CERTAIN IMPROVEMENTS IN STEAM ENGINES
Year: 1851

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
WHITELAW, of Johnstone, in the County of Renfrew, North Britain, Engineer,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Thirty-first day of July,
in the fifteenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said James Whitelaw, Her especial licence, full
power, sole privilege and authority, that I, the said James Whitelaw, my exors,
adors, and assigns, and such others as I, the said James Whitelaw, my
exors, adors, or assigns, should at any time agree with, and no others, from
time to time and at all times during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, my Invention of "CERTAIN
IMPROVEMENTS IN STEAM ENGINES;" in which said Letters Patent is contained
a proviso requiring that I, the said James Whitelaw, by an instrument in
writing under my hand and seal, shall particularly describe and ascertain the
nature of my said Invention, and in what manner the same is to be performed,
and shall cause the same to be enrolled in Her said Majesty's High Court of
Chancery within six calendar months next and immediately after the date of
the said in part recited Letters Patent.
NOW KNOW YE, that in compliance with the said proviso, I, the said
James Whitelaw, do hereby declare the nature of my Invention, and in

page_text: what manner the same is to be performed, to be particularly described and
ascertained in and by this present instrument in. writing as follows, reference
being had to the Drawings hereunto attached, and to the letters and figures
marked thereon, that is to say :-
My said Invention relates, first, to improved arrangements of steam engines
to be used for various purposes, and especially for actuating the screw propeller
in steam ships, or for driving other mechanism requiring a high rate of move-
ment, in which improved arrangements the principal advantages of a long
stroked engine are secured in combination with a short stroke of the piston,
the object being to embrace the chief points of excellence of both classes of
engine in one without at the same time involving the known disadvantages of
either kind. As applied to beam or side lever engines, this principle is in part
carried out by placing the main centre of the beam or side lever nearer to the
piston rod centre line than to the connecting rod centre. The same general
arrangements also embody various other contrivances or modifications for in-
creasing the efficiency of steam engines, and diminishing the space, occupied by
them, which contrivances or modifications I shall hereafter more fully describe.
Second, to a system or mode of securing superior uniformity of. speed to the
crank shaft of steam engines working expansively, by so proportioning. the
weight of certain of the moving parts that their inertia may tend to equalise
the action of the variable steam pressure in the cylinder.
Third, to the securing of increased nicety of adjustment of the rate of steam
engines by the application of a secondary action to the apparatus for regulating
the expansion or the throttle valve.
Fourth, to an arrangement for balancing the steam pressure on the backs of
slide valves by a counter pressure beneath the faces.
Fifth, to an improved arrangement of buckets or lifting pistous for air pumps,
and also for valves for various purposes.
3
S
Then as regards the first head of my improvements,-
Figure 1 on Sheet 1 of my Drawings represents a transverse section of the
screw steamer "City of Glasgow," shewing a side elevation of one of her
engines.complete. Figure 2 is a corresponding plan of the cylinders, foun-
dation plate, and gearing of both engines, shewing the space they occupy.
In those engines the main centre is placed midway in the length of the working
beam, the steam cylinders being on one side of the ship and the cranks on the
other, whilst the motion is communicated from the crank shaft to the screw
shaft by a spur wheel and pinion. The distinction between this kind of engine
and one form of my improved engine is to be explained in reference to
Figures 3 and 4 on the same Sheet of Drawings.

