CERTAIN IMPROVEMENTS IN STEAM ENGINES, BOILERS, AND FURNACES, AND IN THE METHODS OF FEEDING AND WORKING THE SAME, AS ALSO IN THE MACHINERY FOR APPLYING STEAM POWER TO PROPELLING PURPOSES
Year: 1842

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HINRIK
ZANDER, of North Street, Sloane Street, in the County of Middlesex, Engineer,
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 Eighth day of November, in the sixth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said Hinrik
Zander, my exors, adññiors, and assigns, Her especial licence, full power, sole
privilege and authority, that I, the said Hinrik Zander, my exors, adñors, and
assigns, and such others as I, the said Hinrik Zander, my exors, adñiors,
and assigns, should at any time agree with, and no others, from time to time and
at all times thereafter during the term of years therein expressed, should and
lawfully might make, use, exercise, and vend, within that part of Her Majesty's
United Kingdom of Great Britain and Ireland called England, Her Dominion
of Wales, and the Town of Berwick-upon-Tweed, my Invention of "CERTAIN
IMPROVEMENTS IN STEAM ENGINES, BOILERS, AND FURNACES, AND IN THE METHODS OF
FEEDING AND WORKING THE SAME, AS ALSO IN THE MACHINERY FOR APPLYING STEAM
POWER TO PROPELLING PURPOSES;" in which said Letters Patent there is contained
a proviso that I, the said Hinrik Zander, shall cause a particular description of
the nature of my said Invention, and the manner in which the same is to be
performed under my hand and seal, to be enrolled in Her Majesty's High Court
of Chancery within six calendar months next and immediately after the date

page_text: 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.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Hinrik Zander, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, are fully described and
ascertained in and by the following Specification thereof, reference being had to
the Sheets of Drawings hereunto annexed, marked A and B, that is to say:-
The improvements constituting my said Invention, which are 10 in number,
as follows:-
The first of my said improvements consists in certain additions to flue boilers
whereby they are enabled to take up more quickly and thoroughly the heat
transmitted from the furnace. I introduce into each flue, whether placed
perpendicularly, or at any degree of inclination from the perpendicular, a thin
slip of iron or other suitable metal, twisted into a spiral form, which by causing
the ascending column of heated air to take a like spiral course, detains it
longer in the flue, brings more of its particles into contact with the metal, and
consequently enables it to part with a greater portion of its heat to the water in
the boiler than if it ascended straight upwards as usual. A flue provided with
this addition is represented in Figure 1, Sheet A. Fis the furnace; B, the
bottom; and C, the top of the boiler; D, the flue passing through it, open at
both ends; E, the passage to the chimney; S, the spiral slip of metal which
is inserted loosely into the flue, or rather is suspended in it, by means of a thin
rod which is passed crosswise through the small orifice a, at top, and rests at the
ends on the adjacent parts of the boiler top. By means of the cross rod, the
spiral slip is also easily lifted out whenever the flue or the slip itself wants
sweeping.
The second of my said improvements consists in certain improved rivets or
fastenings, represented in the sectional views, Figures 2, 3, and 4, of Sheet A,
and applicable to boilers of all descriptions. In Figure 2, G is the side plate
of a boiler, and H, a rivet passed from the inside through the stay I, and
burred up in the usual manner. K is a hollow space, which is bored out of
the exterior end of the rivet after it has been fixed in its place, and constitutes
the peculiarity which distinguishes this rivet from others. Supposing the
pressure of the steam to be raised to near the bursting point, the boiler will of
necessity first give way at the point of least resistance, which is of course in the
hollow space K in the end of the rivet; a bulging out of the plate would then
most probably take place, such as is represented in Figure 3, with fractures in
the direction k, m, and l, m, which would allow the steam to escape through
these fractures without further damage to the boiler. Where screw bolts are

