CERTAIN IMPROVEMENTS IN CONSTRUCTING AND PROPELLING VESSELS, AND IN THE MACHINERY CONNECTED THERE- WITH
Year: 1845

page_text: OXLEY'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
OXLEY, of Westminster Road, in the County of Surrey, Civil Engineer, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-second day of August, in the ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Thomas Oxley, my exors, adñiors, and assigns, Her especial license, full
power, sole privilege and authority, that I, the said Thomas Oxley, my
exors, adñiors, and assigns, or such others as I, the said Thomas Oxley, 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 herein expressed,
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
CONSTRUCTING AND PROPELLING VESSELS, AND IN THE MACHINERY CONNECTED THERE-
WITH;" in which said Letters Patent is contained a proviso that I, the said
Thomas Oxley, shall cause a particular description of the nature of my 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
Thomas Oxley, hereby declare that the nature of the said Invention, and
the manner in which the different improvements of which the same consist
is carried into effect, are fully described in and by the present Sepcification
thereof, reference being had to the Drawings hereunto annexed, that is to
say:-
The first branch of the said improvements has relation to the class of
submarine or submerged propellers called screw propellers, and consists in so
constructing them that the area of resistance may be expanded or contracted
at pleasure, according as circumstances may require. I make each segment
or blade of two or more pieces or parts of suitable metal, one of which parts
or pieces is made fast upon the propeller shaft or axis, and called the back
piece (no matter whether it be placed to face towards the rudder or towards
the fore part of the vessel), and the other piece or pieces is or are adjusted
to move backwards, forwards, or sideways upon the said back piece, and is or
are called the front blade or blades. There may be either one, two, three, or
more of these front or shifting blades attached to one back piece, and they
may be actuated so as to increase the resisting area in breadth only, or both
in length and in breadth.
In Figure 1 of the Drawings hereunto annexed I have given a plan in
section of an expanding screw propeller on the above principle. A, B, C, D,
is the propeller shaft, which it is necessary for the purposes of this part of my
Invention to make hollow, which shaft carries the propelling blades or seg-
ments P, P, of which f, f, are the back or fixed pieces before spoken of, and
8, 8, the front or shifting blades. J, J, is a solid shaft fixed inside of the
hollow shaft A, B, C, D, by means of which the shifting blades are actuated
in manner to be next explained. On the inner end of the shaft J there is
fixed a bevil wheel F¹ (Figure 1), into which a smaller wheel or pinion (E)
works, which is turned by a winch or handle Y; these wheels F and E being
enclosed in a drum or box L, L, through the top of which the handle of the
winch Y is passed. On the outer end of the same shaft J there is fixed a
bevil wheel W (Figure 1,) which actuates two pinions p, p, which work two
endless screws e, e. Each of these screws (e, e,) is borne at the outlet end by
an upright bearing F, and passes through a female threaded screw U. Front
views of F and U are given separately in Figure 1 and Figure 1. The
uprights F are attached to the fixed pieces f, f, of the propeller blades, and
their shanks pass through slots or long openings made in the sliding pieces
s, 8, and are fixed to the back pieces f, f. On turning the shaft J, by means
of the winch Y and the wheels E and F, the revolution of that shaft operat-

page_text: ing on the shifting blades s, s, through the medium of the wheels W, the
pinions p and screw e causes them to expand or contract according to the
direction in which the winch is turned. Instead of giving motion to the
expanding pieces of the blades by the means just described, the following
arrangement may be adopted:-Let a pulley, having strong projecting points
of metal on its periphery, be fixed in the same place as the wheel W, and
another similar pulley at the end marked F; then, over these two pulleys let
an endless chain be carried, through which an upright of a U shape is passed,
attached to the front or shifting blades s, s; on the inner shaft J being turned,
this chain would be put in motion, the teeth of the pulleys would take into
the links of the chain, and the sliding blades 8, s, be made to move backwards
and forwards as required.
In Figure 3, 4, 5, 6, I have exhibited a double-expanding propeller on
the same principle as the preceeding. Figure 3 is a view of the back
piece; 9, g, is groove formed by two strong side pieces of metal n, n, and
in this groove slides the guide piece or slider D, D, (Figure 6). Figures
4 and 5 represent the shifting or expanding blades; to the front of these
blades, Figure 4, a strong piece of metal a, b, which I call the guard piece,
is attached at a, x; and from x to b sufficient space is left between the guard
piece and the blade to let the back piece, Figure 3, pass freely between them.
I place the blade, Figure 4, immediately next to or before the back piece,
Figure 3; and then next to Figure 4 I place the other shifting blade,
Figure 5, which has a guard piece c, d, similar to a, b, which allows the pieces,
Figures 3 and 4, to pass between it and the blade (Figure 5) to which it is
attached. A bolt P, Figure 3, which serves as a common pivot or centre
of motion, is passed through the holes P2, P3, of the blades, Figures 4 and 5,
which turn upon it, and by having a broad head it holds them securely in
their position. Upon this slide D, D, there is fixed a V shaped piece of
metal, having a long slot or opening w, x, in q, through which two strong
bolts e, e, with flat heads, are passed, and firmly fixed to the sliding blades,
Figures 4 and 5. When the sliding piece D, D, is moved backwards or
forwards, its action on the bolts e, e, causes the blades (Figure 4 and 5) to
which they are attached to be protrodued or drawn in.
Figure 7 represents a modification of the expanding propeller last described P.
b, c, is the back piece as before. The dotted lines b, y, and c, x, indicate the
lines which divide the front or sliding blades B1, B2, down the middle of each;
he blade B¹ has a leg or limb h, f, coming out sideways, being a few degrees
n an angle to the line b, y; and in like manner the blade B has a short
imb q, e, projecting from it in the opposite direction; the pivot on which