page_text: Figure 3 is a transverse section of a vessel similar' in all respects to that
represented in Figure 1, but shewing an elevation of my improved engine.
Figure 4 is a plan corresponding, shewing the actual horizontal space taken
up by a pair of such engines. In this arrangement the cylinder A is placed
on one side of the vessel; and the piston rod is connected by links to the end B
of the working beam: This beain, in place of being set to work upon a centre
cqui-distant from each end of the beam, as in Figure 1, is carried on the
centre C, placed considerably nearer to the centre line of the cylinder than to
the connecting rod centre. In this example the distance from B' to C, the
respective centres of the piston rod connection and the main centre of the
beam, is one half that compréhended between C and D, the main centre and
the connecting rod" centre. In this way the engine has a short stroke, and
therefore admits of being worked at such correspondingly high speed as may be
required to drive the" shaft of the screw propeller directly or without spur
wheels or other intermediate gearing,at the same time that" the reduced
pressure on 'the crank and its increased length give to this engine most of the
advantages of one of the ordinary kind, having a length of stroke even greater
than that corresponding to the length of crank in my improved engine. In
addition to these important points, the engine is cheaper in construction, lighter,
and occupies less room than the ordinary engine. In this kind of engine the
cylinders instead of being side by side may be set one on each side of the vessel;
so as to balance each other."
The diagram, Figure 5, illustrates an arrangement of this kind of engine
contrived to take up still less space accross the ship than that last described.
It is shewn adapted to driving a screw propeller. The three centres A, B, C,
are not placed in the same straight line; the centre C of the connecting
rod end is placed lower than the other two centres A and B, and hence
crank or screw propeller shaft D may be placed closer to the cylinder
with a given length of beam than when the three centres are in one line,
thus making a shorter engine.
the
+
Figure 6 is a transverse section of a ship similar to the sections shewn
in Figures 1 and 3, but fitted with a pair of engines constructed according
to another modification comprehended in my improvements. Figure 7.
is a plan of the base or foundation of the engines corresponding, shewing
the double crank shaft in position. Figure 8 is a plan of the upper portion
of the engines, in which the top of the framing, main centre bearings, main
centres, the working beams, and the air pump levers are shewn. Figure 9
s a plan of a portion of the crank shaft, shewing the manner of con-
ecting the lower ends of the connecting rods with the crank pins. This

page_text: form of engine is a modification of that illustrated by the diagram figured 5,
and takes up still less space. The steam cylinders A are placed one on cach
side of the vessel, and the cross bead of cach piston rod is connected by links
with the short ends B of its pair of working beams, which oscillate on the main
centre C. The opposite longer ends D of the two pairs of working beams are
jointed to four separate connecting rods, which pass downwards to the two
cranks on the screw shaft E, where each pair of rods is jointed to a separate
crank, one rod end on each side of the engine being single or plain, and the other
double or forked, as shewn in Figure 9. The side plates of the two beams G
are set a greater distance asunder than in the case of the other pair of
beams E, in order that the latter may work through or between the side plates
of the former, as clearly shewn in the plan, Figure 8. In this way each side
set of beams is made to work within a space not much greater than that
ordinarily occupied by a single beam, and the corresponding beams G, G,
and H, H, of each pair are fasts on the ends of the transverse main centres or
rocking shafts F, passing from side to side, and carrying levers I, which may
work the air pumps placed as shewn at J in Figure 7. This arrangement of
the engines affords great advantages in economising space, whilst the cylinders
and air pumps are made to balance exactly on each side of the kecl line. This
economy of space is in part effected by setting the air pumps to work obliquely,
as shewn in Figure 6.
Figure 10 is a diagram of a horizontal cylinder engine, arranged to work so
as to secure the advantages of the differential or unequally divided beam. The
cylinder A has its piston rod connected by a link at B, nearly at the middle of
the length of a lever or beam C, D, which works on a fixed centre at C. In
this way the end D of the beam, by having a traverse of about double that of
the piston, actuates the long crank E by means of the connecting rod F. The
other end of the beam may be made available for actuating a pump by an
extending arm or lever G, as shewn in my Drawing. On referring back to
Figure 3, it will be obvious to the practical man that if the slide valve were
placed either on one side or behind, instead of in front of the cylinder, as
therein represented, the cylinder might be placed much lower down, and this
would admit of the working beam being also lowered, provided a sufficiently
long connecting rod could still be obtained.
Figure 11, Sheet 2, of my Drawings, is a diagram of a vertical cylinder
engine, which admits of a sufficiently long connecting rod, even when the beam
is brought lower down towards the crank than in Figure 3 on Sheet 1. The
cylinder A has its piston rod B connected by the short link C to the short end D
of the working beam. The beam works on the main centre E, and its opposite