page_text: used, hollow spaces are in like manner to be bored out of the ends of them but
of a smaller diameter than in the case of plain rivets, in order that the threaded
parts may be left of adequate strength. But as it is evident that in proportion
to the total amount of such hollow spaces, the total strength of the boiler
would be weakened, I propose that the rivets should be increased in number in
exactly the same ratio that they are individually reduced in strength. For
example:-Suppose the weight of the metal removed by boring out these
hollow spaces in a dozen rivets should be equal to the weight of four, then
for every dozen rivets that are now made use of sixteen should be employed.
The purpose I have in view, is not to make boilers considered in the aggregate
weaker than they are now ordinarily constructed, but simply to construct them
with such a number of points of least resistance, that in the event of any
excess of pressure tending to explosion occurring, these points of least resist-
ance may serve as so many safety valves to relieve the boiler and prevent
explosion. When a fracture of a plain rivet takes place in any thing like the
manner represented in Figure 3, the boiler may at that part be readily
repaired by removing the ends of the fractured rivet, and introducing from the
outside a screw bolt in the manner represented in Figure 4. The head of the
stay I is to have a female screw tapped in it: a square headed screw bolt L.
with a hollow space K in the head of it, is then to be inserted through the
hole previously occupied by the plain rivet, and screwed into the stay. M is a
washer inserted between the head of the screw bolt L and the boiler plate to
prevent leakage, an object which may be further assisted by any of the ordinary
modes of caulking or cementing.
The third of my said improvements consists in constructing steam engine
furnaces, in the manner and with the additions represented in Figures 4¹ and 5,
Sheet A. Several self-feeding contrivances for such furnaces have been at
different times devised, but none of them have come into general use, owing
chiefly to the length of grating in such furnaces, which renders very com-
plicated arrangements necessary in order to spread the fuel evenly over them.
In the improved furnace represented in the said Figures, the grating is made
proportionally shorter but wider, that is to say, the length is diminished and
the width increased to the extent shewn beyond the proportions usually
observed. A is a revolving feeder, shewn in section in Figure 4¹, and hori-
zontally in Figure 5. It is of the same length as the furnace, and from one to
two or more feet in diameter, according to the furnace area. It consists of an
internal cylinder a, a, and of a number of ribs or partitions radiating from it,
at equal distances from one another, and revolves on an axis i, which is worked
by power obtained from the steam engine, through the medium of the ratchet

page_text: wheel E, and connecting rod F. To charge this feeder, any three of the
chambers formed by the radial partitions which happen to be uppermost, as
for example e, f, g, are filled with coal, and care should be taken so to propor-
tion the capacities of these chambers to the area of the furnace, that when they
are filled they shall contain fuel enough for at least one quarter of an hours
steaming. When rotation is given to the cylinder, as each of the chambers
e, f, g, comes down to the uppermost end of the channel B, the coal drops out,
and passing forward down the inclined plane P, descends upon the surface
grating C. G is a small wicket, by opening which an iron rod may be intro-
duced to stir up or spread the coals in the furnace. The stirring can also be
effected by raising the inclined plane P.
The fourth of my said improvements consists in certain constructions and
arrangements by which engines on the common plan, and with cylinders no
larger than at present, may be worked expansively, to greater advantage than
heretofore. Let A, in Figure 6, Sheet A, represent the stationary cylinder of
such an engine acting on a crank B, through the medium of the beam C and
connecting rod D. To the same crank B, I connect a second cylinder E,
smaller than A, which oscillates freely on its axis, as acted on by the crank B.
The steam is supplied to, cut off, and educted from the oscillating cylinder E in
the same way as to and from the stationary cylinder A, but at such intervals of
time as shall correspond to their relative positions to the crank, so that each
cylinder shall exert its power through a different part of the crank's revolution.
The fifth of my said improvements relates to that class of engines in which
the steam is worked expansively by means of two cylinders, the one smaller
than the other, the steam being first used at a high pressure in the smaller
cylinder, and then conveyed into the larger, where it is allowed to expand
to its utmost useful limit. For this double cylinder arrangement I propose
to substitute the following:-The steam at a high pressure is to be admitted
into a cylinder placed under the crank shaft, and acting on it either
directly by a connecting rod, or indirectly through the medium of a beam and
connecting rod. After the piston has performed a certain portion of its stroke,
the steam is to be cut off, and that in the cylinder left to act expansively to
the end of the stroke. The steam, still far from being exhausted in the air, is
then to be conducted by a pipe, steam room, or chamber to two other cylinders,
larger than the first, in which it is to act altogether expansively. Both these
additional cylinders are to be so placed in respect to the crank, and made to
act in such manner that the three cylinders shall exert their power on the crank
during successive intervals of time, and thus produce one uniform or nearly
uniform motion of the crank. The position of the three cylinders, in respect

