CERTAIN IMPROVEMENTS IN STEAM ENGINES AND IN PROPELLING
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
PEDDER, late of New Union Street, in the County of Middlesex, but now of
Church Street, Islington, in the said County, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Let-
ters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Sixth day of November, in the cleventh year of Her reign, did
give and grant unto me, the said James Pedder, my executors, administrators,
and assigns, Her especial licence, full power, sole privilege and authority,
that I, the said James Pedder, my executors, administrators, and assigns, and
such others as I, the said James Pedder, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time and at
all times hereafter during the term of years therein mentioned, should and lawfully
might make, use, exercise, and vend, within England, Wales, and the Town
of Berwick-upon-Tweed, and in the Islands of Jersey, Guernsey, Alderney, Sark,
and Man, and also in all Her said Majesty's Colonies and Plantations abroad, my
Invention of "CERTAIN IMPROVEMENTS IN STEAM ENGINES AND IN PROPELLING;"
in which said Letters Patent there is contained a proviso that I, the said
James Pedder, shall cause a particular description of the nature of my said
Invention, and in what manner the same is to be performed, by an instru-
ment in writing under my hand and seal, 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, reference being there-
unto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
James Pedder, do hereby declare the nature of my Inventions, and the
manner in which the same are to be performed, are particularly described and
ascertained in and by the following statement thereof, reference being had
to the Drawings hereunto annexed, and to the figures and letters marked
thereon (that is to say) :-
My Invention's consist, first, in causing two or more engines to work whose
motions are connected, and the revolutions of a crank or. wheel produced by
regulating the length of the throw to the length of the versed sine of an arc a
lever or pendulum describes in its vibration, and the length of the motion of
the versed sine or versed sine action communicated to a crank or wheel to cause
it to revolve. This I do because the most economical mode of working steam
is to work it expansively, and the way to do that to the greatest advantage is
to have a long stroke to the piston, but in all the purposes to which the steam
engine is applied a long stroke cannot be had. For example, in the loco-
motive engine the stroke is necessarily limited to a disadvantageous length for
working the steam expansively, because each revolution of the driving wheels
is produced by a double or full stroke of the piston, and to employ spur
gearing is not advisable. Now, two revolutions of a crank may be produced
with one double or full stroke of the piston, by communicating the motion of
the versed sine of the arc that a lever describes by its vibration; but in this
there is a difficulty to overcome, because the line that the piston rod describes
would equal the chord of the arc. Therefore, half the length of the stroke
would equal the sine, and one-fourth the length of the stroke would equal
half the sine. Now, by communicating the motion of the versed sine to the
crank or wheels, this one-fourth the length of the stroke of the piston rod
should equal half the throw, because there is a revolution produced in the
crank by the piston moving from one extremity to the other; but this cannot
be done when the motion is communicated from the versed sine, because the
length of the motion from the versed sine will approximate four-fifths of
the whole throw, that is, with the piston moving one-fourth the length of its
stroke. Now, with a single engine with a fly-wheel applied, a crank will
revolve under these circumstances, but the motion of the piston will not be
equable and uniform; therefore, for a single engine the versed sine action
would be a bad application, and two or more engines connected in the ordinary
way would not work. Therefore, to connect two or more engines together to
work with the versed sine action, the cranks must not be at right angles, but
must be at some other angle, and the length of the connecting rods found
.