page_text: longer end is jointed at F by a link G to the upper end H of the connecting
rod I, which descends to the crank J beneath. The upper end of the link G,
with the joint centre of the upper end of the connecting rod, may be guided ver-
tically, either by a parallel guide or by a radius bar, as shewn by the horizontal
dotted line, the fixed centre of the radius bar being set at K. In this way a
long and effective connecting rod is obtained with a low position of the cylinder
and working beam.
Figure 12 on Sheet 2 of my Drawings is a diagram of a pair of vertical
cylinder engines, with working beams brought very close down towards the crank
shaft. The cylinders A are fitted up on the "trunk" principle; that is, with
hollow trunks or rods B attached to the upper sides of the pistons, and working
through stuffing boxes in the cylinder covers, like the ordinary piston rods.
The pistons are jointed, as shewn at C, to the lower ends of links D, which work
inside of the trunks B, and are jointed by their upper ends at E to the short
ends of the working beams, carried on main centres at F. The opposite long
ends of these beams are jointed at G to the lower ends of the links or short
lengths of connecting rods H, which are again connected by joints at I to the
upper ends of the main lengths J of the connecting rods. The latter, passing
downwards, are jointed at their lower ends to their respective crank pins K of
the main shaft L. In this instance, unlike the arrangement in Figure 11,
the short links H add in reality so much more effective length to the main
connecting rods J. In other terins, the effective length of the connecting rods
is equal to the whole length from G at the extremity of the long end of the
working beam to K at the crank pin. The upper ends of the links H are
therefore not guided in a vertical direction, as in Figure 11, but each beam
is made to act as a guide to the connecting rod of the other by means of the
rocking levers M fastened on the main centres. The upper ends of these levers
are jointed to links N, the opposite ends of which are similarly connected at [
to the joints in the connecting rods G, I, K. By this means, the action of each
beam guides the connecting rod of the opposite beam, retaining the centres I
at the proper effective angle for working; that is, the centres I are so guided
as to work nearly in the same curve, through which a point at this distance
from the upper end, measured along a straight inflexible rod of the length G, I, K,
would work, so as to give the jointed rod the full working advantage of a straight
inflexible rod of about the same length. The rods O, depending from the
working beams, may work air or cold water pumps. In either of the arrange-
ments shewn in Figures 11 and 12, the working beams may be brought as
close or closer to the cylinder cover by causing the cylinders to oscillate

page_text: slightly on trunnions in the usual way, the piston rods being jointed directly to
the beam ends.
....
1:
Figure 13 on Sheet 1 of .my. Drawings is a diagram of a Woolf's or double
cylinder expansive engine, arranged according to my improvements.. In this plan
A is the main centre of the working beam; on each side of which centre, and at
suitable distances asunder, are placed the small or high-pressure cylinder B and
larger or low-pressure cylinder C, their respective piston rods being connected to
the main beam at D and E. From the end F of the working beam the connecting
rod descends to the crank pin G below.. It is obvious that by this arrangement
the united effect of the pressure of the steam on the two short stroke pistons is
made to act upon a long crank, as in the plans which I have, herein-before
described. The action of the pressure. of the steam on each piston is also
balanced on each side the main centre. The steam ways communicating between
the cylinders are straighter than in the ordinary Woolf's engine, inasmuch as the.
steam from the upper end of the small cylinder passes directly into the corre-
sponding upper end of the large one; and similarly the exhaust at the opposite
ends is from the lower port of the small cylinder to the corresponding port of
the larger one, and one cylinder being placed near the other, the connecting
steam passages are shorter than they are in other engines of this class. Where
it is desirable to avoid the use of cylinders. of very large diameter, two short
cylinders of small diameter, and each fitted with a piston, may be erected one
upon the other, to work with one piston rod. The effect of a short stroke of
piston with a long crank may be secured by placing, the cylinder between the
main centre and the connecting rod end of the beam. This arrangement is
capable of easy illustration in Figure 13, where, by removing the small
cylinder B and the short end of the beam, the cylinder C will act upon the
main beam as upon a lever of the third order, giving the connecting rod F the
required amount of stroke, upon the same principle as that of Figure 10. It
will also be obvious that the arrangement shewn in Figure 18 may be modified
by transposing the relative positions of the large and small cylinders, the small
cylinder being placed on the connecting rod side of the main centre.
The second general head of my improvements has reference to an arrangement
for securing superior uniformity of motion to the crank shaft of engines working
to a high degree of expansion by so proportioning certain of the moving parts
of the engine that the weight or the inertia arising therefrom may assist in pro-
ducing greater uniformity in the power actually applied from the steam cylinder
to the crank pin by equalizing the variable pressure due to the gradual expan-
sion of the steam in the cylinder. In other terms, I propose to proportion the