page_text: to one another, may be varied according to convenience, but the arrangement
which I consider best, is to place the high pressure cylinder in the middle.
In the Specification of former Letters Patent granted to me, of date the
Seventeenth day of June One thousand eight hundred and thirty-nine, I des-
cribed a mode of transmitting the power to the crank where a second motion
is introduced, which consisted in the employment of a double connecting rod
and I cog wheel, with divided periphery, whereby the cylinders could be placed
in the same perpendicular line athwartships with the shafts of the paddle
wheel and cog wheel. But as it sometimes happens that the paddle shaft
must be placed very low in the vessel, which makes it impossible to have a.
double connecting rod, I propose in such cases to place the cylinder and cog
wheel shaft somewhat in advance, or in the rear of the paddle wheel shaft, but
directly under the cog wheel shaft, so that one connecting rod passing direct
from each cylinder to the cog wheel shaft may suffice.
The sixth of my said improvements consists in a new arrangement of the
double cylinder expansive engine herein-before referred to, whereby it may
with the same cylinder capacity as at present, be worked to much greater
advantage. According to the existing practice, the large or low pressure
cylinder is kept warm by the external application of a body of steam obtained
directly from the boiler; but instead of this, I propose that it should be kept
warm by means of steam drawn from the pipe, steam room, or chamber which
connects the high and low pressure cylinders, after it has done its duty in the
larger or expansion cylinder. At present, a good deal of water unavoidably
collects in the said connecting pipe, steam room, or chamber, consisting partly
of water which comes over from the first or high pressure cylinder, and partly
of that which results from condensation in the pipe itself, which water is
suffered to pass along with the steam into the larger cylinder, whereby the
expansive force of the steam therein is considerably diminished. To prevent
this, I make the connecting pipe, steam room, or chamber, in such double
cylinder expansive engines with a valve in the bottom of it, opening upwards,
from the bottom of which there rises a spindle with a float at top, so that when
water accumulates in sufficient quantity to raise the float, the valve is raised
with it, and the water allowed to escape.
The seventh of my said improvements consists in an arrangement for
lessening the pressure of the steam on the slide valves of steam engines. A, in
the sectional view Figure 7, represents the steam port to the cylinder; B, the
induction steam pipe from the boiler; C, a slide valve, consisting of a frame
of the square form separately shown in Figure 8, to the face of which is
attached a thin metal plate a (which plate may be doubled where there is any

page_text: unusual pressure to be sustained; D is the rod by which the slide valve C is
moved; E is a second or relief frame attached to the front plate a, which is
provided with four wheels or rollers F, F, F, F, (two of which only are seen
in the Drawing) which rest on the cylinder A; K, the part of the second
frame E which is fastened to and presses immediately on the plate a of the
other frame, and is of considerably less area. As the slide valve C is moved,
the additional frame E follows in the same direction, moving more or less
from C, according to the motion of the wheel. For supposing the steam in
the cylinder A to have been expanded by the condenser, the pressure of the
steam in the induction chamber B on the valve C will be diminished exactly
to the same extent that the area of the front plate a is covered by the part K
of the frame E. Thus if the pressure of the steam be equal to twenty pounds
on the square inch, and if the area of the valve C be forty square inches, then
the load or pressure due to that area would be eight hundred pounds; but if
we suppose the area of the part K of the relief frame E to be thirty square
inches, then there must be six hundred pounds of that load transferred to E, or
rather through E to the cylinder on which, by means of its four rollers, it rests,
thus reducing by three-fourths the immediate pressure on the valve C. When,
instead of the single plate a, two or more sets of plates are introduced between
the valve C and the relief frame E, they should be so arranged that each set
of plates should have its own separate and independant motion; for example,
two sets of plates may be combined, as represented in Figure 9, Sheet A, the
one being fixed to the valve frame C, and the other to the relief frame E.
When the steam is to be worked expansively, an expansion valve may be added
in the manner represented in Figure 10. The set of plates H is to be attached
to a strong plate M resting on four columns L, L, (two of which are seen in
the Drawing,) fixed in the valve frame C; and in order that the space between
the set of plates H may have a free communication with the inside of the
valve C, channels are to be cut through one or two of the chambers, as repre-
sented at 2, 2. The expansion valve, with its appendages, is to be introduced
between the plate M and the valve frame C. If the distance between the
valve and relief frames is great, instead of wheels or rollers being used, by
which to rest the relief frame on the cylinder, rollers consisting of the. segments
of a circle only may be employed.
The eighth of my said improvements consists of a new arrangement of
working engines expansively, represented in the sectional view, Figure 11,
Sheet A. A is the valve box; B, a slide valve of the common D construction,
with a conical passage C, which on the side next to the induction port G has
one opening a, b, of the same area as that port, while on the opposite end