page_text: these expanding blades turn is at n. T, T, is a V piece with slots, as before
described, which is made fast by bolts or pins with broad heads to the legs
h, f, and q, e; or, instead of this, the legs h, f, and q, e, may have slots in
them, and the bolts or pins be attached to the piece T, T; in either case the
expansion of the blades B', B, is produced by pushing the slide P, S, back-
wards and forwards. The motion to the slides may be given by any of the
means herein-before described, or by a wheel and rack as exhibited in
Figures 6, 8, 11, and 12. A single expanding propeller on this plan may be
made by using one slideing piece, and the back or fixed piece only.
Two triple expanding propellers are represented in Figures 8 and 11. Each
of these has a lid or cover, and the expanding blades are shut up therein like a
sword in its scabbard. Figure 8 has a back piece, which is separately represented
in Figures 9; a, b, is a groove in which a dovetailed slider works, to which
slider is firmly attached a central segment d, g, d, m, m, (see Figure 8);
9, 9, 7, 9, (Figure 8 and 9) are two other grooves inclined sideways from the
central line of the propeller, in which work feather-edged sliders, to which
the segments a, a, e, e, and b, b, c, c, Figure 8, are respectively attached. The
dotted lines b, d, n, and a, d, n, shew that portion of the central segment
which is covered by the two other segments; h, l, is part of the groove in
which the central slider works; this groove extends from 1 to K, and the slider
itself extends the whole length of the central segment from m to g. R, R, are
two short connecting rods; a pivot fastened to the central segment passes
through each connecting rod at the inner end m; at the outer ends of the
connecting rods there are slots to receive the corner parts of the segments B
and B2, which move respectively upon pivots at n, n; when by the motion of
the rack the central segment is moved backwards and forwards, the two side
segments B', B², arc by means of the connecting rods carried smoothly along
their sliding pieces, keeping always in the grooves q, q, which preserves them
in a parallel position to the central segment, and also to each other. (A similar
arrangement to this might be usefully applied to produce parallel movements
in the steam engine.)
Figure 10 is a section of the back and cover of the propellers (Figures
8 and 11).
c, c, is the cover, and q, a, q, the back piece; and here a
shews the groove for the middle slider, and 9, q, the grooves in which the
side slides work. The dotted lincs m, m, shew how the back increases in
thickness up to the shoulder part by which it is fastened upon the propeller
shaft. The propeller blades may be attached in various ways to the shaft,
but the mode which I consider the best is, to have parallel flanges upon the
shaft, as shewn in Figure 22, where C, D, represents a part of the cylindrical

page_text: propeller shaft, a, b, one flange, and c, d, the other, each having holes in it for
bolts or screws. These flanges may be made all the way round the shafts,
or only a part of the way. It will also add to the security of the propeller to
have flanges extending lengthways on the shaft, as from a to c, and from 6 to d,
making the shoulder end of the propeller to correspond exactly therewith;
this will be found very useful in carrying out the plan of repairing submarine
propellers and putting on new ones when a vessel is out at sea, as herein-after
explained.
part of the
In Figure 11 four blades are shewn in their expanded state, each being
on the triple plan which has been just described; m, m, is a thin broad
metal bar, which is made fast upon the other two segments d, d, g, g, and
x, x, y, y. At the end of the bar near S enough of the metal is cut away to
let the bar m, m, work freely backwards and forwards; 1, k, is
cover cut away to let the end of the rack r, r, pass freely backwards and for-
wards when acted upon by the wheel W inside of the propeller shaft. I
consider this to be a great improvement upon the plan of propeller Figure 8,
because the cross bar m, m, will keep much longer in good working condition, in
putting in motion the two side segments, than would the pivots and connect-
ing rods in Figure No. 8. The arcs marked u, e, shew the magnitude of the
propellers in their unexpanded state.
Here
Figure 12 represents a longitudinal plan of a propeller shaft, with the pro-
peller blades fixed upon it in the manner that I most approve of. P, P, is the
stern post. I may here observe, however, that I propose using two of these
screws on board each vessel, more particularly if the vessel be a large one, and
in that case there must be two additional stern posts, one to the right and the
other to the left of the common stern post. W, W, is the wall of the bulk
head on that part of it nearest the stern, and g, g, is a stuffing box and bearings
through which the shaft works. A, B, C, L, L, is the drum before mentioned
as enclosing the wheel gearing by which the interior shaft J is worked.
the propeller slides 1 and 2 are shewn edgwise. No. 1 shews the back edge, or
is on that side of the shaft opposite the spectator. No. 2 is on that side next
to the spectator, and displays the central end, the two side segments each in its
expanded state. The segment 3 is on the lower side of the shaft, and the
spectator sees what may be called the front or cover side of it. The part cut
away in the shaft for the rack of the segment 3 to be in contact with the wheel
inside the shaft is on that side of the shaft opposite to the spectator. The
blade 4 is shewn with its back to the spectator, and here the part cut away for
the rack is on that side the shaft nearest to the spectator. All these openings
in the shaft are at a considerable distance from each other, and leave the

page_text: shaft sufficiently strong for its duty, which would not be the case if the
four blades were all placed in the same plane of rotation. I determine the
distance in manner following:-From the point N of the blade 2 I let fall a
perpendicular, N, R, and N, S, being the chord line of the blade (which is here
supposed to be equal to six feet). I call N, S, the radius, which gives 2.05
feet for the natural sine of the distance required, the blade being set to an angle
of twenty degrees with the plane of rotation. The blades being fixed on in this
manner causes each blade to act upon a separate stratum of water, and though
the blades may extend over a large arc of the circle the waterway can never
be choked. My experiments lead me to believe that a propeller, with the
blades arranged in this manner, will possess a much greater power of propul-
sion than any other form or kind of screw propeller where all the blades are
huddled together on one part of the shaft, and are all placed in the same plane
of rotation. Should it nevertheless be desired to have all the four blades in
the same plane of rotation, then I would recommend that the propeller shaft
should be made in the manner shewn in Figure 2. S, S, T, V, is the propeller
shaft; W, X, W, a toothed wheel inside thereof; and J a pivot on which this
wheel turns. On the sides of the shaft just so much is cut away, and no more,
than is sufficient to let the four little wheels 1, 2, 3, and 4, be acted on by the
inner wheel W,X, W; and then racks, as before described, are placed in
contact with these little wheels. The dotted lines n, m, indicate the guard or
protector through which each rack passes.
I shall now proceed to describe the machinery whereby the blades can be
expanded or drawn in during the time they are in motion by the engine
power. A, Figure 13, represents a disc of metal with a flanged periphery, and
a¹ a wheel in the middle of it, which is of the same size and the same number
of teeth as the wheel Figure 17. A side section of A is given in Figure 15;
m, n, is a broad collar or socket, by means of which it is fixed, and turns truly
on the propeller shaft; B, Figure 14, is what I call a crescent wheel, because
so much of the metal of it is cut out as to leave the open crescent-like space C.
The part of the wheel which circumscribes this space has a number of teeth cut
on its inner face, that is, pointing inwardly. A small wheel similar to Figure 16
works freely within this crescent space C. Figure 18 is a wheel which is firmly
fixed on that end of the propeller shaft which is inside of the vessel; G is an
aperture in the centre of it, which is of the same diameter as the interior of the
shaft, and through this aperture passes the inner shaft J, Figure 20). In
Figure 19, F represents the wheel (Figure 17), which is fixed on the end of
the inner shaft, and E the little wheel, Figure 16. The wheel E is fixed
on the same arbor as the wheel D (see Figure 20), both being of the same