page_text: weight of certain of the moving parts to the initial pressure of the steam and
the degree of expansion, so that the extra steam pressure at the early part of
the stroke shall be applied in producing an amount of momentum in those
moving parts, which momentum will be given out or expended in assisting the
exertions of the attenuated steam at a later period of the stroke. By this
means the effect of the varying steam pressures is made to give a more uniform
actuating pressure to the crank pin than in the ordinary expansive engine.
As an example of the effect of this system of working, I may refer to Figure 10
on Sheet 1 of my Drawings, representing a horizontal cylinder engine, where,
if the piston and other moveable parts through which the piston's motion is
conveyed to the crank pin were very light, the pressure on the crank pin would
vary nearly to the same extent as that of the steam in the cylinder. But if
the weight of the piston is increased to such an extent that it will take an
amount of pressure about equal to the excess of the initial over the mean
pressure in the cylinder to keep up the velocity of the piston, and the move-
able parts which transmit its motion to the crank pin to the extent required
during the time.the crank makes, say, one fourth of a revolution from either
of its dead points or from-its position at the time the piston is at either end of
the cylinder, and if in this position of the crank the steam has just reached its
mean pressure, it is evident that as the whole of the excess above the mean
pressure has been spent in imparting motion to the piston and the parts
conveying the motion of the latter to the crank pin, that pin, as well as the
crank shaft, must have been actuated during this time by an uniform or nearly
uniform force equal to that due to the mean steam pressure in the cylinder.
The principle of this system then is to cause the initial excess of steam pressure
over the mean pressure at the early portion of the stroke to communicate
to certain of the moving parts of the engine their full amount of momentum,
and afterwards, when this excess ceases or becomes negative, to cause the
momentum so given to assist in turning the crank to the extent which shall
maintain an uniform or nearly uniform pressure on the crank pin throughout
its entire revolution. Under such a system the strength of certain parts of
the engine may be diminished, whilst its motion is made nearly as uniform as
that of a non-expansive engine.
Although I have herein referred to the application of this system to
borizontal cylinder engines, the plan is obviously applicable to vertical cylinder
or other engines also. But in the case of vertical cylinders, as in Figure 3
on Sheet 1 of my Drawings, wherein the weight, pressure, or force applied to
the working beam should always be in equilibrium on each side the main
centre, it may be necessary or advisable, in cases where additional weight is

page_text: required to increase the inertia, to place part of the added weight on the
piston and part on the connecting rod, or on the connecting rod end of
the beam.
The third branch of my Invention relates to improved governors or speed regu-
lators for the attainment of superior nicety of adjustment of the rate of motion
of the engine. Figure 14, on Sheet 1 of my Drawings, is a complete side eleva-
tion of one form of governor, with its regulating mechanism attached; Figure 15
is a vertical section through a portion of the governor spindle, and part of slide
mechanism; Figure 16 is a horizontal section of the spindle, with a plan of
the lower sliding crosshead; Figure 17 is a plan of the extension cam; and
Figure 18 is a diagram representing the pair of adjusting star wheels with two
of their fixed detents. The cam A for working the expansion valve is carried
round by a spiral feather B on the lower end of the governor spindle, and had
a long boss C fitting loosely to the spindle, and passing upwards for connection
with the pendulum action above. Then as the pendulum balls expand with
the increased rate of the engine they draw the cam upwards, thus traversing
it along its spiral feather B, and setting it forward to cut off the steam earlier.
Similarly the pendulum action brings down the cam again as the balls contract
on the diminution of the engine's speed, and thus the cam is set back. In
this way the upward or downward traverse of the sliding tube D of the
governor causes the cam A to be set back or forward, as the case may be, on
its spindle, thus altering the extent of expansion. The lower end of the
tubular slide D, which fits loosely on the upright spindle, and is linked in the
usual way to the pendulous arms above, is formed with a crosshead E, having
an eye at each end bored out to receive the vertical spindles of the star wheels
F, which are carried round with the governor spindle. On the two fixed
brackets G, set on opposite sides of the governor spindle, are fixed two sets of
stationary pins or teeth II and I, each pair being in the same plane, and when
the engine is working at its proper rate the star wheels F revolve with the
spindle of the governor at such a height as to work clear of the fixed teeth
Hand I; but should the engine increase its speed the interior portions of the
peripheries of the star wheels F will come in contact with the inner and
higher pair of pins II. When this occurs the revolution of the star wheels
with the governor spindle will cause them to turn upon their own individual
axes and if the governor revolves, as indicated by the arrow in Figure 14, this
action will also cause the star wheels to turn in the direction indicated by the
arrows upon them. If, on the other hand, the engine's speed should decrease
with the governor spindle still going in the same direction, then the exterior
part of the periphery of the star wheels will similarly come in contact with the

