IMPROVEMENTS IN STEAM ENGINES, STEAM BOILERS, AND FURNACES OR FIRE-PLACES
Year: 1844

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I MOSES
POOLE, of Lincoln's Inn, in the County of Middlesex, Gentleman, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Fourteenth day of March, in the seventh year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said
Moses Poole, Her especial licence, full power, sole privilege and authority,
that I, the said Moses Poole, my exors, adñiors, and assigns, or such others
as I, the said Moses Poole, my exors, adñiors, 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 "IMPROVEMENTS IN STEAM ENGINES, STEAM BOILERS, AND
FURNACES OR FIRE-PLACES," communicated to me by a certain foreigner residing
abroad; in which said Letters Patent is contained a proviso, that I, the said
Moses Poole, shall cause a particular description of the nature of the said
Invention, and in what manner the same is to be performed, to be inrolled
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, as in and by the same, reference being thereunto had, will more fully
and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Moses Poole, do hereby declare the nature of the Invention, and the manner in
which the same is to be performed, are fully described and ascertained in and
by the following statement thereof, reference being had to the Drawings here-
unto annexed, and to the figures and letters marked thereon (that is to say) :-
The improvements consist, first, in a mechanism which I call clearing
apparatus, which is adapted below the grate of the fire-place for the purpose of
clearing out the fire and facilitating the introduction of air into the fuel.
Second, in the employment of an apparatus to generate steam from the water
drawn out of the boiler with the steam, and to regulate the temperature of the
dry steam. Third, in the arrangement of a tubular generator with interior
fire-place, constructed in a very simple way, and easy to clear. Fourth, appa-
ratus destined to prevent explosions in steam boilers. Fifth, in an apparatus
to regulate and moderate the speed of steam engines, whatever may be the
variations of the moving power and the resistance thereto.
DESCRIPTION OF THE CLEARING APPARATUS FOR THE GRATE.
Figure 1 in Drawing N° 1 shews the apparatus adapted to the fire-place
of a large copper, having two boilers. Figure 2 is a plan, the frame having
adapted to it projecting arms, which are destined to penetrate into the fire
passing between the fire bars. There are only shewn upon the frame half the
number of projecting arms that would be required to clear it out at a single
action; but I prefer that it should be done twice. Figure 3 shews the me-
chanism, which, by the help of the handle D, serves in changing the position of
the frame after the projecting arms have passed once into the fire between the fire
bars. In all the Figures the same letters indicate the same parts. A, A, is the s
frame, having its bent projecting pieces a, a, a, a, a, of the frame. B, B, B, B
are levers or iron rods, to set in motion the frame clearing apparatus for
the grate. b, and c, are the axes of support and articulations of the apparatus.
e, e, is a counter weight nearly balancing the frame. C, C, are the rods which
suspend the apparatus and give the clearing grate apparatus a horizontal s
motion when its projecting arms have penetrated into the bed of the fuel.
ffff, are arms, making part with the levers B, and are connected together
by means of the cross piece 9, 9, forming a handle to work the apparatus.
D, shewn at Figure 3, is a handle to change the position of the frame A from
right to left, or from left to right, in order that in time the projecting arms s
may pass through all the empty space between the fire bars. E, Figure 1, is
a small roller upon which the frame rests when it is in its lowest position, and
which enables the frame to be easily changed without shaking and without