page_text: diameter and having the same number of teeth, only that D is twice as thick
as E. Figure 20 may be considered as shewing the machine in section,
where every part is represented in its proper place, ready for action. Here
P, P, is the end of the propeller shaft; B, d, is the crescent wheel; and a' the
wheel a' of Figure 13. The wheel a', Figure 14, is always in gear with
that part of the wheel D which passes through and beyond the crescent
wheel; L, L, is the drum or box which encloses the wheels E and F, and is
firmly screwed or bolted on the part C; M is the continuation of the propeller
shaft, which receives motion from the engines. Across the peripheries of A, B,
there should be some shallow notches made with a triangular file. The whole
machine being put together as explained under Figure 20, it exhibits the
external appearance shewn in Figure 12. By pressing a piece of cane or of
whalebone, or some other rather stiff but yet yielding substance, against A or B
while the engines are driving the propellers, the resistance will cause A or B to
put the wheels in the box or drum in motion, whereby the propeller blades
will be protruded or retracted as desired.
An arrangement for disconnecting and connecting the engine power with
the propellers is shewn in Figure 21. In this Figure l, m, represents the
portion of the length of the shaft which is connected with the propeller as
before stated; it is hollow throughout. S, T, is that portion which is driven
by the engines. An intermediate portion, a, q, of the shaft, also hollow, is
furnished with projections or teeth at the end a, fitting into similar teeth in the
portion l, m, of the shaft, and has also a slot K at about the centre of its length,
into which a key upon the portion S, T, takes; it is provided at the end g
with two collars n and o, between which is a loose ring c, fixed to a toothed
rack r, r. The teeth of the rack take into a pinion P, on the axis of which is
the toothed wheel x, driven by a pinion V, and winch handle W. H is the
frame for the gearing. Upon turning the winch W the ring c is carried
by the rack r, and acting on the collars n and o, throws the' teeth between m
and a into or out of gear, the part a, q, always turning with the crank
shaft S, T. In the Drawings illustrative of the different varieties of expanding
propellers before described the blades are uniformly represented as being flat,
but the same arrangements will in that case apply equally well where they are
curved, or at least with such modifications only as any engineer of ordinary
skill can readily supply.
The second branch of my improvements have relation to paddle wheels, and
consists in making them self-adjusting under all possible circumstances, whether
they are only under ballast or very heavily laden, or whether they have to work
in a dead calm or against the strongest head sea, and that without involving any

page_text: The
more strain or pressure on the engines and framework under one set of circum-
stances than under another. Paddle-wheels, as I propose to construct them,
can never be water-logged, as the common paddle-wheels frequently are, the
pitching and rolling of the ship not being able to derange the equilibrium of
their power and pressure on the water; and this will insure, as I hope and
firmly believe, to the vessels employing them a certainty and speed in
performing quite unattainable by any paddle-wheel hitherto in use.
floats of these self-adjusting propeller wheels may either be made of iron, brass,
copper, or any other suitable metal, or they may be made of timber and metal
combined. I have found by experiment that deal wood planks or wainscot
planks, when secured together by metal braces, bolts, and screws, will answer
the purpose excellently, and that by the application of proper paint, varnish,
pitch, &c. they may have great durability given to them. They are floats, not
in name merely, like the ordinary floats, but veritable floats; they are not fixed
tight and fast upon the radii or spokes of the wheel as usual, but are secured
upon the spokes of the propeller wheel by rings, staples, loops, or braces, of
suitable metal, and slide freely up and down the spokes, being at perfect liberty
to rise and fall with the waves of the occan. Or, instead of the rings, staples,
loops, or braces as aforesaid, I make a groove or channel at the end of each
float in the middle thereof, which groove or channel is fitted to the spokes of
the propeller wheel, so as to let the float slide freely up and down. When the
floats are made of timber, I recommend that inside such grooves or channels
there should be fixed pieces or plates of suitable metal, to strengthen them, and
to prevent them wearing away too fast. With regard to the form of these
floats, I do not limit myself to making them of any particular form. The form
of a parallelogram will do very well, but that which I most approve of is the
pentagonal, as exemplified in Figure 28 of the Drawings hereunto annexed
and herein-after described.
The 1st variety of these self-adjusting propeller wheels which I shall describe is
represented in Figure 23. D is the axis of the wheel, which is purposely made
of larger diameter than in the cominon paddle-wheel; g, g, h, h, are a pair of
spokes or arms on the upper side of the wheel, here represented as being
perpendicular to the water or horizon; and r, r, R, R, the opposite pair of
spokes, which are also perpendicular, and immersed in the water as far as the
line marked w, w. In case of a storm the leaward wheel might even
be immersed as far as D, for in that case the float would be up close to the
centre or axis of the wheel, consequently these self-adjusting propeller wheels
cannot be water-logged, through the paddle-wheel would be so under similar
positions. Each pair of arms has two metal springs attached to it, marked