page_text: outer pins I of the brackets G, as represented in the diagram, Figure 18, when
the star wheels will be turned in the opposite direction, as pointed out by
the arrows in that Figure. These two opposite actions of the star wheels are
made available for securing an additional power or secondary action of regu
lating the speed of the engine through its expansion valves by means of
the vertical spindles J, on the upper ends of which the star wheels are fast.
These spindles are screwed at their lower ends, and are passed through screwed
eyes in the crosshead K, attached to the upper end of the boss of the cam A.
This crosshead fits loosely in a ring groove in the cam boss, and carries a side
projecting piece L, which works into a short groove in the governor spindle,
and this serves as a vertical guide for the crosshead during its traverse up or
down, whilst the cam boss works round within its collar. Similarly the
vertical traverse of the tubular slide D of the governor is ensured by a cotter
er flat stud passed through the governor spindle projecting on each side
through a vertical slot in the slide. By the adoption of this arrangement, as
the expansion cam A has a partial turn communicated to it in either direction
by the upward or downward traverse of the governor slide D, the star wheels
F also get a partial revolution correspondingly as they come in contact with
one or other of the two pairs of fixed pins H, I, and thus what I term a
secondary action is given to the cam, setting it still farther forward or backward
by the revolution of the screwed spindles J through the eyes of the crosshead K.
And this additional or secondary action will go on until the gradual arrival of
the engine at its true rate of working shall bring the star wheels F between
and clear of the fixed teeth II, I. By this means if the engine is exposed to
varying degrees of resistance, this additional movement will give it a greater
nicety of adjustment and keep it at a more uniform rate than if it were
unfurnished with such secondary action. By a slight addition to the
mechanism provision is made for the prevention of the accidental turning of
the spindles of the wheels F too far in either direction. The wheels are
attached to their spindles by stiff friction, and the eyes of the crosshead K. are
furnished with inclined teeth or detents on each side corresponding to similar
teeth set in reverse directions on the lower and upper sides of the upper and
lower collars M, N, fast on the spindles. Thus when the spindles have turned
to the full extent allotted to them in either direction these catches will come
into action and prevent further movement, whilst the stiff friction connection
of the wheels on their spindles will allow the wheels themselves to turn or
move free when brought in contact with the fixed teeth H, I. By a slight
modification of this arrangement one of the star wheels may be dispensed with,
a spur pinion being placed on one of the spindles, as at O, to gear with the

page_text: loose pinion P on the governor spindle, which pinion again gears with the
third pinion Q, fast on the opposite star wheel spindle. In this way the revo-
lution of one. star wheel spindle is communicated to the other to give both a
simultaneous movement, whilst one star wheel only is used. Or- the three
pinions may still be used, even with two star wheels, in order to insure the
simultaneous movement of the two spindles in case one wheel should at any
time come into action before the other. Instead of having merely two pairs
of fixed pins H, I, three or more pairs may be used and set at different
heights in order that when the engine's rate is only slightly faster or slower
than it ought to be, the secondary action may come into play with greater
delicacy. The same effect may also be produced by two pairs of pins, as
shewn in Figure 14. In engines working at a high velocity, where it might
be injudicious to work the governor spindle at the rate necessary for the
ordinary single cam, as in Figure 17, the governor may be reduced in speed if
fitted with a cam made double or triple to correspond to this reduction in the
rate, or instead of having the cam upon the governor spindle itself, it may be
carried on a separate spindle working in connection with the engine, and if
adapted to that spindle in the same way as the cam A is connected to the
spindle in Figure 14, the cam may be moved backwards or forwards as required
by means of a lever or other connection with the governor, and the secondary
action may also in this case be applied, so that the cam, if placed on a separate
spindle, may be made to regulate the speed to as great a degree of nicety as if
it were placed on the governor spindle. And although I have herein described
this apparatus as applied to actuate a cam fitted on a spiral feather, it is
obvious that it may be adapted to work a tapering cam or other apparatus,
such as "Field's valve," where the cam is simply traversed along in the
direction of the axis of the spindle on which it is carried.
governor
Figure 19, on Sheet 1 of my Drawings, is a complete side elevation of another
modification of my improved secondary action governor; Figure 20 is a vertical
longitudinal section of a portion of the governor spindle in detail, as fitted with its
regulating mechanism; Figure 21 is a side view of one of the adjusting screw
rack pieces; and Figure 22 is a corresponding horizontal section or plan of
the same. In this arrangement the main spindle carries on expansion cam
A fitted to work on a spiral feather B, as in Figure 14. The boss of this cam
has a collar C on its upper end, covered by a ring cap by which it is connected
to the T ends of the screw racks D, set one on each side of the spindle. The
upper ends of these serew racks, which fit into vertical grooves in opposite
sides of the spindle, are made thicker than below, and are passed through the
lower end of the double pulley piece or pair of toothed wheels E, F. This

