, and connected there-
with in the usual manner; but when a common jet condenser is used it is
preferred to connect the feed and bilge pumps together to one end of the
afore-mentioned cross bars in lieu of the circulating pump.
Another improvement comprehended under this Invention consists in so
treating the feed water discharged by the air pumps from surface condensers
that its present injurious mechanical and chemical action on the boilers is
obviated. The manner in which this is carried out is by discharging the
water from the condenser into the hot well which contains one or more
filtering beds, by preference composed of animal charcoal, which allows the
water to permeate freely into chambers in connection with the feed pumps;
the use of these beds being to retain and destroy all greasy and dirty matter
containing deposit, thereby enabling the feed pumps to deliver water into the
boiler in a state free from impurities,
Another part of this Invention contains several improvements of that
system of working "cut-off" valves included under the afore-mentioned
Letters Patent, granted to me on or about the 4th day of January 1862,
Number 84, and consists, firstly, in placing upon the back of the main slide
valve two bars, one at each side, so as to press slightly on the ends of the
"cut-off" plates, and hold them in position on the back of the main slide
valve, the pressure of these bars being adjusted by means of springs.
Secondly, instead of using rods with projections to work the "cut-off" plates
on or off the steam ports, as described in my former Specification, projecting
pieces are cast or fixed on to the door of the valve casing, in a position so as
to move the plates off the ports, leaving them free for the entrance of the

page_text: steam. The central projections for detaining the plates, and thereby causing
the "cut-off." action, are adjusted so as to "cut off" sooner or later as may
be required, by means of a double-acting cam movement, which causes the
projections to approach or recede from each other, which cam is actuated by
a spindle fixed into it and passing through the back of the casing, to which a
hand wheel or lever is attached with an index and pointer in connection
with it for the means of adjusting the "cut-off" to any portion of the stroke.
In cases where cylinders are placed back to back, a slight modification of
this arrangement is placed transversely in the casing. An additional motion
may also be imparted to these "cut-off" plates for the purpose of securing a
quicker "cut-off" when such is desirable, which motion may either be pro-
duced by the action of the valve on the cam, or by a similar action obtained
from any other working part of the engine, and the action of a governor can
also be applied to obtain a sooner or later "cut-off," and thus regulate the
speed of the engine.
The last part of this Invention includes an improved construction of that
class of steam boiler described in my afore-mentioned Specification, and consists
in placing a separate series of tubes directly over the fire, access to which is
obtained by doors separate from those by which access is obtained to the
upper series, both series of tubes being contained in the same water chambers.
And in order that my said Invention may be properly understood I shall
now proceed to describe the several Figures on the two Sheets of explanatory
Drawings which I have hereunto appended for the purpose of shewing
certain modifications under which my improvements may be judiciously
carried out in practice; the same reference letters marking the same parts
in the different views in which those parts are shown, that is to say :-
Figure 1, Sheet 1, of the accompanying Drawings is an elevation, and
Figure 2a plan of the arrangement of two pairs of double-expansive engines
for driving a single screw.
A is the high-pressure, and B the low-pressure cylinder of the one pair, and
A', B', the high and low pressure cylinders of the other pair; C is the spur
wheel on the end of the crank shaft of one pair of engines, and C³ is the spur
wheel of the other pair, gearing into the pinion D on the end of the propeller
shaft E in about the proportion of 2 to 1. In the right-hand pair of engines
the crank of the high-pressure cylinder is shewn on its top centre, whilst the
crank of the low-pressure cylinder is shewn in dotted lines approaching the
bottom centre. The pair of engines on the left-hand side have their cranks
nearly at right angles to the left-hand pair. The cylinders A and B of the
left-hand pair of engines with the passage from the valve to the high-pressure