page_text: centre on the drum of the wheel, and
As the floats rotate to the upper side
S, S, S, S, one spring being fixed by its
the other on the cross bar g, h, or r, R.
of the wheel these springs enable them to descend gently towards the centre of
the wheel, without jarring or injuring the machinery. It will be well to varnish
them with a solution of caoutchouc, to preserve them from the effects of
the water. b, b, b, b, are metal loops, on which the floats slide up and down;
the spokes A represents the upper float as descended to the centre, and B the
lower float, immersed and floating freely in the water. I do not limit myself
to making these floats of any given size or dimensions, but I consider it
essential to the success of this branch of my Invention that they should
be much broader and shorter than the floats of the common paddle-wheel. I
find by experiment that it is well to make them from one half to one third
part only of the length which is usually given to paddle-wheel floats, to which
dimensions I judge it advisable to add one fifth or one sixth part more of area
than is usually found in the floats of paddle-wheels; and I add to or diminish the
floative power of each float, so that the said one fifth or one sixth part of the
area shall, when immersed, always be above the surface of the water. I do
not, however, limit myself to these proportions, and merely state them as
furnishing good data for other engineers or constructors to go by in following
out this part of my Invention. I belive that to reduce the length of the floats
to one third the length they are made for paddle-wheels will not only insure
their more perfect action of self-adjustment, but will save two thirds of the
breadth across the midships that is now required for the paddle boxes.
further, in order that the full advantage obtainable from the use of these self-
adjusting propellers may be realized, I recommend that for large ships or
vessels the diameter of the wheel should be made a few feet more than for
ordinary paddle-wheels, so that the float may be able to catch the water and
be fully immersed therein on the windward side of the vessel at the time the
wind shall be blowing strongly. The fact that the floats on the windward side
thus increase their distance from the centre of the wheel in the same propor-
tion as the floats on the leeward side are floated up nearer to the centre of the
leeward wheel, shews clearly how these propeller wheels will in their combined
action always preserve their equilibrium of power and pressure as aforesaid.
And
A 2nd variety of these self-adjusting propellers is represented in the Draw-
ing, Figure 24. In this variety of propellers I make use for each float of one
or more levers, either to make the float slide gently down upon the drum of the
wheel, or to stop it altogether from going near the drum. This novel applica-
tion of the power of the lever to purposes of propelling is very nearly the same
in plan, and precisely the same in principle, as a simple machine which I

page_text: invented many years ago, but never till now have made known, which I call
the ships masts climber, or lever crane, for raising heavy bodies or weights, as
casks, ships boats, &c., and for various other useful purposes. An elevation
of this apparatus is given separately in Figure 25. m, m, represents a ship's
mast, or any like upright pole; P is a pair of pullies, either fixed in the top or
in a block having a socket fitted on the top of the mast or pole, so as to let
them swivel about, if required; or the pulley block may, by staples, rings,
and other suitable means, be placed lower down. d, d, g, g, is a sliding socket
of iron or any other suitable metal, in which is fixed the lever c, a, b, C; a is
the centre or fulcrum on which the levers turns; C is the end or ring of the
lever from which the weight to be raised is suspended; R, R, is a rope
fastened to the ring C, and passing over one of the pullies; S, S, is a rope
fastened to the lever at any convenient distance, say one third or one fourth the
length of the lever from the fulcrum. By pulling at the rope S, S, the weight
is raised up to the height required; and on ceasing to pull, the weight or body
raised will remain steadily at the position that it has attained; then, to lower the
weight, the end C of the lever is raised a little above the level (or horizontal
line), and kept so, by gradually letting out the rope S, S, a weight will be
raised much easier by drawing at both ropes, and pulling in such manner
as to keep the lever in a horizontal line, or nearly so, all the while it is going
up. In this manner I make any heavy body counteract the tendency to fall
down by means of its own weight, and the heavier it is the more secure it will
be from falling. A lever of the same kind or form as that just described is
used in the second variety of the self-adjusting propellers represented in
Figure 24. Two pairs of arms and the axis of the propeller wheel are here
shown. R, R, R, R, and S, S, T, T, are ring or loops that secure the floats
upon the wheel, and by means of which each float slides up and down. These
floats are made of timber, and braced and bolted together with metal fastenings.
I make them of two planks of timber, and cut away so much from each plank
as to form a recess inside for the lever a, b, and its weight W, to perform an
arc of a circle in, quite freely. A very strong bolt of metal passes through the
fulcrum of the lever, on which the lever freely vibrates or turns, and the bolt
is made secure by passing through strong plates or pieces of metal, also
properly braced upon the timber. The action of the lever will be readily
understood by inspection of the Drawing. As soon as any float rises to the
upper side of the wheel, the weight W, by its natural tendency to fall to the
centre, brings the short end of the lever to press hard upon the inside
of the spoke or arm R, R, and at the same time makes the inside of the
rings S, S, bear hard upon the inside of the spoke Z, whereby the descent