page_text: much effort. F, F, F, bent piece, to limit the extent of the to-and-fro hori-
zontal movement of the frame. G, G, are the fire bars. h, h, are supporters
to the fire bars to avoid their deformation. It would be best to increase the
number of these supports and so to arrange them that the bars should fit one
into the other, in order to render them more solid; by this means the destruc-
tion of the bars will be avoided, which might some time otherwise occur, and thus
prevent the functions of the clearing grate apparatus. i, i, shew the bent ends
of the fire bars. These are kept in two small troughs always full of water, which
may be kept full by any of the well-known apparatus for supplying water to
vessels. The object of the water is to keep the fire-bars from attaining too
great a temperature and deforming; or in place of this arrangement, hollow
fire bars may be employed, with water or steam passing through them. The
mode of working the clearing grate apparatus is as follows:-By pressing
slightly upon the crossing pieces B, B, the projecting arms will be forced up,
and enter between the fire bars into the body of the fuel. Then, by giving the
cross piece B a horizontal movement, the fuel is broken and raked about, and
the ashes caused to fall down. The frame of the clearing apparatus for the
grate should then be changed by means of the handle D, so that the projecting
arms should enter between those bars which had not been cleared by the first
operation; the handle must then be caused to act after having lowered the
frame. In order to prevent the boilers from being burnt by the direct action
of the flame upon them, I construct a small brick arch, as thin as possible,
shewn at H, H, in Figure 1, above the fire-place, or merely remove the fire
bars from the boilers.
I will now describe the clearing apparatus for the grate applied to loco-
motive engines. The Figures 1, 2, 3, 4, of Drawing No 2, shews the clearing
apparatus for the grate adapted to a locomotive. Figure 1, Drawing N° 2,
shews a vertical and longitudinal section of the fire-place, and of the back
part of a locomotive, having the clearing apparatus for the grate applied
thereto. Figure 2 is a view of the same engine, shewing the back part of it,
and where the cross piece of the frame has been taken off. Figure 3 shews in
plan part of the mechanism when in its place; a part of the iron plate is taken
off to shew the mechanism. Figure 4 is a plan of the frame clearing appa-
ratus. The clearing apparatus acts with the fire-place in the same way as
with other engines, but the mode of working the frame is different; because
the firemen in locomotives are placed upon a platform much above the ash pan,
whilst with the other engines the firemen are placed on a level with the bottom
of the ash pan. A, A, seen at Figures 1, 2, and 4, is the frame clearing
apparatus with its projecting arms. D, shewn at Figures 1, 2, 3, is a pedal

page_text: on which the engineer presses with his foot when he requires that the arms of
the apparatus should enter amongst the fuel. The motion is communicated by
means of the lever E, E, E, and the rod F, acting upon the small arm A', which
supports the frame clearing apparatus for the grate. G, shewn at Figures 1,
2, and 3, is a lever handle, which acts upon the frame and gives the horizontal
rocking to-and-fro motion, when the projecting arms are between the fire bars,
by means of a shaft H, H, and the rods I, I, Figures 1 and 2, making the
suspension of the frame. The course of the lever G is limited by the conical
notch J, J, in which the pin K. moves; which pin may be fixed more or less
low, according to the length of course required. L is a handle by which the
change is made in the position of the frame when it is necessary to clean those
parts of the fire-place which have not been done by the first operation.
By turning the handle, motion is communicated to the frame through the
rack M, and the small lever N, which acts on the rods which suspend the
frame, and thus cause the necessary change of position. O, shewn at Figures
2, 3 and 4, are counter weights, to act as balances to a part of the weight of the
frame. A second counter weight may be placed upon the rod E. This rod E
may be increased in length beyond the point of junction with the rod F, so as
to carry the weight further from the fulcrum of the lever, by which arrange-
ment a small weight will do. The same results may be obtained by other
means than those I have described to act upon the fire-places. For example,
instead of causing the projecting arms to enter between the fire bars, I can, by
means I will now describe, raise alternately by one of their ends all the bars
of the grate, which would have the same effect upon the fuel to stir it, and to
cause the ashes to fall down. The means I propose to employ for the purpose
of raising the ends, one after the other, of the fire bars, or several of them
together, arc, first, to employ a mechanism almost similar to that of the
clearing apparatus, but with this difference, that the frame, instead of being
furnished with a number of projecting arms for penetrating into the fuel,
should have a single row of forked or bent arms to raise the bars; by this
means one-half of the bars would be raised at one time, and the position of
these forked pieces might be changed so as to raise the other bars by the
arrangement of machinery before described. With this mode of raising the
bars, the mechanism for giving the to-and-fro motion to the projecting arms
would be dispensed with. Another plan for raising the bars would be by
employing a cylinder, having thereon a series of cams, which being turned by
means of a handle would raise the bars one at a time.
I will now describe the apparatus to turn into vapour the water which is
drawn from the boiler with the steam, and also for regulating the temperature