page_text: from that angle. It is also adviseable to have two crank shafts, one to make
a revolution with each double stroke of the piston, and the other to be worked
by the versed sine action, and make two revolutions to each double stroke of
the piston, and the angles arranged accordingly. In the Drawings, Figures I.,
II., III., &c., the angles of the cranks actuated by the versed sine action are 120°,
and the angles of the cranks, making one revolution to each double stroke of the
piston, are 60°. Now, as the length of the motion produced by the versed
sine approximates four-fifths of the throw with the piston moving one-fourth
the length of its stroke, the crank actuated by the vrseed sine action will move
from its position (which it is in when the piston is at either extremity) 120°, and
the crank that is moved in the same time as the piston will move from its
position 60°. Now, the length of the connecting rod applied to this crank
(that moves in the same time as the piston) may be made to suit convenience,
the longer the better; but the connecting rod applied to the crank actuated by
the versed sine action must have its length found by taking the length of the
sine of the angles of the levers, also the length of the versed sine of the same
angle, when the piston is at either extremity. Then divide the length of the
sines by two, and find the length of the versed sines of the arcs, whose
sines are equal to the quotients of the divided sines, and subtract their sum
from the whole length of the throw; the remainder will be the length of
motion produced by the versed sine action when the piston has moved one-
fourth the length of its stroke, and this will approximate four-fifths the throw.
Now, take the sum of these last found versed sines, and subtract it from the
versed sine of the arc the crank has to describe in passing to the opposite
side to the same number of degrees, and the remainder assume as a versed
sine for the connecting rod; also assume the sine of the arc the crank has to
describe in passing to the opposite side for the sine of the connecting rod;
then by squaring the sine, and squaring the versed sine, and dividing their
sum by the sum of two versed sines, the quotient will equal radius equal the
length of the connecting rod. Note.-The crank passes to the same angle
on the opposite side, that is, according to the Drawings, from 120° to 240°,
which equal 120° reverse, and the piston will move from one-fourth the length.
of its stroke to three-fourths its length; and when the piston has moved from its
three-fourths position to the extremity, the crank will have passed from 240°
to 360°; and the crank, whose angles are 60°, will move 60° with the piston
moving its first fourth part of its stroke, and 60° further with the piston
moving from the first fourth part of its stroke to the third fourth part, and
will move 60° further, completing half a revolution, with the piston moving
from the third fourth part of its stroke to the extremity. So that with the

page_text: cranks at these angles, and the length of the connecting rods found as above;
the motions of the cranks will approximate the motions of the pistons,, and
thereby cause the engines to work with an equable and uniform motion.
Figure 1 shews the position of the cranks when the piston has moved one
fourth the length of its stroke.
.
Figure 2 shews the position of the cranks when the piston has moved from
the third fourth part of its stroke to the extremity.,
Figure 3 shews the position of the cranks when the piston has moved from
the first, fourth parts of its stroke to the third fourth part.
Various are the modes by which the versed sine action may be commu
nicated to a crank or wheel; but, in any mode of its application, the great
disproportion there is between the versed sine due to the whole sine at the
commencement of the stroke, and the versed sine due to the half, sine, or
when the piston has moved one-fourth the length of its stroke, renders it
impossible for two or more engines to work connected in the ordinary way.
Therefore, I lay no claim to the application of the versed sine action to com-
municate motion to a crank; but I claim as my Invention the arrangement
of the cranks by setting them at other angles than a right angle, and applying
connecting rods thereto, of a suitable length, when the motions of two or more
engines are connected that communicate the versed sine action to the cranks
to cause them to revolve twice for each full or double stroke of the pistons,
and which I call the versed sine double crank action engine, from the parallel
motion.
My next improvement consists in the application of an extra revolving
crank shaft to a locomotive engine; so that the shafts of the wheels axles can
be straight, and the motion communicated to them without placing the
cylinders on the outside, and this improvement I claim. This will enable
the cylinders to be placed under the boiler or between the wheels, thereby
lowering the centre of gravity without endangering the wheels axles. This
way of communicating motion to the wheels will be understood by reference to
the Drawings, where the same letters indicate similar parts. a, in Figures 4,
5, 6, 7, is the extra revolving crank shaft shewn applied; but I do not con-
fine myself to this position.
My third improvement consists in opening and closing the steam ports
instantaneously at any part of the stroke, for the purpose of working the steam
expansively or otherwise, by the application of a cam of three different lengths
of radii, and the changes from one length to another, to form rises and falls at
such distance as may be required to move the valves at the proper time,
instead of an excentric, as is ordinarily used; and this improvement I clam

page_text: This cam can be made in one or more parts to facilitate the adjustment of
the rises and falls. The application of the cam instead of an excentric` is
shewn in the Drawings, Figures 1, 2, 3, 5, 6. B is the cam in its position at
different parts of the stroke.