page_text: Beneath the lower
piece consists of a large and small plain, pulley or toothed wheel connected
together by an intermediate boss G, and the lower portion of its bore is screwed
with threads to suit the screw. rack threads of the pieces D. The upper
larger pulley E is recessed on its upper surface or end, and has a metal ring
screwed down upon it, embracing collar or T ends on the lower ends of short
pieces H, which fit in vertical grooves in opposite sides of the governor spindle.
The upper ends of these pieces are also T. shaped, to be similarly secured to
the lower end of the tubular slide I of the governor.
wheel F a spur wheel J is keyed on the governor spille in gear with a
similar, wheel K. keyed on the lower extremity of the short vertical spindle L
carried in fixed brackets. Immediately above the wheel K is another spur
wheel M, loose on the spindle L, and carrying a clutch piece on its
upper side,
this wheel being in gear with the lower wheel F on the governor spindle.
Near the upper end of the same spindle L is another loose wheel N, similar to
the wheel M, but having fewer teeth in. it, and gearing with the upper wheel
E on the governor spindle. Between the two wheels M and N is a double
sliding clutch O, connected by a transverse pin passed through a slot in the
spindle I, with the lower end of the vertical rod P, which passes down the
upper tubular portion of the spindle L from above. The upper end, of the
rod P is connected by a revolving joint to the extremity of a short horizontal
arm Q, the opposite. end of which is bolted to the flanges of a collar piece R
fitting loosely in the ring groove in the lower end of the sliding tubular piece
I of the governor. In this way the collar, R is stationary whilst the tubular
slide I revolves within it, and as the collar rises and falls with the pendulum
action, it, elevates or lowers the rod P by means of the arm Q, thus bringing
the double clutch O into gear with either of the wheels M, N. As the spindle
constantly revolves from the action of the pair of wheels J, K, when the
engine goes too slow the revolving clutch O, comes into gear with the lower
wheel M, as represented in Figure.19. This wheel being thus put in motion
actuates the spur wheel F on the governor spindle, so as to drive it at a rate
slightly faster than that of the governor spindle. This being the case, the
wheel F, in place of merely revolving with the screw rack pieces D, being now
carried faster than they are, traverses to the extent of such increase along the
threads of the screw racks. By this means a secondary action in a downward
direction is given to the expansion cam A, in addition to the direct downward
movement given to it by the descent of the tubular slide I, thus setting back
the cam upon its spiral feather. On the contrary, when the engine exceeds its
regular rate, the clutch O is brought into gear with the upper wheel N, which
has fewer teeth in it than the wheel E on the governor spindle with which it

page_text: gears. This difference in the number of teeth then tends partially to suspend
or reduce the rate of movement of the wheel E, so that as the screw racks
revolve within its boss this differential action causes it to traverse upwards,
and set the cam A forward upon its spiral feather, in addition to the movement
given to it by the governor slide I. Then, as the rate of the engine varies
either way, this action takes place accordingly untill the attainment of the
proper rate brings the clutch O between and free of either of the wheels M, N.
Figure 23, on Sheet I. of my Drawings, represents the plan which I adopt for
giving a secondary action to the ordinary throttle valves of steam engines.
The rod A is supposed to be connected to the ordinary governor action, and
its end is attached by a revolving joint to one end of the tubular piece B,
arranged to revolve when necessary in bearings in the brackets C, and having
a spur pinion D formed on its centre. At the opposite end of the tubular
piece B is attached the rod E leading to the throttle valve, this rod being
screwed into the end of the tubular piece. The same brackets C also afford
supports F for a short spindle, having upon it two loose spur pinions G. At
H is a constantly revolving spindle, carrying a small bevil pinion on its
extremity, in gear with the pair of bevil pinions, one of which is attached to
each of the loose pinions G. Then, as the pendulous action of the governor
traverses the rod A in either direction, if traversed far enough it brings the
pinion D into gear with one or other of the pinions G, which constantly revolve
in contrary directions; when this occurs the pinion D and tubular piece B are
driven round so as to screw back or forward the end of the rod E, and thus
give a secondary action to the throttle valve. This may obviously be made to
regulate the action of various kinds of valves, and especially that of the contri-
vance known as Rowan's fluctuating slider.
The fourth head of my. improvements comprehends an arrangement for
balancing the external steam pressure on the back of side valves of various
kinds. Figure 24, on Sheet I. of my Drawings, is a longitudinal section of a
single cup valve, valve chest, and steam ports of an engine to which the plan
is applied. Figure 25 is a transverse section of the same parts corresponding.
The slide valve A has a short and shallow groove B formed along a portion of
the two parallel face flanges, which run in the direction of the valve's travel.
These grooves correspond to similar grooves or recesses formed in the cylinder
face on which the slide works, such recesses having side or lateral openings in
connection with the tubes C, which communicate with a force pump or pumps,
or other apparatus or reservoir for keeping up an internal fluid pressure
within the recesses in the cylinder and valve faces. By this means the upward
pressure beneath the valve may be made to balance that of the downward