page_text: of the float is either totally prevented, or otherwise it slides gently down
towards the axis, and simultaneously therewith the effect of gravity causes
the weight W to fall down into the recess as far as it can, whereby the short
end of the lever is completely disengaged from touching the spoke of the
wheel, and leaves the lower float at perfect liberty to rise or fall according to
the rising and failing of the waves. In Figure 26 I have shewn a self-
adjusting propeller, with two levers to each float. a, b, a, b, are the two levers;
W, W, the weights, which just pass each other in the middle of the float.
Two levers may be used, extending nearly the whole length of the float;
the weight then required upon each will not require to be more than
about half what is required when the levers used are like those in
Figure 26; and when two levers are used to each float, the rings
that secure the floats upon the arms of the wheel need not be so loosely
fitted as in Figure 24, because when two levers are used each respectively
presses against the spoke of the wheel it is nearest to when by rotation it has
come to the upper part of the wheel. In all other respects the action of the
levers and floats is the same in this variety as in Figure 24.
A third variety of self-adjusting propeller wheels is represented in Figure 27.
In this variety a ratchet piece is attached to the inside of each arm, as shewn, being
let into a recess made in the arm for the purpose. If we suppose S₁ to represent
a section of the spoke of the wheel, then it will be observed that there is on each
side of the ratchet a smooth surface for the floats or their rings to rub against,
so that the teeth of the ratchet cannot touch either the floats, or the rings or
sockets they have to slide upon. In S³, n shews how the ratchet is placed in
the spoke of the wheel. P, P, Figure 27, represents each float; a, the driver,
which consists of two y shaped pieces, one within the other, made of strong
iron, or any other suitable metal. In the outer V piece there are slots,
through which two metal bars b and c are passed, each of which has a flat
head, and slides easily between the two V pieces. Each double y has two
metal rods or stems, which slide through apertures made for them in the float.
Now, by inspecting the upper float 1, as represented in the Figure 27, it will be
seen that the driver by its action downwards, has driven two bars b and c out-
wardly into the teeth of the ratchet, and so kept the float from falling upon the
axis of the wheel, while at the same time the position of the float 2 shews that
the driver by falling towards the extremity of the wheel y towards z has drawn
in the two bars b and c, and so left the float at perfect liberty to rise and fall
in the water as required.
Figure 28 represents a 4th variety of these self-adjusting propeller
wheels. In this, each float has two compound detent levers, each having a

page_text: weight in the form of a friction wheel or roller turning freely at or near
the long end thereof. I do not limit myself to making the lever always
in the form shewn, because the form may be much varied, and yet the
same effect be produced. The float 1, as here represented, shews that tho
effect of gravity has brought each of the roller weights into the position
marked w, and that thereby the detent 1 of each lever has become locked safe
in the teeth of the ratchet, which effectually keeps the float from falling to the
centre. If the aperture in the roller be truly in the centre this effect will
happen at the very instant the arm of the wheel rises to a position a few
degrees above the horizontal line. In like manner float 2 shews by its
position in the water that the effect of gravity has brought the roller weights
to the position m, m, and that the detents 1, 1, are free and detached from the
ratchets, whereby the float is left at liberty to rise and fall in the water as
required.
In the second, third, and fourth varieties of these self-adjusting pro-
pellers the recess or space which contains each weight and lever, &c. is
placed inside of each float, whereby the levers, &c. are protected from every
accident or injury that might happen to them if they were placed externally
upon the float.
As I have found propellers of the fourth of these varities by experiment
to be the very best of any of them, in order that other persons may be
enabled to make them act to perfection, I will, by way of instruction,
observe, firstly, that the roller is much better than a simple weight at the
end of each lever, for a simple weight, though passing over a smooth and
narrow surface, does not act with the same unerring certainty of locking the
floats as the roller weight does. Secondly, the points of the detents should be
so placed that when the float is on the lower side of the wheel these points
may be very near to the teeth on the ratchet, yet not so near but that they will
always keep clear of the said teeth in rising upwards. Thirdly, the teeth
should all be of the same size, and the first and last tooth on each rack should
be exactly opposite to the first and last tooth on the opposite rack. And,
lastly, the first tooth of the rack nearest the periphery of the wheel should be
at such a distance therefrom that when the float rests upon the rim of the
wheel the detent shall stand opposite the blank part of the wheel, and be the
length of one or two teeth distant from the first tooth, for otherwise the float
would not disengage itself and rise in the water as required.
The third branch of my Invention consists of a submarine feathering pro-
peller wheel of the construction represented in the Drawings, Figures 29, 30,
31, 32, 33, 34, and 34*. Figures 29 and 30 represent the two sides of the

page_text: framework which contains the feathering propeller wheel, shewn by itself in
Figure 33. Figure 29 shews that side of the frame which is towards the
starboard side of the ship or vessel, and Figure 30 that side of the frame
which faces the larboard side of the vessel. The letters a, b, c, d, indicate
the rim of each of these frames respectively. W, W, W, shew the place
and position of the feathering propeller wheel; V, V, V, V, are cylin-
drical sockets, through which passes the axis or shaft C of the propeller
wheel. In Figure 29, q, r, s, t, represents a circular guide piece or inclined
plane, which extends over about one hundred and eighty degrees or half a
circle. H, H, represent the horizontal line. The dotted lines q, r, and s, t,
are the actual inclines; each incline extends over forty-five degrees or there-
abouts; the space included between r and s is not inclined, but of equal
breadth or altitude all the way. It will be seen by referring to the Drawing
that the spaces from 7 to and from t to s are each forty-five degrees below
the horizontal line. In Figure 30, l, m, n, ó, p, represent the guide piece
belonging to this part of the frame; from m to the actual incline extends
forty-five degrees below the horizontal line; from p to o is the other incline,
which extends over about twenty-two and a half degrees above the horizontal
line. The part m, n, o, is not inclined, but of the same breadth or altitude
throughout its whole extent. Now, if we take the Figure 29, and bring
the letter to coincide with letter a of Figure 30, and make letter a of
Figure 29 to coincide with letter of Figure 30, then will the two frame
pieces stand exactly as they should do when the propeller is fixed therein and
ready for its work. The Drawing, Figure 31, represents a full or front view
of one of the segments or feathering propeller blades; and Figure 32 is a
section of the same taken through its greatest length. In both of these
Figures T and R represent the tongues or tangent pieces, which, by passing
over the inclined planes, reverse the position of the propeller blades or
segments. Figure 33 represents the feathering propeller wheel with all its
four blades or segments in their proper places (and also the position of the
guide pieces and inclines as before described when speaking of Figures 29
and 30). H, H, represent the horizontal line. II, B, is that part of the
machine which is nearest the bulk head. II, D, or II, K, is that part of the
machine which is nearest to the rudder.
The arrows shew the direction in
From the Drawing it will be observed
which this wheel should always move.
that the external pivot or axis on which each segment or blade turns passes
through the outer rim of the wheel, and also turns therein; and further, that
the internal or other pivot or axis of each blade or segment turns in and rests
upon the inner rim of the wheel marked a, b, c, d. g shews the stop or rest