page_text: it has three apertures d, e, f, the united areas of which are equal to the single
opening a, b; D is the expansion plate (made just of sufficient thickness as to
work without bending), in which there are three apertures g, h, i, corresponding
in size to the apertures d, e, f. The faces of the valve B and expansion
plate D must be ground so truly that when pressed against each other they
shall be steam-tight. E is an outer frame, between which the expansion
plate D moves, being attached by means of the connecting bar t, t, to the
valve B, and carrying on the face of it two springs F (one of which only is
seen in the Drawing), which, pressing on the latter, keep it always in its
proper position; for example, when the slide valve B has performed one-half
of its stroke, as represented in Figure 11, the expansion plate D should then
just commence closing the aperture d, e, f, and thereby cutting off the steam
collected in the box A from the cylinder G; and to insure this, there is a stop
H as long as the expansion plate D is broad, which catches and stops the
plate exactly at that half point of the stroke, while the valve B, continuing its
progress, has its apertures d, e, f, closed by the solid parts l, m, n, of the plate
D. The valve B, having now completed its down stroke, will commence
returning to the top of the valve box in order to cover the induction port and
open the eduction passage, and as the expansion plate D is kept by the springs
F, F, acting on all sides fast to the outer frame E, and that frame E is made
fast to the valve B, the plate D follows the valve B in its ascent (keeping, in
the meanwhile, the apertures d, e, f, closed) till it strikes against the stop I
fixed at the top of the valve box, and stopped by it, while the valve B continues
in the upward direction, brings its apertures d, e, f, in the same place with the
apertures g, h, i, of the plate D, when new steam is admitted, and a new
stroke commences. As it may be desirable to have the power of cutting off
the steam sooner or later than would be practicable were the stop H a fixture,
the following additional arrangements for this purpose have been made. A
bolt K with a spiral groove p is inserted into the stop H. A vertical rod L,
the lower end of which N turns in a fixed socket O, and the upper end of
which is carried through the top of the valve box A, has a projecting pin
which takes into the spiral groove of the bolt K, so that as this rod is turned
to the right or left, the stop H will be raised or lowered, and the cutting off of
M is a handle to the
the steam be made proportionally sooner or later.
vertical rod L, by which it may be turned by hand to any extent desired.
Where a double slide valve is employed, the arrangements are the same as for
a single valve, with the exception that the spiral groove is made in the opposite
direction, in order that one rod L may move both stops. To lessen the push
of the plate D against the stops H and I, springs are attached to the faces of

page_text: the latter (but not seen in the Drawings). In the case of very large engines,
where it may be apprehended that the springs F, F, will not be sufficient to
keep the expansion plate D in its proper position, it may be further expedient
to have a rod carried up from the plate D through the top of the valve box, by
means of which it may be occasionally adjusted to its proper bearings.
'The ninth of my said improvements consists in the apparatus represented in
Figures 12, 13, 14, 15, and 16, Sheet A, for condensing, by means of metal
surfaces, the exhausted steam after it has done its duty in the cylinders of
marine engines, the same being in part similar to the condensing apparatus
formerly invented by me, and included in the before-recited Specification of
Letters Patent of the 17 day of June 1839, and in part an improvement
thereon. Fig. 12 is an end view; and Fig. 13 a side view of this apparatus.
A is an air-tight cistern of wrought or cast iron, in which are fixed in an
upright position, a number of copper vessels B, B, B, of a parallelopipedal
form, which are open at top, and communicate at bottom with a pipe E, and
are surrounded with cold water to the height of the line C, or about nine
inches from the top. The exhausted steam is conveyed into this cistern from
the cylinders through the exhaustion pipe D, and as it comes in contact with
the vessels B, B, B, becomes condensed, and falling to the bottom thereof in
the form of water, passes off (mixed with a good deal of air through the
inclined pipe E, into a receiving pipe F, and thence by the connecting pipe G,
to the air pump H. The condenser just described having no pressure to
sustain, the vessels B, B, may be made of very thin copper, averaging nct more
than about one pound weight per square foot, and as the thinner they are the
greater is their cooling property, it follows that a lesser extent of surface will
suffice to condense a given quantity of steam than where a condenser is cm-
ployed, which is subjected to considerable pressure, and has its vessels made of
a corresponding thickness. To prevent the vessels B, B, from collapsing by
the pressure of the water outside of them, and also to encrease the amount of
cooling surface, I insert in each vessel zig-zag slips of copper, such as are
described by me in the before-recited Specification. And to support still
further these vessels, as well as the cistern A itself, against the external
pressure of the atmosphere, I insert one or more rows of stays, as represented
at I, Figs. 12 & 13. These stays consist of loose pieces of copper or iron
inserted crosswise between the vessels B, B, B, or in the the case of the outer
vessels between them and the sides of the cisterns; and to keep them all in
one line, a vertical iron wire is affixed to each, which passing to the top and
bottom of the cistern is there hooked on to a horizontal rod, common to the
whole. (To avoid confusion, these wires and the horizontal rod common to