page_text: steam pressure, and thus ease the frictional working of the valve. Should the
upward pressure be at any time so great as to tend to elevate the valve from
its working face, provision may be made for keeping it down by wedge side
plates D, adjustable on the two angles of the side flanges.
Figure 26 exhibits a simple form of pump or pressure apparatus, which may
be employed for keeping up the balancing fluid pressure. A is a small cylinder
fitted with a piston, which is acted on from above by a link jointed to a
lever working on a fixed centre B, and weighted at its free end by the
weight C. This cylinder opens at its bottom end into a horizontal pipe, one
side D of which communicates with the fluid reservoir, and has a clack valve
opening towards the cylinder. The other end E, or continuation E of this pipe,
has a clack valve opening from the cylinder, and is made to communicate with
the tubes C, delineated in Figure 25. When in use the pressure of the
weighted piston on the fluid in the cylinder beneath it keeps up a constant
fluid pressure beneath the engine slide valve to the extent required. When,
however, from leakage or other cause, the piston descends any even the
slightest distance towards the bottom of its cylinder, the tappet F on the
continual working rod G will give the lever a lift, thus elevating the piston in
its cylinder, and causing the inlet valve of the pipe D to admit a further fluid
supply. This will be continually repeated as often as any escape takes place, the
traversing tappet giving occasional slight lifts to the piston for the restoration
of the fluid pressure. To insure constant action two pumps should be used, in
order that one may be always furnishing the necessary pressure.
The fifth and last branch of my improvements embodies an arrangement
for increasing the efficiency, durability, and case of action of air pump
and other buckets or lifting pistons and valves. Figure 27 is a vertical
section of a cylinder or air pump barrel fitted with my improved bucket,
also shown in section; Figure 28 is a horizontal or transverse section of
the pump barrel, shewing the bucket in plan within it; Figure 29 is a plan
of the bucket itself, detached and fitted to the pump; Figure 30 is a plan
of the second story or seat of the bucket valve detached; and Figure 31 is
a plan of the upper guard for the smaller annular valve or upper story. The
bucket, which is packed in the usual way, has first of all an exterior large
annular waterway through it, as at A, strengthened and connected to the
inner portion by radial web pieces. This waterway is covered over by a flexible
or elastic ring or annular valve B, forming the lower story or lift. This valve
is held or secured by its inner edge down on its seat by the binding pressure
of the second story piece C, which acts as a guard to keep the valve from
rising too high, whilst it has also a cylindrical collar or projection fitting into