page_text: inside the outer rim of the wheel upon which each segment rests, when its thin
edge has been brought to coincide with the plane of rotation of the wheel, in
consequence of the tongue or tangent piece R having passed over the inclined
plane l, m, of Figure 30. The action of this machine, when propelling a vessel,
is as follows: as represented in Figure 33, the propeller blade A is supposed to
have just reached half way between y and z, or, in other words, to have just
completed half its stroke, at which time also the segment D will very nearly
have come to coincide with the plane of rotation. The tongue T of the blade A
is now lying flat upon the guide piece r, s, and its broad surface will continue
to strike the water at right angles to the plane of rotation until it arrives
at z, r, when the inclined plane l, m, of Figure 30, will begin to act upon
the tongue R, and so reverse its position, and cause the thin edge of the
segment A to pass through the plane of rotation. By the time that the axis of
the segment A, following the direction of the arrows, has reached z, r, the
axis of the segment B will have reached y, s, and the inclined plane t, s, will
have acted upon the tongue T of segment B (see Figure 32), so that B will
now be acting upon the water with its broad surface at right angles to the plane
of rotation, and so will all the rest of the segments act in continual suc-
cession as required.
To make this machine impel backwards, or from the bow towards the
stem of the vessel, I put bevel gear teeth upon either of the frames,
Figures 29 or 30. It is not material which of these frames it is put upon; and
if upon the periphery, it matters but little whether it be upon the inner or outer
side of the same. I have then another level wheel with its shaft or axle passing
through the bulk head, or through the deck of the vessel, with the necessary
supports, stuffing box, &c.; the last-named bevel wheel may be of much
smaller diameter than the frames Figures 29 and 30. Now, all other things
remaining as before described, I turn the small bevel wheel until it causes
that part of the frames Figures 29 and 30, marked c, to come to the place
of d; or, in other words, I turn the frame of the machine until that part which
was before at the bottom comes exactly to the top or zenith, the blades or
segments all the while moving in the direction of the arrows (as explained
of Figure 33); the broad surface of the segments then striking the water with
a movement from the stern towards the bow of the vessel, will consequently
impel it backwards, and thus in a few seconds the effect of the propellers
will be entirely reversed, without stopping the engine, and without reversing
the motion of the machinery.
It may be proper to mention, that the frames, Figures 29 and 30,
may be connected together by two, three, or more braces or supports at

page_text: the discretion of the engineer or constructor; and also, that instead of
making the tangent pieces R and T (Figures 31 and 32) flat, they may
be made bent or rounding, it matters nothing what their shape may be,
so long as by passing over the inclined planes before described they produce
the required effect of reversing the position of the segments as before
described. The mode of finding the proper inclined plane is shewn in
Figures 34 and 34. The diameter of the circle, including the periphery of two
opposite segments, is here represented as being twelve feet, and the outer
diameter of the circle of the guides as being five feet and eight tenths of a
foot; then will ninety degrees be 4 feet, which will nearly take a sheet
of metal, &c., (see the Diagram h,) q, a, r, c, s, n, t, d.) In Figure 34°, from c
as a centre lay off this distance (4 feet) to the right and left side, and
divide each of these parts into two equal parts; cach part will then corre-
spond to forty-five degrees, or be equal to about 210 feet. Referring then
to Figure 32, I make the tongue or tangent piece equal to about one sixth
part the length of the chord line of Figure 31. Now, when I take half the
thickness of the thickest part of the propeller blade from the tangent T, there
remains the length v, T, which laid off downwards on the line a, r, c, s, n,
gives n, t, for the depth of the curve or inclined planes, t, as was required.
Again, in regard to the incline q, r, of Figure 29 (but h, r, of Figure 34ª),
so much must be cut away from the sheet of metal, &c. aforesaid, as will let
the tangent piece T of Figure 32, move quite clear and free from the guide
q, r, s,) of Figure 29, 33, and 34*; the moment that the tongue R begins to be
acted upon by the inclined plane or curve l, m, Figure 34, that is to say, as
soon as the tongue T reaches r, then
(Figure 34), the line through which the
blade passes, and bringing the end of the
against the other guide piece of Figure 34, the end of the tongue R will
indicate the curve or incline m, l, or show how much must be cut away in
order to bring the propeller blade into the required position of causing the
thin edge thereof to cut through the water as aforesaid.
by making the dotted line x, y,
centre of the axis of the propeller
tongue R (of Figure 32) to touch
I propose that two propeller wheels of this feathering description should be used
in every large ship or vessel, one to be placed to the right and the other to the
left of the stern post, in an air and water tight chamber, or false stern or false
bulkhead such as is afterwards described. When only one of these feathering
propeller wheels is used, I substitute a pivot x, x, y, y, shown by dotted lines in
Figure 30, for the case or frame containing the propeller wheel to turn upon,
and I also fix a strong cylindrical tube of iron, or any other suitable metal,
on the top of the frame as indicated by the dotted lines g, g, h, h, which pass