My fourth improvement consists in the application of extra wheels to the
front or back of locomotive engines or carriages, to run upon each rail, and so
connected to the locomotive or carriage that they will rise or fall without
disturbing them thereby; and these safety wheels I call pilot wheels, and this
improvement I claim. At each end of the axle shaft is fixed an arm or lever,
and these arms or levers are connected to the carriage frame with joint pins
or axles, so that the two wheels can rise or fall without disturbing the carriage,"
and the carriage rise or fall without disturbing the pilot wheels. Now, if these
pilot wheels were to come in contact with any hard substance laying upon¯
the rails, (if not too large,) they would pass over it without disturbing the
carriage, and immediately fall to their proper place upon the rails, and the wheels
of the carriage would then pass over the substance without disturbing the
pilot wheels, and fall to their place upon the rails; and the carriage would
pass along the line without being in danger of running off, because when the
pilot wheels were up, the carriage would govern them during their fall, and
when the carriage wheels were up; the pilot wheels would govern the carriage,
and cause the carriage wheels to fall to their proper place upon the rails."
The pilot wheels can be applied to the front and back of the carriage, so that
they would govern the carriage in its movements backward or forward. In:
the Drawings a mode of their application is shewn Figures 5, 6, 7, 9, 10, 11.1
O is the arm or lever connected to the frame of a locomotive engine or car-
riage; P, pilot wheel connected thereto, as described.
My fifth improvement consists in placing at that end of a boiler where the
hot gases are emitted a water-chest, kept always full, having a tube or tubes fixed.
in it, to allow the hot gases to pass through on their passage to the chimney,
so that the water surrounding the tubes may absorb a portion of their heat
previous to its entrance into the boiler. To effect this the water is pumped
into the chest, or (as I shall call it) separate absorber, and the boiler is
supplied from the separate absorber by the surplus water forcing itself through
an aperture or pipe having a valve in it opening boilerward, so that the water
in the separate absorber is always under as great a pressure as that in the
boiler, and this improvement I claim. In the Drawings the separate absorber
is shewn applied to a locomotive boiler. Figure 5 x is an intervening
smoke box, in which the hot gases enter previous to their entrance into the
tubes of the separate absorber; y is the separate absorber, with a number of

page_text: tubes in it for the hot gases to pass through on their passage to the chimney;
z, the pipe, with a valve in it that will open towards the boiler for the surplus.
water to pass through from the separate absorber to the boiler.
My sixth improvement consists in the formation of a rotary engine or pump,
with two different lengths of radii struck from the same centre, and the difference
of their lengths formed into a passage for the steam or water or other fluid, and
the sum of the two radii, divided by two, to form the length of the third radius
with which to describe the arcs connecting the greater external arc on each
side with the less, thereby forming an external boundary whose diameter
through the centre, (from which was struck the greater and less arcs,) shall
be equal to the sum of the long and short radii; so that if a bar whose length.
equals this diameter were put into a space thus circumscribed, it would
necessarily cross the centre from which the greater and less arcs were struck,
and if rigidly connected to a shaft in this centre, and at right angles to the
bar, the bar would then form the long and short radii, and the motion of the
shaft would be limited to the length of the arcs struck from this centre with
the long and short radii. But if the bar were made to pass through the shaf,
or the shaft to pass through a slot in the, bar, so that the bar could slide back-
wards or forwards at right angles to the shaft, then will the shaft be capable
of revolving, and the external boundary govern the bar, and cause it to slide
backward and forward, and will thereby form a moveable or sliding diameter.