page_text: the upper portion of the second story annular waterway D; similar to but
smaller than the lower one A. This collar has also an annular thoroughfare
in correspondence with the waterway beneath it, and this is covered by the
elastic annular valve F, which is held down by the upper guard G. This
upper guard is kept in position by a cutter passed transversely through the
bucket rod, and thus binds both valves and guards securely down. Such a
bucket will act much quicker than the ordinary kind, and with far less concussion,
whilst it affords a clear waterway and brings the rising fluid column nearer to
the centre of the pump than can be accomplished in the usual way.
N
"Having now' described and particularly ascertained the nature of my said
Invention, , and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that I do not confine' or 'restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as many variations may be inade 'therefrom without
deviating from the principles or main features of my-Invention. But what I
consider to be novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent, is,
१.
First, the systems or modes of constructing steam engines, and the general
arrangements connected therewith, as herein before described.
Second, the employment and use of steam engines fitted with cranks of a
length more than equal to one half the stroke of the piston, for the purpose of
enabling such engines to be driven at a higher rate of speed than can be
accomplished with ordinary engines of a similar length of crank."
Third, the combination of the respective advantages of both long and short
stroked' engines in one' engine.
Fourth, the system or mode herein-before described of arranging steam
engines to work at a high rate by causing a short-stroked piston to actuate
a long crank :
Fifth, the system or mode herein-before described of securing the advantages
of the effective leverage of a long crank with a short stroke of the piston.
Sixth, the employment and use of beam or side lever engines, in which the
three centres of the piston rod, connecting main centre, and connecting rod
centre, are not in one plane or at the same level, as a means of economising
space.
4
Seventh, the "system or mode of arranging or constructing steam engines
represented in Figures 6, 7, and 8, on Sheet I: of my Drawings.
Eighth, the employment and use of steam engines in which the two systems
of placing the three working centres out of the sanie plane, and what I have
termed my differential or unequally divided beams, are combined.

page_text: Ninth, the system. or mode of constructing steam engines with beams or
side levers working through or between each other, as delineated in Figures"
6 and 8 on Sheet I. of my Drawings.
Tenth, the system or mode of adapting steam engines for actuating screw
propellers direct by means of the combination of a long crank and short stroke
of piston.
Eleventh, the employment and use in steam engines of curved or bent
differential beams or side levers for the purposes herein-before described.
Twelfth, the employment and use of steam engines constructed as delineated
in Figures 3, 4, 5, 6, 7, and 8, for propelling vessels and other purposes.
Thirteenth, the employment and use of steam engines constructed as de-
lineated in Figure 10, wherein the piston rod connection is placed between the
fulcrum or main centre of the beam and the connecting rod centre for the
purposes herein-before described.
1
Fourteenth, the systems or modes of obtaining a superior length of con-
necting rod, or of lowering the beam in steam engines, as delineated in Figure
11, on Sheet 2 of my Drawings..
Fifteenth, the employment and use in steam engines of duplex or jointed
connecting rods as delineated in Figure 12, on Sheet 2 of my Drawings;
and the system or 'mode of working my duplex or jointed connecting rods,
as herein-before described, so as to produce the same effect as that obtained
from ordinary inflexible rods of a similar length.
Sixteenth, the system or mode of constructing double cylinder expansion
or Woolf's engines, wherein one cylinder is placed on cach side the main
working centre of the beam, the effective leverage of each, or of the larger
cylinder alone, being less than the effective working lever of the connecting
rod end.
Seventeenth, the employment and use of two short-stroked cylinders placed
one above the other to economise horizontal space in my differential beam
engines as herein-before described.
Eighteenth, the system or mode of obtaining superior uniformity of rate in
expansive steam engines, by providing that the momentum or inertia of certain
of the moving parts shall equalise the varying steam pressure or action.
Nineteenth, the system or mode of superadding weight to the pistons,
working beams, or other moving parts of steam engines which are com-
prehended between the piston and crank pin, or of adjusting the weight of
such parts, for the purpose of securing superior uniformity of rate.
Twentieth, the system or mode of regulating or adjusting the rate of steam

page_text: engines by the addition of a secondary action to the ordinary governing
apparatus.
Twenty-first, the system or mode of balancing the external steam pressure
on the backs of slide valves, by the action of fluid pressure from beneath.
Twenty-second, the system or mode of constructing valved pistons or buckets
and other lift or discharged valves as herein-before described.
Twenty-third, the application and use of flexible rings or annular discs for
buckets or lifting valves as herebefore described.
In witness whereof, I, the said James Whitelaw, have hereunto set my
hand and seal, the 29th day of January, in the year of our Lord One
thousand eight hundred and fifty-two.
Signed, sealed, and delivered by the
within-named James Whitelaw, in
the presence of
JAMES (L.s.) WHITELAW.
2
AND BE IT REMEMBERED, that on the Twenty-ninth day of January,
in the year of our Lord 1852, the aforesaid James Whitelaw came before
our said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according to
the tenor of the Statute made for that purpose.
Enrolled the Thirty-first day of January, in the year of our Lord One
thousand eight hundred and fiftee two