page_text: through the deck of the vessel, then through a slot e, f, on the right, and
another on the left passes a strong cross bar of iron, &c., at each end of
which bar is fixed a connecting rod attached to a crank, which is fixed upon
the shaft or axle that turns the propeller wheel; the cross bar is joined to a
strong bar of iron, &c., which moves freely inside of the cylindrical tube
g, g, h, h, and receives the alternating motion as required from the engine, &c.
Then to reverse the effect of the propeller, or to impel the vessel backwards,
we have only to make the frame of this machine turn half way round on its
pivot, until that part which before was towards the rudder shall now face the
bulkhead of the vessel. The two pivots last described should be at equal
distances between the two frames Figures 29 and 30 as before described.
I also work the single feathering propelling wheel by means of bevel gear
wheels in manner following (see Figure 30): I still retain the cylindrical
tube g, g, h, h, to which I add a box or frame, indicated by dotted lines K, K, 9, 9;
and inside of this box or case or frame I place a bevel wheel, indicated by the
dotted lines S, S, t, t; the shaft of this bevel wheel is inside of the cylinder
g,g, h, h, and receives its motion from a wheel or other mechanical appliances
inside the vessel. The bevel wheel S, S, t, t, communicates its motion to
another similar wheel fixed on the shaft or axles of the feathering propeller
wheel, by which means the propellers are made to act in all other respects as
herein-before described. The feathering propeller wheel may, like a paddle-
wheel, be placed on the side of vessel about midships, and will act there
cither above or below the water; it may also be worked horizontally at the
bottom of the vessel if required, and when placed in the stern part of the
vessel it will perform the functions of a screw propeller.
The fourth and last branch of my Invention consists in certain improved
modes of constructing vessels that are intended to be moved by submerged
propellers, whereby the said propellers can be conveniently stopped and
unshipped at pleasure. Instead of putting the propellers in the dead wood as
was formerly done, I appropriate to the purpose portions of the vessel known
as the stern part and bulkhead, and compensate for the appropriation of these
by making the fore part of the vessel proportionably longer. When the
vessel is round at the stern part, I make that part of the vessel as nearly a
true semicircle as I can, as represented in Figure 35; on a level with the
keel of the vessel, or nearly so, I construct a very strong circular framework
or railway, extending all the way round from S to S; this framework may
be of timber, or of timber and metal combined, but I prefer making it entirely
of metal, as the same weight of iron would be stronger than the same weight
of timber. The lower end of the stern post is fixed into or upon this strong

page_text: circular frame; the stern post itself I make larger and stronger than in
common sailing vessels. The circular frame has a strong metal flange several
inches high, in order to prevent the circular doors of the chamber or falls
stern from being carried away; a similar circular frame secures the said doors
at their upper part. The part marked i, k, is a continuation of the side or
wall of the vessel. The whole of the space F, F, F, forms what may be called
a false stern. P, P, is a platform or box, which is secured to and slides as
required backwards and forwards upon the beam B, C; at C it turns on a strong
pivot; the end B traverses about in a kind of groove formed by two strong
horizontal flanges. On the inner side of the circular frame N is an air-tight
transfer chest, which should be made of iron or some other strong material.
This chest has two doors, g, h, and d, d. g, h, is that door nearest the fore part
of the vessel; and d, d, is the one next to the false stern. The form of this
door is shewn separately in the Figure 35*. R is a toothed rack acted on by
a pinion wheel and handle when slided backwards and forwards, so as to open
or shut the passage n, n, in the wall of the bulkhead by which the men enter,
and through which the propeller shafts and blades, when required to be repaired
or to be replaced by new ones, are passed. The frame through which this
door d, d, slides has a recess all round it in the inside of it. This recess I fill
with suitable packing, well lubricated with tallow or any other suitable substance,
so as to render it effectually air-tight and water-tight. In regard to the large
circular doors which shut off the water of the sea when required so to do, they
must be made very strong, so as not to bend or give way with the weight of
the water pressing against them when the water is driven out from the false
stern. An outside view of one of these sea doors is given separately in
Figure 35b, and a plan in Figure 35°. A, X, is the upper part of the door,
and v, v, the lower part, which traverses upon the circular railway. I put
friction wheels on the lower side, that it may move more easily within an inch
or two of three of its sides, videlicet the sides v A, AX, and v X. I fix a list
or welting of india-rubber, or some other suitable elastic substance, as is indi-
cated by the dotted lines. Each door is shut by making it traverse the railway
till the end a, Figure 35, is brought close to b at the stern post, and this shut-
ting up may be effected in several ways. One method is by fixing the stern post
a pulley with points or teeth that pass through a chain, and fixing another
pulley with a very deep groove at S, and then passing an endless chain over
both these pulleys, and connecting it with a suitable staple or ring, &c. fixed
about the middle of the sea door outside; or a strong circular toothed metal
rack may be fixed on the middle of the outside of the sea door; as indicated by
the letters m, c, d, and then upon a shaft of metal may be placed a pinion w,

page_text: which shaft may be passed through the deck, &c. of the vessel, and be turned
by a suitable handle. Inside the vessel there may be a larger wheel, which
may be turned by a pinion wheel to increase the power if found necessary. A
third method is to fix the toothed rack upon the sea door at the end near m,
and let the other end of the rack extend and pass into and through the middle
of the stern post, there to be acted upon by a pinion wheel, &c. as already
described. The mode in which the sea door is made to press against the
opposing parts of the vessel, so that no water can enter, except through the
bottom, is represented in Figures 36 and 37. In Figure 37, a, b, and c, d,
represent the stern post in elevation. n, n, is that part of the sea door that
presses against the stern post when the door is shut. 1, p, l, p, l, p, are three
very strong (metal) levers; p, p, p, bolts which serve as pivots on which the
levers turn, which bolts pass into the stern post, where they are made fast;
T, T, is a strong bar of iron, &c. as long as the length of the sea door. To the
ring at the top a strong chain is fixed, and by tightening this chain by means
of a windlass, &c. the short end of the levers press against the sea door, when
the india-rubber welting will be pressed so close as to prevent the water passing
through and between the door and the stern post. In Figure 37, c, d, is the
lower end of the stern post; and in Figure 36 the position of the levers at the
stern is indicated by the dotted lines b, b. The square of dotted lines at a
(Figure 35) indicates that there is placed there a strong frame of iron, &c., to
which the levers are fixed, as has been before explained in regard to the stern
post, and the levers on the frame at a are made to press the end of the sea
door against i when brought into its position there opposite to a. A circular
frame connected with a set of levers is fitted from a to b to near the top of the
door, and by similar means to those herein already described. The top of the
door throughout all its length is made to press the india-rubber tightly against
that part of the vessel, whereby the water is prevented passing through that way.
The water is expelled from the false stern in manner following:-To
every steam-engine I attach or connect a blowing cylinder similar to those
made use of in many blast furnaces (being made on a plan similar to the com-
mon forcing pump). With this blowing cylinder I connect a suitably large
strong metal tube, having a stop-cock or plug. The other end of this tube I
place in connexion with the false stern by making it pass through the wall of
the bulkhead, and having it firmly fixed therein. Now, supposing all this to
have been done, I next turn and open the stop-cock in the air tube, then set
the engine to work, whereby the blowing cylinder is brought into full action.
The false stern is presently filled with atmospheric air under a certain degree
of compression, and the water is thereby rapidly driven out at the bottom