page_text: cylinder are shewn in. section in Figure 2. The surface condenser F, fixed on
the engine bottom, supports the nearer sides of the four cylinders, whilst their
outer sides are supported by columns G, H, and G¹, H', the guide frames
being placed both on condenser and columns. The arrangement of pumps is
shewn in the front part of the engines, I being the air pump and J the cir-
culating or condenser cold-water pump; K, the feed, and L, the bilge pumps,
of the one pair shewn in section; and I, J, K, L, being respectively the
corresponding pumps of the other pair shewn in elevation, the whole being
fixed to the front end of the engine framing. The pistons of the air and
circulating pumps, and the rams of the feed and bilge pumps, are actuated by
the cranks M and M' on the ends of the engine shaft, as previously described.
The valves of the air and circulating pumps I and J are shewn in the half
section of their respective valve chambers, the valves of the pumps I', J',
being exactly similar. The valves of the air pump, which, with those of the
circulating pump, are preferred to be of india-rubber, are all attached to a
single brass casting fitted into planed grooves in the chamber, and dividing of
itself the chamber into the four separate parts required by the valves of the two
double-acting pumps, and jointed tight on the inside end against a facing on
the engine framing, and at the outside end by the chamber door. The part
0 of the chamber containing the suction valves is again divided into two
separate parts, the inside division containing the valve for the nearer end of
the air pump and the grating or openings for its discharge valve, and the
outsido division contains the valve for the further end of the air pump and
also the openings to its discharge valve. The suction part of the chamber is
connected by a port P with the condenser, and the discharge part is connected
by a port with the hot well in the engine bottom casting under the con-
denser. The suction and discharge ports P and Q are common to both air
pumps. The valves of the circulating pumps are contained in a similar
chamber immediately above the air-pump chamber, and they are placed:
precisely as those for the air pumps. The suction port R is in connection
with the sea through a passage cast in engine framing and a pipe joining a
sea cock to the framing. The water is discharged by the pumps up through
a branch pipe of the condenser fixed to upper side of the chamber, and passing
first back through the under division of tubes, returns through the middle
division, and finally is discharged through the ship's side by the pipe S after
passing through the upper division. The water may also be made to pass
through the whole of the tubes at once to the discharge pipe without returning.
In the feed and bilge pumps K and L the suction of the feed pump is in
connection with the hot well by a port a on the engine framing; b is the

page_text: discharge pipe; c is the suction of the bilge pump; and d is its discharge
pipe, the pumps K' and L' being exactly similar. The starting gear is worked
by the hand wheel T, the rod e from the screw box f passing through the
condenser, the valve links being attached at 9 and g³.
A modification of these engines, when each pair is attached to one crank
shaft, is shewn at Figure 8, both pairs of air and circulating pumps being
worked by a guide bar arrangement, as previously described, the feed and
bilge pumps being worked underneath by a connecting rod from the same
crank pin. This improved arrangement of pumps is also shown in Figures 4
and 5 of the accompanying Drawings as applied to a single pair of inverted
cylinder marine engines having a surface condenser. The air pump is 'in
connection with the condenser and hot well by ports in the engine bottom
casting, as described in connection with Figures 1 and 2. The inlet to the
circulating pump is at h, and the discharge to surface condenser at i. An
additional set of feed and bilge pumps j, k, is shewn worked from the same
crank pin by a connecting rod and cross bar.
An arrangement suitable for a pair of engines having a common jet con-
denser is shewn in Figures 6 and 7, being respectively an elevation and plan.
The air pump has two rods attached to its piston and draws the water from
the condenser as the others already described and discharges through ship's
side by the pipe l.
In Figures 1 and 2, Sheet 2, of the accompanying Drawings, is shewn a
modification of the improvements in "grass-hopper" and side lever engines
according to this Invention. Figures 1 and 2 are respectively an elevation
and plan of a pair of engines with grass-hopper levers. T, T", are the
inverted cylinders, resting on their inner sides on the surface condenser U,
their outer sides being supported by columns rising from the engine bottom
casting. The pistons are in direct connection by their rods and links with the
central levers or working beams V'and V', placed underneath, the connecting
rods W and W', composed of single bars, also rise directly to the cranks
above, forming a simple, strong, and compact means of transmitting the power
from the cylinders to the paddle shafts. The air pumps X, X', and circulating
pumps Y, Y, of each engine are worked from a cross bar m or m', joined by
a short connecting rod to a pin in the main levers.. The feed pumps n and n²;
and the bilge pumps o and o' are also worked from the main levers by studs,
as shewn. The air pumps draw the water and vapour of condensation from
the under part of the engine bottom casting in connection with the condenser,
and discharge the same into the hot well Z, to which the feed pumps are
connected. The hot well has also strongly attached to it the brackets p, p,