Now, if a drum be fixed upon this shaft whose radius equal the less radius,
and if two or more bars, whose lengths are each equal the sum of the long
and short radii, are made to slide through its diameter, and the whole be
properly fixed in a box with a boundary, as above described, and the depth
of the box equal the width of the ends of the bars, and if in the two parts of
the boundary of the box that is described with a radius equal half the length
of the sum of the long and short radii there be made slots the whole length
of those arcs for the ingress and egress of the fluid, and if there be suitable
packing to confine the fluid in its passage to the space in the box unoccupied
by the drum, then it will act either as an engine or a pump, and the sliding
diameters will perform the office of pistons, if for an engine to be acted upon
by the fluid, and if for a pump to act upon the fluid.
In the Drawings,
Fig. 12 is an elevation; Fig. 13 is a plan; Fig. 14 is a longitudinal section,
and 15 is a transverse section. The letters r, r, r, are stuffing boxes in the
drum, with packing on each side of the piston, and s, circular recess, with a
loose ring fixed in it, adjusted by screws through the outside case, to cause it
to press upon the packing placed in the recess between the loose ring and the
drum, so that it forms an annular stuffing box; and there being one on each

page_text: side of the drum, and a stuffing box on each side of the pistons, there can be
no escape of the fluid into the drum; and if the pistons are packed with
suitable packing, there can be no escape of the fluid at the ends or sides of
the pistons. Fig. 16 is a longitudinal section of piston upon a magnified
scale; Fig. 17, transverse section of piston and stuffing boxes, upon a
magnified scale. Now, I claim, as my Invention, the form of a case
for a rotary engine or pump whose circumscribing boundary has two arcs
in it described by two different lengths of radii from the same centre,
diametrically opposite to each other, and of sufficient length to span from
piston to piston, (there not being less than four pistons, and these con-
nected in pairs, and placed at equal angles through the centre from which the
two arcs are struck,) and these arcs connected together at each end by an arc
having a passage its whole length in it to admit or emit the fluid, so that the.
four arcs form a boundary capable of allowing a diameter to rotate in it whose
length is equal to the sum of the long and short radii. I claim also the
application of an annular stuffing box to a rotary engine or pump, with an
adjustable ring, whether to press upon the packing or it be a ring of metallic
packing. This rotary engine is shewn applied to a locomotive engine, which
I call the rotary locomotive engine. Fig. 25 is a section of the same, with a
separate driving shaft f, having my rotary engine built upon it, for the
purpose of communicating motion to it, and the motion of this shaft com-
municated to the wheels to propel the engine. The steam can be admitted
and emitted either way, and the change produced by moving the lever that is
connected to the valves. g is one of the rods that communicate the motion of
the shaft to the wheels; h is the lever and its connections to the valves for
effecting the changes and stoppage.
My 7th improvement consists in the discovery and in the proper application
of the force of the vis viva of a jet of water acting by unbalanced pressure, as the
medium of transmitting steam power to propel vessels and locomotive engines.
which I call hydro-dynamical propulsion, and this improvement I claim. Now, it
was not known until my discovery that a column of water fixed in a move-
able position, whose area is considerably larger than the area of the orifice, and
the orifice nearly at the bottom and at right angles to the vertical column,
and in a thin plate, (and not through a cylindrical tube,) and to which a
weight is attached with a string over a pulley, that the water issuing therefrom
will sustain a weight equal to two altitudes into the area of the contracted
vein, and into the density, which is twice the hydrostatic pressure. Now, a
vis viva, which equals the quantity into density, divided by the final velocity

page_text: of the first second of a falling body (which is 32-19084 feet) into the square
of the velocity, is inherent in a discharge through an orifice in a thin plate, and
is capable of producing a mechanical effect equal to half the vis viva, (less
about six per cent.,) which equals the altitude into the velocity, into density,
and into the area of the contracted vein, less about six per cent. But if the
water issues through cylindrical tubes, the loss of mechanical effect will be
eight times as great as for efflux through orifices in thin plate, or through an
orifice in the form of the contracted vein; and this loss is with short tubes.