page_text: of the dry steam. Experience has shown that in all steam engines, more
especially when applied for locomotive purposes, that there is a considerable
loss of useful effect arising from, first, the water drawn into the cylinder with
the steam by the effect of boiling; second, in the cooling and partial con-
densation of the steam in the cylinders, and in the tubes along which the
steam passes. The object of the clearing apparatus before described will be
to increase the intensity of the fire, and consequently the ebullition; it will
thence result, from the use of this apparatus, that a greater quantity of water
will be forced into the cylinders with the steam. The means that I propose to
prevent this evil, are as follows:-First, to heat again the steam coming from
the boiler, and thus turn into steam any water that may come with it, and to
prevent the condensation in the tubes and cylinders. To heat again the steam
as it passes from the boiler, it must be passed through a coil of pipes or any
convenient method of getting a large surface, and should be placed in the vent
holes in the interior of the chimney. By this means there will be the advantage
to increase the heating surface and to employ usefully a part of the lost heat.
The steam thus reheated will be conducted to the steam chest for distribution;
but as this steam should not have a greater degree of temperature than the
steam in the boiler, or only some few degrees more, otherwise the tow for stuff-
ing would be burnt and the oil for lubricating would be dried up, in order
to obviate these inconveniences, I have a short thick tube communicating with
the steam boxes into which the steam from the boilers, bringing with it the
water, as usual, also enters; the tube which conveys the reheated steam com-
municates also with the short thick tube; it will thus result that the reheated
steam will become mixed with the same steam coming from the boiler before
it arrives at the steam boxes. There should be placed a cock at the tube which
brings the reheated steam into the large tube, and also on the tube which con-
veys the steam and water from the boilers to the thick tube, and by opening
the one or the other of these cocks the temperature may be regulated, and the
excess of heat will be employed to vapourize the excess of water with which it
is saturated. If the reheated steam possesses more heat than is sufficient to
vapourize the water drawn in with the saturated steam, it may be passed
through water kept in a separate vessel, or even in the tube where the two
vapours are mixed together. It will be ascertained after the mixing of the
steam what the temperature is, and whether it is mixed in suitable proportions.
To ascertain the temperature, I place in the large tube a thermometer similar
to what I shall hereafter describe in speaking of the apparatus to prevent
explosions in boilers, shewn on the steam tube of the boiler, Figure 1, Drawing
Nº1, the arrangement I have just spoken of, furnished with its thermometer.

page_text: The thermometer may be supplied by a metallic thermometer, which will
open or shut the cocks or one of them, in order to maintain the mixing in the
proper proportions and temperature. In this case it will be better to employ
slides or valves, similar to those used to regulate the admission of the steam.
By the use of the means which I have described for drying the steam a great
economy of fuel will be obtain, and a great increase of moving power.
I will now describe my tubular generator with interior fire-place, fit to
receive a clearing apparatus, and more especially to steam vessels. The
machines that I have before described to increase combustion, as applied to a
locomotive and stationary engine, may be also applied with advantage to engines
on board steam vessels. The size of the boiler may be varied and the shape
altered as may be required. Figures 5 and 6, Drawing No 2, represent a
boiler for a steam boat, to which the clearing apparatus may be applied.
Figure 5 is a longitudinal, and Figure 6 a transverse section of the generator.
A, A, A, A, is the big cylinder making the external casing of the boiler; B, B.
is a cylinder vertically placed on the boiler of which it depends, and forming
the steam chamber; C is the furnace or fire-place; D is the ash-pit;
E, E, E, E, E, E, E, are the tubes of the boiler, for the passage of smoke. They
are like those usually used in a locomotive engine boiler, but these last are
smaller. F is a man hole; G is the steam chamber; H is the float (which
will be described hereafter); this float I prefer to be placed in a thin metal
cylinder having a quantity of holes perforated therein to decrease its weight;
I is the pipe to supply the boiler; J is the pipe for the passage of steam to the
cylinder; K is a small stopper, which is to be moved when it is required
to remove any cinders that may be deposited in the space L; M, M, is a box
or case, in which a man may enter when it is required to clean out the smoke
tubes; N, N, is the chimney.
I will now describe the apparatus for preventing explosions in boilers.
Figure 7 shews a section of the safety apparatus, which will be connected
with the steam boiler at the part marked O. In this apparatus there is a safety
valve and an ordinary float. a is a safety valve which produces a whistle
when the steam is escaping. This valve gives notice, first, when the steam is
of a pressure greater than is necessary; second, when the water descends
below the proper guage.
The action of the apparatus in these two cases is as
follows: The steam, when at a greater pressure than is required, passes away
through the valve and through a bell-mouthed piece b, and by pressing against
the angular sides, produces the whistling noise; and when the water has
descended below the proper guage, the float H, by means of the lever and the
forked piece C, C, opens the valve, which produces a whistling noise, as before