page_text: them are omitted in the Drawings. In the case of very large condensers there
may be similar regulating iron wires carried out from the stays to the sides of
the cistern as well as to the top. Should any one of a series of such con-
densing cisterns become leaky, it can, by simply unscrewing the nut, be removed
for the purpose of repair, without interfering with the rest. The number and
size of the condensing cisterns employed, will of course depend on the quan-
tity of steam required to be condensed in any given time. I find by experience
that for each cubic foot of water converted into steam in an hour, the amount
of condensing surface requisite varies from five to ten square feet according to
the thickness of the metal. The cold water required for the purpose of the
apparatus is supplied from the outside of the vessel by means of the pump K,
which is connected with and worked by the engine in the usual way. Thus,
suppose the slide valve a to be opened and the piston L to descend, water will
rush in through the pipe M, and fill the pump, while on the return or up
stroke of the piston the valve a will become closed, and the valve b on the
opposite side opened, when the water raised by the piston will be discharged
through the open valve b into the pipe N, down which it will pass into the
bottom of the cistern A. As the water then rises in the cistern among the
vessels B, B, it takes more or less of the heat of the steam collected in the
vessels, and when it reaches the line C it flows over into the pipe O, and
passes therefrom into the bottom of the pump, whence it it is ejected in a
warm state through the pipe P back into the sea or other water outside. The
valves at the top of the pump for the admission of the cold water and its
transmission to the cistern, should be slide valves, such as are represented in
Figure 12; but common clack valves, such as are also shewn, will suffice for
the orifices at bottom, through which the water passes away after having gone
the round of the cistern. To prevent the water from ever exceeding, through
any accidental obstruction, the height of the line C by more than an inch or
two, there is a float Q provided, which as soon as the water reaches it, rises
and opens a small valve R in the top of the cistern, which admitting the
external atmosphere, thereby stops the further ascent of the water.
But as
this arrangement may be attended in some cases with inconvenience, a slide
valve or throttle valve, worked also by a float to serve the same purpose, may
be placed at S, being so combined as to shut more or less the mouth of the
supply pipe N, according to the rise of the water in the cistern. In this case,
however, the valves a and b at the top of the pump must be so adjusted that
in the event of the pipe N being completely closed at bottom, they shall yield
to the back pressure and open outwards. As the water, when it returns from
the condenser, is considerably encreased in volume by the heat which it has

page_text: As in this case there is no
absorbed, the piston rod T of the pump is made considerably thicker than is requi-
site for strength, merely in order that the area above the piston may be dimi-
nished in proportion to the difference between the volumes of water above and
below it. In the arrangements for condensation which I have thus described,
I have assumed that there are three pumps to be employed, one (K) for
supplying the condenser with cold water; a second (H) for pumping the water
and air resulting from the condensation; and a third (not shewn in the Draw-
ings) for feeding the boiler with the water furnished by the second; and I find
in practice, that less power is required from the engine to work the three pumps
conjointly in this manner than is necessary when the two last only are as usual
employed. But where such a saving of power is of no consequence, or where it is
desired to apply my condensing system only to an engine already built with an
air pump on the ordinary plan, then the arrangement should be varied in the
manner shewn in Figures 14, 15, and 16, Sheet A; Figure 14, being an end view;
Figure 15, a side view; and Figure 16, a plan. (The letters in these Figures
indicate the same parts as in Figures 12 and 13).
separate cold water supply pump, the cistern A is supplied with water from the
outside of the vessel by means of a common injection pipe T, but without any
rose attached to it. The water rises, as before explained, among the condensing
vessels B, B, till it reaches the line C, when it flows over through the orifice V,
into the right angled pipe U, which leads to the common air pump W. But in
order that the air pump W
may not draw off steam as well as water from the
condensing cisterns, the following checks are provided. At the bottom of the
pipe U there is placed a hollow float, which is open at top for the reception of
water, but closed and of a conical shape at bottom. At top this float is con-
nected by the vertical spindle e to one end of a horizontal beam f, which turns
on a fulcrum g, fixed to the top of the pipe U (inside), while to the opposite
end of the beam f, a counterpoise h is attached of such weight that when the
pipe U is employed, the float X, with its fill of water, shall overweigh it, and
drop into the conical seat i made for it in the cross plate k. Supposing the
float to be in the position just described, and that water then flows over from
the condensing cistern A into the pipe U, it will accumulate at the bottom of
the pipe till it rises to about the line l, m, near to the top of the float, which
losing thereby the weight which it possessed when suspended in air, only becomes
overbalanced by the counterpoise h at the opposite end of the beam f, and
being raised from its seat allows the water to flow through the now open aper-
ture to the air pump W. As soon as the pipe U is emptied, the float falls down
again, and closes up the aperture as before. Through this channel, there-
fore, it is obvious that nothing but water can find its way from the upper part