But if the tubes be long, the loss is considerably greater. I wish it to be under-
stood that a mouth-piece whose length is less than its diameter I do not con-
sider a tube, because the water would not touch the sides. Now, a column of
water issuing through a horizontal orifice in a thin plate being capable, as I
discovered, of sustaining a weight equal to two altitudes, without the column
itself moving, it follows that to produce an useful effect the weight must be
less, and the column move, and that the maximum will be when the weight or
resistance overcome into the velocity of the vessel will equal the mechanical
effect due to the velocity of the issue into the altitude, into the density, and into
the area of the contracted vein. So the weight or resistance to be overcome
may be so great that the velocity of the vessel would be so small in proportion
to the velocity of the issue as to be working at a great loss, and if the water
issue through cylindrical tubes or pipes, these losses are eight times greater.
Now, if the weight or resistance to be overcome, which is the constant pressure,
equal one and a half altitude, due to the velocity of issue into the density, and
into the area of the contracted vein, then will the velocity of the vessel approxi-
mate two-thirds of the velocity of the issue, that is, the velocity of the vessel
will be between one-half and two-thirds of the velocity of the issue, if the efflux
is through an orifice in a thin plate, and the orifice small in proportion to the
size of the water chest from which it issues. Now, if the constant pressure or
resistance to be overcome equal one and three quarters altitude, due to the
velocity of the issue into the density and into the area of the contracted vein,
the velocity of the vessel will approximate one-half the velocity of the issue.
Now, one and three quarters into one-half equals seven-eighths of the mechanical
effect, and one and a half into two-thirds equal one, equal the whole mecha-
nical effect, and one and a half into one-half equal three-fourths, the mechanical
effect equal seventy-five per cent., and the vis viva so applied will do this and
have a surplus of power if the efflux is through an orifice in a thin plate, and
issues into the atmosphere; but if it issues under water the orifice is best in the
form of the contracted vein, and there will be a loss of one and a half per cent.

page_text: 6,720 lbs.
64
105 and
105
24
in the altitude due to the velocity of the issue, but even with that loss it would
still do its work of seventy-five per cent., and have a surplus of power. If,
therefore, the vessel had to contend against a current, and thereby increase its
resistance and decrease its velocity, the power of the issue would increase, and
would overcome any resistance less than two altitudes into the density and into
the area of the contracted vein; so that when the resistance equalled two alti-
tudes, the vessel would not move. To give an example for finding the area of
the orifices I will take "the Rattler," whose constant pressure at ten knots
per hour, or sixteen feet per second, equals three tons, equal six thousand seven
hundred and twenty pounds. Now, a cubic foot of salt water weighs sixty-four
pounds, and if the velocity of the vessel equal half the velocity of the issue, the
velocity of the issue must equal thirty-two feet per second, and the altitude due
to this velocity is sixteen feet. Therefore an altitude and half will equal
twenty four feet; therefore 720
4,375, equal the areas of
the contracted veins of the two orifices, so that the area of the contracted vein
of each orifice equals 2,1675 feet. Now, to propel with economy, the relative
velocities of the vessel and the issue must be kept within certain limits.
Therefore, as regards relative velocities, I claim the propulsion of vessels by a
jet of water, the velocity of which is not greater than three times the velocity
of the vessel. To take advantage of water propulsion I propose to use the
water to assist in the condensation of the steam previous to its being ejected
for propelling the vessel, and this I do to save the whole of the distilled water
by making the drum of my rotary pump a condenser. To increase the metallic
surface on the inside I have hollow projections cast in the rim pointing towards
the centre, so that their cavities are always filled with cold water, and thereby
present a large area of cold metallic surface to the steam in the condenser.