page_text: explained, with this difference, that the noise, instead of being continuous, is
intermittent, by reason of the ebullition of the water which agitates the float.
The advantage of this is, the cause of the whistling may be readily ascertained,
whether proceeding from too great a pressure of steam, or the water having
got below the proper level. The screw d, which is placed at the lower part of
the forked piece C, is to regulate the apparatus when the valve is too soon or
too late to shew the effect of the decrease of the level of the water. Figure 8
shews a vertical of the whistling valve on a large scale, as for execution.
A, A, is the seal of the valve fixed to the apparatus; B, B, is the valve or
moving part; C, C, is the bell piece forming the whistle; D, D, is a steel rod,
ended as a knife by the top connected to the lever E, which lever E presses on
the valve; F, F, is the axis of the lever E, and is also in the form of a knife,
and made of steel. The result of these shaped knife bearings acting upon the
parts of tempered steel is, that the valve moves freely. It should be remarked,
the moveable part B of the valve is larger at the upper part than at the lower,
which produces an increased force upon the valve when the steam raises it, as
when the steam acts against a greater surface. It results from this, that the
valve will be sufficiently open to allow of the steam produced to escape in such
a manner that the pressure of steam in the boiler should be more constant,
which is not the case with the ordinary valves. Figure 4 of the Drawing
No 1 shews another whistling apparatus, applicable to generators supplied with
the clearing apparatus, whereby the stean, being generated very rapidly,
explosion of the boiler would be more likely to take place if there were not a
good safety apparatus applied thereto. This apparatus is capable of giving
notice when there is too little water in the boiler, and also when there is too
much. This double advantage is obtained by means of a small valve, which
works by means of two floats, the one of which, by its own weight, opens the
valve when the water evaporates, and the other opens the valve when the
water encreases and loses part of its weight, and the valve in opening, allows
the steam to escape, and by rushing against the sides of a similar bell to that
before described, makes a great noise, which gives notice that the water in the
boiler is either too high or too low. A, Figure 4, is the valve; B is the float,
which acts in opening the valve when the water has descended below the
proper level; C is the float which opens the valve when there is too much
water in the boiler; D is a weight to equalize a part of the weight of the float
C, which should be of a given size and weight, whose weight should be too
large if the material of the two floats be of the same density. The liquid
should never arrive at the weight D. E, E, is the whistling bell; F, F, is a
disc, around which the steam passes, to press upon the sides of the bell; G, G,

page_text: a
is a spring to balance the float B, in case the float C, which is a counterweight
to it, should be made hollow or of a light material. This spring holds the float
B by means of the red H, I, the upper end of which is screwed to take into
the eared screw I, I, and in the cover J, J, which presses upon the spring G.
The spring may also be employed to balance the float B when the float C is
not employed. In place of the ordinary thermometer, a thermometer may be
applied composed of a metal tube closed at one end, and which may contain
mercury or any other fusible alloy. This may be placed about three-fourths of
its length into the boiler, and by placing good mercury thermometer, which
will indicate the pressure of the steam by its temperature. In order to
graduate properly the therirometer, I would recommend the work of Messrs.
Arage & Dulong, who have made known the relation which exists between the
temperature of steam and its pressure. This apparatus is shewn upon the
steam pipe of the boiler, Figure 1, Drawing No 1. The defect in the usual
centrifugal governor is, that when the balls have been moved beyond their
original position, either to open or shut the valve, they cannot return to their
original position without again changing the state of circumstances which
caused them to move. The object of the apparatus is to avoid these incon-
veniences. A, A, Figure 5, is the ordinary governor; B are the balls; C is a
rod which connects the apparatus to the ordinary governor, and by which the
motion is communicated to it; D, D, D, D, is a fixed frame; E, E, is another
sort of moveable frame, which slides on the frame D; F, F, is a rod, which
communicates the movement of the frame E to the valve G; H is a counter-
weight to the frame E; I, I, is an iron rod, which moves the frame E. This
rod has projections a and b on it, which work against the sliding pieces cand d.
These are arranged after the system of click and spring work of Mr Dobo;
they slide when pressed in one way, but are fixed when pressed in the other.
A represents one of these pieces, shewn full size at Figures 5, 7, and 8. a and b,
in Figure 7, are the appendages or notches. The piece A slides when pressed
on the part a, and resists when pressed upon the part b. e, e, and f, f,
Figure 5, are the appendages of the pieces c and d. g, g, are projections fixed
to the frame D; h, h, are springs to bring back the pins c and d to their
places. These springs act by means of a forked piece upon the rod around
which they are rolled. Figures 9 and 10 shew this forked piece full size. i, i,
are small cast springs, to cause a friction on the moveable frame. The mode
in which the apparatus acts is as follows:-The different parts are represented
in the Drawings in the state they would be when the engine was working at
the usual pressure, load, and speed; the two projections a and 6 of the rod I,
resting upon the two shoulders c, e, of the catches, and the other ones ff,