page_text: carrying the plummer blocks, into which the fulcrum centres of the levers
work. The circulating pumps are connected with the sea by the branches q, g³,
and discharge through passages cast in the bottom framing into the condenser
by the branch r. The description and Drawings of this modification where
the fulcra is at the end of the levers furthest from the cylinders renders it
unnecessary to shew plans of the arrangement of those engines having the
fulcra in the centre of their levers or working beams. In this latter arrange-
ment the crank shafts are carried in framing supported on columns rising
from engine sole plate, as is usual in side lever engines, the framing being
also strongly bound by stays of forged or cast iron to the cylinders which rest
on the condenser and outer columns, as in the previous arrangement. The
lever centres work in plummer blocks fixed on either side on the sole plate,
and the air and circulating pumps (when a surface condenser is used) are
worked in the same manner as shewn on the side of the centre nearest to the
connecting rod, but they may also be worked when a common jet condenser is
used on the end of the levers nearest to the cylinder, the feed and bilge
pumps being attached to one end of the cross bar in place of the circulating
pump.
The improvements in treating the water discharged by the air pumps from
surface condensers, so as to prevent the injurious action on, the boilers, is shown
in connection with Figures 1 and 2, Sheet 2 of the Drawings. The water in
being discharged by the air pumps into the hot well Z falls upon several
layers 8, 8, s, of animal charcoal carried on wire cloth attached to a frame of
wood or other material. The water after falling downwards through the
charcoal filters passes along and rises upwards through another similar filter t,
and afterwards falls on each side of the division containing this filter into the
spaces u of the hot well, from which the feed pumps take the water thus
purified from grease and other injurious matter.
A modification of the improvements in "cut-off" valves according to this
Invention is shewn in Figures 8, 9, and 10, Sheet 1 of the Drawings. The
"cut-off" plates v, v, are kept on the back of the main valve by the bars w, w,
pressed by the springs a, a, the "cut-off" plates being still moveable on the
back of the valve by a moderate pressure. The bars y, y, for giving the
"cut-off" are adjustable by the double-action cam z, a pin from the upper
bar working in one of the grooves, and a pin from the lower bar working in
the other groove. The "cut-off" action is given sooner or later, according as
the bars y, y, are moved from each other or towards each other, the action
being sooner the further out the bars are from each other. The main valve
carrying the plates v, v, after the "cut-off" has taken place bring them against

page_text: the projections 1, 1, on the back of the casing door before arriving at the
extremity of its motion in each direction, and allows the valve to clear the
steam port for the entrance of the steam on its return. The cam is worked
through a stuffing box on the back of the casing door by the spindle and hand
lever shewn, the different amounts of "cut-off" being registered by an index
and pointer. When the "cut-off" action is assisted by a motion from the
engine or regulated by the governor, a suitable lever is attached to the
spindle. A front view of the adjusting cam is shewn in Figure 11.
A modification of the improvements in steam boilers according to this
Invention, is shewn in Figure 3, Sheet 2 of the Drawings. The under series
of tubes 2 in this example consist of three rows, somewhat greater in this
example than those in the series above, fixed in the under side of the end
chamber 8, 3, access to them being given by the doors 4, 4, which are bolted
to the outside of the chamber in the manner shewn. As it is found in practice
that scale or deposit is formed much more quickly in the tubes directly over
the fire than in upper rows, access for cleaning is easily obtained by the
smaller doors 4, 4, without disturbing the joints or taking off the larger
doors above. The fire gases pass upwards through among the tubes to the
chimney above.
Having thus particularly described my said Invention, and the manner in
which the same is or may be used or carried into effect, I have to state that
I do not restrict myself to the precise details herein-before described or
delineated, and that I do not claim to have invented every separate detail
herein-before described and delineated; but that what I believe to be novel
and original, and claim as the Invention secured to me by the herein-before
in part recited Letters Patent, is,-
First, the arrangement of two pairs of double-expansive engines, so as to
work single or twin screws, the power being also applicable to other purposes,
as herein-before specified and described in connection with Figures 1 and 2,
Sheet 1 of the accompanying Drawings.
Second, the arrangement of double-expansive engines, as herein-before
specified and described in connection with Figure 3, Sheet 1 of the ac-
companying Drawings.
Third, the improved system of arranging and working the various pumps in
marine or other engines, as herein-before specified and described in connection
with Figures 1, 2, 3, 4, 5, 6, and 7, Sheet 1 of the accompanying Drawings.
Fourth, the improved arrangement of that class of engines known as "side
lever and "grass-hopper lever" engines, as herein-before specified and
"

page_text: described in connection with Figures 1 and 2, Sheet 2 of the accompanying
Drawings.
Fifth, the treatment of the feed water, as herein-before specified and
described in connection with Figures 1 and 2, Sheet 2 of the accompanying
Drawings.
Sixth, the improvements in "cut-off" valves, as herein-before specified and
described in connection with Figures 8, 9, 10, and 11, Sheet 1 of the
accompanying Drawings.
: Seventh, the improvements in steam boilers, as herein-before specified
and described in connection with Figure 3, Sheet 2 of the accompanying
Drawings.
In witness whereof, I, the said James Howden, have hereunto set my
hand and seal, this Seventeenth day of June, in the year of our Lord-
One thousand eight. hundred and sixty-four.
TAMES TOWDEN