Aware, however, that steam condenses quicker when it comes in contact with
water, I admit the steam nearly at the top of the condenser, and emit the
condensed steam into the feed pump. Through a pipe, a certain distance from
the bottom on each side of the drum, are holes to form a communication with
the space between the drum and the case and the interior of the drum. This
condenser would hold a quantity of water in the part below the point of emission
that could not be drawn out by the feed pump, and the broad ends of the
pistons being the whole width of the drum, and there being always a certain
length of the broad part in the drum, it follows that as the drum moves round,
the pistons will carry the water along with them a certain height inside the
drum, and then allow it to fall, so that the water is dashed amongst the steam.
and against the cold metallic surface of the condenser, thereby facilitating the

page_text: condensation. To produce a vacuum, the steam is blown through, and a vessel
of water placed above the condenser, with a pipe leading from the bottom of this
vessel to the top part of the condenser, and the condenser being full of steam,
the tap is turned, and the water allowed to flow from this water vessel into the
condenser amongst the steam to condenṣe it, and thereby produce a vacuum.
Now, this water will occupy the lower part of the condenser, and be acted upon
with the pistons and motion of the drum before shewn, and, when necessary,
by turning a tap placed at the bottom part of the condenser and the tap
in the pipe leading from the water vessel to admit the air, the water can
be drawn out of the condenser and put into the water vessel, and the steam.
blown through and this water re-admitted as before, and a vacuum produced
for starting. Now, the rim of the drum having the hollow projections in it,
and continually coming in contact with a fresh quantity of cold water passing.
through the pump, and a quantity of water always kept dashing about amongst
the steam and upon the large area of cold metallic surface, the steam will be.
condensed with great facility, because this condenser partakes of the properties.
both of injection and surface condensation, and saves the whole of the distilled
This condenser can be applied to a paddle wheel that works outside the
vessel, and propels the vessel by the paddle boards acting upon the water in the
ordinary way, by fixing partitions in the inside of the drum, instead of the
pistons, to keep the water in agitation amongst the steam, and the steam
admitted and the condensed steam emitted through passages made in the
shaft, and escape prevented by stuffing boxes.
water.
I claim as my Invention the application of a condenser for the condensation
of steam, having the compound properties of water and surface condensation,
that will save the distilled water. Figure 18 is a longitudinal section of the
pump and condenser, and water chest or jet propeller. Figure 19, plan;
Figure 20, elevation. c, condenser; d, passage in the pump for the water;
f, pipe leading to the water chest or jet propeller; h, water chest or jet pro-
peller; i, the jet orifices; ;, air vessel; c, red lines shewing the position of the
water chest or jet propeller if the water issues into the atmosphere, and the
valves closing the jet orifices below the water line, which the water would open
when the vessel was propelled the contrary way. Now, with the jet propulsion
the steam can be brought in contact with the water previous to its entrance.
into the pump, and be condensed and become part of the water emitted for
propelling the vessel. This is shewn in its application to the propulsion
of locomotive engines with a jet of water, for whose range there must be
sufficient length of tank to prevent impingement at the end opposite the point

page_text: of issue, because the distance the water will spout is equal to two root of the
altitude, due to the velocity of the issue into the height of the orifice above
the horizontal plane. But the length of the tank shewn in the Drawing will
allow a range of issne necessary for the propulsion of a train from thirty-five to
forty miles per hour.. Figure 21, longitudinal section; Figure 22, sectional
plan; Figure 23, plan; Figure 24, transverse section. b, steam .cylinder;
m, water cylinders; n, steam pipe; u, steam chests; v, pipes connecting the
two jet propellers; w, the upper part of the jet propellers for an air, vessel;
9, the jet orifices; a, valves; b', frame for connecting the valves.to be opened
or closed at pleasure by the conductor; c', exhaust pipes; d', water chest for
the water to enter through the pipe from the tank... As this water chest forms
the condenser in which the vacuum is produced, and will be, exhausted
without the usual air pump, I call it "the self-exhausting condenser.".. e' is
the valve, which is. occasionally closed by a cam that is.a little before the close
of the stroke, and thereby shuts off the pressure of the atmosphere; the water,
therefore, in "the self-exhausting condenser" will by its gravity follow the
piston in the water cylinder, and leave a vacuum in the self-exhausting con-
denser, and also cause the stroke to be completed without violence, the same
as the cushioned steam in the Cornish engine; and as the cam does not revolve,
but returns, the piston will return the same distance back, before the valve opens,
as it had to go to complete the stroke when it closed; so that the water left in
"the self-exhausting condenser." will go into the other cylinder, and the steam
at the same time will be entering the vacuum, and when the valve is opened
the water from the tank will rush into the "self-exhausting condenser," and
condense the steam, and the operation will be repeated every stroke. Thus at
the close of the stroke the atmospheric pressure is cut off, which steadies the
motion, and at the commencement it is kept off, when the steam is at the full
pressure, before it is cut off for expansion. In this way a vacuum is produced,
and the steam condensed with the water that is used for propelling. Now,
this water, if it were not used for propelling, would get too warm for the purpose
of condensing steam, but by the velocity with which it is brought in contact
with the atmosphere at the point of issue, it will be kept sufficiently cold. The
feed pump is here shewn worked by an excentric applied to the wheels of the
boiler carriage.