page_text: resting on the two fixed projections g, g, of the frame D. In this state the
valve G is half opened. I will suppose that it is required to increase the
pressure of the steam, or that the resistance is decreased; then, as soon as the
balls of the governor are extended, the rod I, I, will be raised, and draw up
the moveable frame E, E, which will shut more or less the valve G by means
of the rod F. The rod I acts upon the moveable frame by means of the
catcb c, which has resisted the pressure of the projection b. During the time
the catch & remains in its place, its shoulder f, in pressing against the fixed
projection 9, prevents its following the moveable frame, and moves in its
groove, and compresses the spring h'.
As soon as the governor has closed the valve the speed of the engine is
checked, and the balls can again approach each other without opening the
valve; for this reason, that the catch d, which has remained in its place, will be
at a distance from the projection a, which is the cause of opening the valve.
(This result cannot be produced with the ordinary governor, where every move-
ment acts upon the valve. But if the governor had at first closed too much
of the valve, and if the speed of the engine gets below the speed at which it
was started, then the projection a will press upon the shoulder e, and will open
the valve to allow the steam to pass through in sufficient quantities to keep up
the original speed. The springs h, h, are for the purpose of bringing down the
catches to their original position when the projections g, g, do not oppose them.
The small springs i, i, are destined to cause a friction from the moveable
frame E, E, on the fixed frame D, D; this friction serves to counteract the
effect of the springs h, which otherwise would ever bring back the moveable
frame to its first position.
Having thus explained the nature of the Invention, and the manner of per-
forming the same, I will explain that what I claim as the parts of the Inven-
tion that I consider belong to me; and, first, in the apparatus described for
the purpose of increasing the combustion of fuel in furnaces or fire-places, I
claim the arrangements represented in the Drawings, particularly the form of
the projecting pieces or fingers of the rake apparatus, by which they readily
enter into the body of the fuel.
Second, in means of working the raking apparatus, whereby the fuel is
stirred and the cinders easily dislodged.
Third, in the means described for preventing the grate from attaining
great a temperature so as to destroy the fire bars.
Fourth, the mode of working the raking apparatus applied to locomotive
engines.
In the apparatus for drying the steam, so as to prevent the water being

page_text: carried into the cylinder, I do not claim surcharging the steam, that having
been done before. But what I claim is, the mode herein described of
regulating the temperature of surcharged steam by mixing it with steam over-
saturated with water. 1 do not claim the arrangement of tubular boilers
shewn, as applied to steam; but what I claim is, the so constructing tubular
boilers that a person may enter into the boiler among the tubes, in order to
clean or repair them. I also claim the mode of constructing the safety valve
with float, and the whistling apparatus herein described. And, lastly, in
respect to the apparatus for regulating the speed of the engine, I claim the
combining with an ordinary governor of a steam engine the apparatus herein
described.
In witness whereof,. I, the said Moses Poole, have hereunto set my hand
and seal, this Eighteenth day of July, in the year of our Lord One