page_text: of the condensing cistern A, into the air pump. The steam mixed with air
which comes from the cylinders into the cistern A by the exhaustion pipe D,
parts with the air it contains in the course of condensation, and the air with
the water of condensation then pass off together into the chamber G. To the
bottom of this chamber there is a small pipe n attached, through which the
water is conveyed to the feed pump Y, while the lighter air escapes from the
top of the chamber through the curved vertical tube Z. To prevent this
tube Z from acting as a syphon, in which case it might draw over some portion
of the water of condensation along with the air, it is raised a good deal higher
than the water line C of the condensing cistern A, and at the point of curva-
ture q is made much wider than in any other part. The descending limb of the
tube terminates in a chamber o, whence the air passes through the orifices p, p,
to the air pump W, the orifices p, p, being opened and shut by common clack
valves acted on by the pressure of the air.
Should it be desirable at any time, either from the wearing out of the parts of
this condensing apparatus, or from any accidental damage, to have recourse to
the old method of condensation, this can readily be effected by making the fol-
lowing changes in the preceding arrangements which may be accomplished in
a few minutes, and even without stopping the engines for the purpose. Let
the cock of the injection pipe T be closed, and the cock of the pipe A² be
opened. The water will pass through the pipe A", from the outside of the
vessel into the interior pipe B2, which is perforated with small holes so that the
water may flow out from it in a number of small jets, and condense the steam
collected beneath, exactly after the manner of the common condenser. A
valve G2, which is interposed between the chambers G and o, and under all
other circumstances is kept constantly closed, must also be opened in order to
allow both the water and air which come from the condenser to pass freely to
the air pump; and finally, in order that the air may also pass freely through
the pipe U and aperture i, to the air pump, the action of the beam f must be
suspended by screwing down upon the weighted end of it the screw S². Of
course it will be necessary that the apparatus should be previously provided
with the additional parts A2, B2, G2, and S2, last herein-before described.
The tenth and last of my said improvements consists of an improved paddle
wheel for steam vessels. In order that the principle followed out in the con-
struction of the paddle wheel and the difference between it and all other wheels
heretofore constructed may be clearly understood, it will be proper to enquire,
in the first place, what is the dynamical effect (theoretically considered) which
a float board or paddle produces in its passage through the water. It has been
experimentally ascertained that the action of a plain surface moved through a

page_text: fluid is always perpendicular to such surface in whatever direction the motion
may take place. Keeping this principle in view, let Figure 1, Sheet B, be
supposed to represent the half of a paddle wheel so far immersed in the water
that the centre of the axis G is on a level with the water line E, A, B, F.
When the wheel is put in motion the paddle E, A, is forced vertically down-
wards with more or less velocity, and as long as it moves in this vertical direc-
tion only, without any horizontal inclination, the only tendency it has is to
heave up the vessel and retard the revolution of the wheel. When it arrives
at the point marked 1, it then acts on the water in a direction which will be
represented by the diagonal line a, b; for according to a well known mechanical
maxim, if two forces be represented in quantity and direction by the sides of a
parallelogram, a force equivalent to the two will be represented by a diagonal
line drawn from corner to corner; in other words, the action of the paddle at
the point 1 is equal to the joint action of two forces in the direction of the
sides of a parallelogram, of which the one a, c, has a vertical action, and the
other a, d, a horizontal action, the horizontal action being that alone which
tends to propel the vessel, while the vertical action, as before explained,
serves only to obstruct it. If, therefore, we suppose the power communicated
from the steam engine to the paddle E, A, and exerted through the space E 1,
to be equal to 24 dynamic units, and that it is expended on the vertical and
horizontal forces in the same relative proportions which the lines a, c, and c, d,
bear to each other, then 3.2 dynamic units will be the amount of the power
expended on the horizontal or propulsive force, and 20.8 the amount wasted
on the vertical obstructive force. As the paddle proceeds in its circular course
through the different points marked 1, 2, 3, 4, 5, 6, 7, 8, 9, the horizontal
force exerted continues gradually to increase, and the vertical one to diminish in
the proportions denoted by the series of parallelograms a, d, b, c, and the
numerals affixed thereto in the Drawing, till, on passing the central or perpen-
dicular line G, C, the vertical line vanishes altogether, and at C the whole
power of the paddle, equal to the 24 dynamical units, is employed in the hori-
zontal propulsion of the vessel. As the paddle re-ascends on the opposite side
of the wheel through the points 10 to 19, the force becomes once more com-
pounded of a horizontal action and vertical action, but with this difference,
that the horizontal action continues gradually to diminish and the vertical to
increase in the proportions shewn in the Drawing, till at the point 19 the
former is reduced to zero and the latter absorbs the entire power of the 24
dynamical units, and with this further difference, that instead of the vertical
action tending to depress the water and heave up the vessel, it tends on this
side of the wheel to raise the water and depress the vessel. If from the