I
I claim generally, as regards locomotive engines, the application of the water
they carry as the medium of transmitting the steam power to propel them.
also claim, for propelling vessels and locomotives, a chamber or chest, which
I call the separate jet propeller, into which to force the water under the

page_text: required pressure, to cause the water to issue from it with the necessary velocity.
I claim also for jet propulsion a pipe who area of supply, in reference to the
area of its contracted orifice, shall be equivalent to the separate jet propeller.
I claim also mere common holes, that is, flat plate holes, in the said chest
or jet propeller or equivalent pipe, for the discharge of a jet or jets of
water. I do not confine myself to this form of orifice, but I greatly prefer it
when the jet issues into the atmosphere; when, however, the jet issues under
water, I prefer contracted vein orifices for its discharge, which I claim. I
claim also the arrangement of the machinery described for hydro-dynamical
propulsion, but do not confine myself thereto. Lastly, I claim generally for all
engines for raising water, or for propelling by it, the use of the same stream
of water raised, to be expelled or for propulsion, to condense the steam as well
by surface as by injection or mixing with it. I claim also for all such engines
the use of "the self-exhausting condenser," not confining myself to the parti-
cular arrangement of valves shewn. This method of condensing applied to
hydraulic engines will dispense with their ordinary air pump, whilst it will
add to hydraulic high-pressure engines the force of a vacuum without the
addition of the ordinary air pump. Hydro-dynamical propulsion, instead of
propelling by paddle wheel or screw, will afford considerable security against
the dangers of navigation, leaks, and fires, to subdue which the whole power
of the engines will be available. On springing a leak the external water for
propulsion will be prevented entering by closing a valve or cock, and a com-
munication being opened through the bilge pipe between the hold and the
supply pipe leading to the propelling pump, the water for propelling will be
drawn from the hold as it enters through the leaks, and be expelled. Thus
the entire engine power will be exerted to keep the leaks under, and to propel
the vessel at the same time. On spontaneous combustion of cargo, or other
fire, the pipe from the propelling pump will be closed, and the water, which is
drawn in as usual, will be used for subduing the fire instead of for propelling;
and as it runs into the hold it can be withdrawn through the bilge pipe, and
so be used again and again to prevent the water rising high enough to put out
the boiler fires. Thus the propelling, fire, leak, and bilge pumps are combined
in one. The above comprise my "improvements in steam engines, and in
propelling."
In witness whereof, I, the said James Pedder, have hereunto set my
hand and seal, this Sixth day of May, One thousand eight hundred
and forty-eight.
JAMES (L.S.) PEDDER.

page_text: AND BE IT REMEMBERED, that on the same Sixth day of May, in the
year above mentioned, the aforesaid James Pedder came before our Lady
the Queen in Her Chancery, and acknowledged the Specification aforesaid,
and all and every thing therein contained, in form above written. And also
the Specification aforesaid was stamped according to the tenor of the Statute
in that case made and provided.