page_text: central point G, we draw with a radius G, A, a semicircle A, C, B, it will be
found to pass through all the points a of the series of the parallelograms, which
represent the variations in the horizontal and vertical forces, and that it con-
sequently includes within it the whole of the lines a, d, on the one side of the
vertical line G, C, or their equivalents c, b, on the other side, which represent
the horizontal forces, while the whole of the lines a, c, and b, d, which repre-
sent the vertical forces, are left on the outside of that curve. If, farther, we
draw from the centre point G a number of radial lines through the points a, a,
of the series of parallelograms to the outer points E, 1, 2, 3, 4, &c., and make
the distance of each of the points E, 1, 2, 3, 4, &c., from the semicircle
A, C, B, equal to the length of the side a, c, or b, d, of the next adjoining
parallelogram, (which side represents the vertical force) and draw a curve
E, C, F, through the points E, 1, 2, 3, 4, &c. so obtained, then will the space
between that curve and the semicircle A, C, B, represent approximatively the
amount of the vertical forces exerted. If we draw another curve A, D, B,
through a series of points e, f, g, &c. to z, the distance of each of which from
the semicircle A, C, B, is determined in like manner as in the preceding case
by the length of the line a, d, of the next adjoining parallelogram (which
represents the horizontal force exerted, and if the two spaces are then
colored, the one red and the other blue, the difference of magnitude between
the two spaces at each point of the semi-revolution of the wheel will be made
at once perceptible to the eye. I do not mean to say that the Figure repre-
sents with perfect correctness the actual state of things throughout the entire
semi-revolution of the wheel, for it is well known that in practice the resistance
to a plain surface moving in a fluid does not always correspond with the mathe-
matical theorem, that it is in proportion to the square of the sine of the angle
which the direction of that surface makes with the line of direction, and also
that the velocity of a paddle at its lowest vertical position is less than it is in
other positions. But these and other necessary corrections notwithstanding, I
consider that the figure approximates sufficiently to the truth to give a correct
general idea of the existing system of propelling steam vessels, and of the
defects in it which required to be remedied.
The elements of the improved mode of propulsion which I propose to adopt
are exhibited in the diagram Figure 2, Sheet B. Let K, L, represent a line
passing through the centre of a paddle wheel; II, I, the water line; and 16 an
arm of the wheel, with a common paddle b, a, affixed to it. On motion being
given to the wheel, the arm 1 b, will pass from 1 to 15 on the line K, L, and the
paddle b, a, attached to it will pass at the same time through the various positions
shewn in the Figure till it assumes that represented by the line c, d, 15. In

page_text: passing from b, a, to c, d, the paddle will, therefore, have disturbed or put in motion
the water between the curved lines b, e, d, and a, f, c, and the propelling and lifting
force exerted in doing so will be represented by the space between a, b, and e, f,
and the propelling and depressing force by the space between e, f, and d, c. It
follows that as the two spaces are equal the opposite forces must also be equal, and
that as they balance each other, neither can, in the state of things here supposed,
be of any use in propelling the vessel; but instead of the paddle board being in
one piece let it be divided into several parts-say, for example, into four parts,
and let them be so fixed in respect to each other that a line h, g, making an angle
of about 37 degrees with the radial line h, o, of the wheel shall pass through the
centre of the four parts. Then as the radial line h, o, passes from 0 to 14 in the
line K, L, the four paddles will assume the various positions shewn in the
Figure till they exhibit that represented by the line i, k; the water disturbed
or put in motion in the passage from h, g, to i, k, will be that included within
the curved lines g, l, k, and h. f, i, and the space between h, g, and the vertical
line e, f, will represent the amount of the propelling and lifting force exerted,
and the space beyond, between e, f, and i, k, the amount of the propelling and
depressing force exerted. Now it will be at once seen, on inspection of the
Figure, that of the two spaces the former is much larger than the latter, and
that consequently there must be a proportional balance of effect in favour of
the propelling force, and as this advantage is not obtained by any increase of
surface for the areas of the four paddles are exactly the same as the area of
the single paddle-it follows that it must be the effect entirely of the sub-
division and better distribution of that surface. It is further important to
observe, that as the adoption of smaller paddles placed in the manner shewn in
the Figure will admit of a much greater number being introduced into a wheel
than would result from simply dividing any number of large single paddles
into sets of four or more smaller ones, the total paddle surface may be thus
also considerably augmented. On the principle which I have thus demon-
strated I have constructed the improved paddle wheel, a half view of which is
represented in Figures 3 and 4, Sheet B; Figure 3 being a side view, and
Figure 4 an end view. A is a horizontal line passing through the centre of
the wheel; C, C, are the arms; D, D, the rings or circles between which the
paddles e, e, are fixed on suitable bearings, and in such positions in regard
to one another that a straight line drawn through their centres as f, g,
makes an angle with the vertical line h, d, of 37 degrees; the surface of each
paddle e besides, being in nearly a line with the central point h of the
wheel. The paddles are placed at such distances apart that the line f, g, which
passes through the centres shall be about equal in length to the distance

page_text: between the water line b, and the outer ring D. Although in the wheel just
lescribed, cach set of paddles is four in number, I do not limit myself to
hat or to any particular number, for the number may be varied at pleasure.
In Figure 5, Sheet B, I have exhibited part of a wheel with only two floats.
A, and B, are two arms of the wheel; C, the inner ring, and D, the outer.
E, E, are shorter arms attached to the rings C and D. F, F, are the sets of
paddles, some being attached to the long arms, and others to the short arms;
but each pair or set are placed in such relative positions that a straight line
a, b, passing through their centres makes an angle of about 37 degrees with
the radius line c, d. The angle of 37 degrees has been adopted in the two
wheels last herein-before described, because it is that which approaches most
nearly to the angle which a series of floats take, when they rise out of the
water in nearly the same spot, (supposing the wheel to be stationary,) and it
may be therefore supposed to be the angle of least increasing resistance. But
there may be circumstances which will render it advisable to give to the line
which passes through the centres of the sets of floats, a greater or less degree
of inclination than 37 degrees. For example, when the wheel is required to
be deeply immersed, it is then of advantage to increase the area of the floats and
to place them at a greater distance apart, so that the paddles may have the most
work to perform when they are in a vertical position. Then, suppose one of
the arms or paddles E, F, in Figure 4, Sheet B, were for the above purpose
moved forward to G, K, then a straight line f, e, passing from the centre of the
surface of F, at n, through the centre of K, would form an angle of about
52 degrees with the radius line d, f; and the next paddle in advance L, ought
to be at such a distance that another straight line e, g, carried from the centre
of G, K, to the centre of L, should be of the same length as f, e, and form with
the radius of the wheel a like angle of 52 degrees. But still for general
purposes, the angle of 37 degrees is that which I esteem the best, and in
no case should I think it advisable to make it less than 30 degrees, or more
than 56. It will be understood, that in all cases the motion of the wheel
when going headways must be in the direction of the arrows, as represented in
the Drawings, Figures 2, 3, and 4, from H to I, as shown in Figure 5. The
paddles may be of any suitable material; but where they are in sets of three
or four, or any greater number, I consider it best to make them of iron plate,
and when in sets of two, to make them of wood. And now, to sum up the
peculiar features and advantages which distinguish my improvements from
others, I consider them to be these:-First, instead of using a few large
paddles, I employ a number of smaller paddles, presenting an equal or greater
extent of resisting surface. Second, I place these smaller paddles in such

page_text: relative position that a straight line shall pass through the centres of each se
of two, three, four, or more, at an angle of from thirty to fifty-six degrees, by
which means they are all made to enter the water at separate points, and con-
tinue to describe separate patlis, till they pass the centre line of the wheel
after which the paths described by them approximate so rapidly, that the
paddles emerge from the water in nearly the same spot, whereby the amount
of horizontally propelling force obtained before passing the centre is much
greater than usual, and the amount of the prejudicial resistance afterwards is
considerably diminished, while at the same time the paddles perform their
revolutions with much greater steadiness and smoothness. And, third, the wheel
is divided into two, three, or more parts, in the direction of planes parallel
with the framing of the wheel, an arrangement which contributes still further
to the steadiness and smoothness of action.
And having now described the nature of the several improvements included
in my said Invention, and the manner in which the same are to be performed,
I declare that what I claim as regards each of them is as follows:-First,
I claim the use of twisted slips of metal inserted in the flues of flue boilers in
the manner before described, for the purpose of accelerating the generation of
the steam. Second, I claim the improved mode of fastening or rivetting
boilers of all descriptions, as before described. Third, I claim the mode of
feeding furnaces when used in combination with the improved arrangement of
furnace, both before described. Fourth, I claim the employment in manner
before described, of a second or oscillating cylinder in the case of steam engines
of tho ordinary construction when worked expansively. Fifth, I claim the
three-cylinder arrangement before described, proposed to be substituted for the
present double cylinder expansion engine, and the mode of emptying the water
from the chamber between the cylinders; as also the before described combi-
nation for the purpose of engines worked expansively of two cylinders applied
to one crank shaft, a connecting rod passing direct from the cylinder to the
cog wheel shaft, and a cog wheel with divided peripheries; but disclaiming the
use of any of those three things separately. Sixth, I claim the mode before
described, of working double expansion steam engines whereby the larger or
expansion cylinder is kept warm by steam supplied from the pipe, chamber, or
steam room which connects the two cylinders, instead of direct from the boiler
as usual. Seventh, I claim the employment of relief frames, in manner
before described, to lessen the pressure on the valves of steam engines.
Eighth, I claim the improved valve arrangement for working steam engines
expansively, before described, in the general combination of parts of which it
consists. Ninth, I claim the improved surface condensing apparatus before