page_text: of the stern chamber, which is then ready for the workmen to go on with
their work. I may here remark, that if the stern chamber was only mode-
rately water-tight, so great would be the power of the steam-engine that the
water would still be driven out faster than it could come in, through the india-
rubber welting not being pressed so tight against its bearings as it ought to
be. To ascertain from time to time how far the water is drawn out, I fix a
brass or copper tube, with a stop-cock, into and passing through the wall of
the bulk head or false stern firmly and perfectly water-tight, just on a level
with the lowest floor of the vessel, and also in like manner several other such
pipes with stop-cocks, at different places higher up in the bulkhead.
I shall now show how I introduce the workmen and materials into the false
stern. The door d, d, of the transfer chest, is always supposed to be shut, except
when the workmen want to pass into the false stern, or when any materials are
required to be introduced into it. Now this door d, d, being shut, the other door
g, h, is opened. The men go through the door g, h, into the transfer chest, and
take with them the articles required. When this has been done, the air-tight
door g, h, is shut, the other door d, d, is opened; the workmen can then walk
into the stern chamber, and convey their tools, propeller blades, &c., or anything
that can be contained in the chest, into the stern chamber, and so proceed with
their work as easily as if it were to be done in any other part of the vessel.
The plug of the transfer chest (see Figure 36) I make externally in form
like the plug of a common stop-cock; but instead of being solid, I make it
hollow, yet sufficiently strong, and enclose it in an air-tight case of a corre-
sponding shape. I make it about seven feet in diameter at the bottom, and
about eight feet diameter at the top. It turns on a strong pivot at C, and on
the upper part it has a similar but larger pivot passing through an air-tight
stuffing-box, by which it is turned about. The passage through this plug
should be about six feet high, and about two feet wide all round the case that
contains this plug. At the opening next the false stern is a recess for packing
so as to render the plug both air-tight and water-tight. I find that half the
plug will answer better than the whole, if we take it in the direction of m to k,
though this would render the transfer chest considerably larger. That part of
the plug exposed to the water is coated with brass or copper, and all the other
parts which are exposed to the action of the water should be made of good
iron, and coated with brass or copper. The manner of transferring articles
into the false stern, and the passage of men thereby, is managed in the
same manner as has been already explained in describing the transfer chest of
Figure 35. Figure 36 is intended to represent a vessel whose stern is flat-sided.
Here the sea doors are flat, and move upon large hinges at h, h, which should

page_text: extend the whole height of the doors. They are drawn towards the stern post
by means of a chain worked in the stern post, and they are opened and turned
flat upon the side of the vessel, as shewn by the dotted lines x, y. In all
other respects they are managed in the same way as the circular sea doors.
In large vessels I propose, as before stated, to use two of my expanding screw
propellers, in which case two additional stern posts will be required to support
the axes of the propellers, and the new stern post should be at t, as shewn in
in Figure 35. The exact position will of course depend upon the diameter of
the screws to be employed. I may further observe, that when two propellers
are placed in the false stern, then I believe the best place for the transfer
chest would be midway in the bulkhead, so as to open upon the moveable
platform. The proper position for the propellers is shewn in Figures 35 and
36 by the included spaces K, K. The advantages I expect to be gained
from the use of two such propellers are, that they may be worked at a less
velocity than a single screw, and thereby prevent waste of engine power, by
lessening the friction in passing through the water, and that the commander
of the vessel will always have it in his power (supposing my expanding screw
propellers to be employed) to increase or diminish the speed of his vessel, so
as to suit every sort of emergency that can arise; and further, that the said two
screws would always enable the vessel to claw off from a lee shore in safety.
And having now described the nature of my said Invention, in the several
parts of which the same consists, and the manner in which the same is
performed, I declare that I claim as follows:-
First, I claim in respect to the first branch of my Invention, the different
modes of constructing submarine or screw propellers, before exemplified and
described, whereby the area of resistance may be expanded or contracted as
circumstances may require, of whatever form or variety of (regular) curvature
the same may be, and whatever their angles of inclination to the planes of
rotation.
Second, I claim in respect of the second branch of my Invention, the con-
structing of paddle-wheels with self-adjusting floats, according to each and
every of the different varieties thereof herein-before exemplified and described,
or any other varieties founded on the same principles, that is to say, having
propeller floats, which move more or less freely up and down the arms or
spokes of the wheels, and are continually varying their distances from their
centres of motion, or which descend to the axis or centre part of the wheel
(when by rotation they arrive at the upper side thereof) without collision or
injury to the floats or to the other parts of the machinery, or which when
they rise by rotation to the upper side do not descend to the axis or centre

page_text: thereof, but are safely and firmly locked, at a certain distance from the centre
of the wheel, whereby jarring, collision, and injury to the floats and other parts
of the machinery are prevented and guarded against, or which by the force of
gravity descend a required depth into the water, and by the force of their
buoyancy always float freely in the water, rising and falling with the waves,
and thereby preventing the wheels being water-logged, and avoiding other
inconvenient effects attendant upon the paddle-wheels and other propellers
hitherto made use of, or which, without any trouble or care on the part of the
ship's engineer, shall always adapt themselves to the level of the ship's load
line, or line of immersion, or which, in short, shall always adjust and suit them-
selves to the circumstances of the waters in which the ship or vessel sails,
whether the waters be smooth or rough, or the weather be calm or boisterous.
Third, I claim in respect of the third branch of my Invention, the sub-
marine feathering propeller wheel before described, and the manner and
method therein embodied of feathering or reversing the positions of the blades,
and of thereby changing or reversing the motion and direction of the vessel.
And fourth, I claim in respect of the fourth and last branch of my Invention
the mode of constructing vessels intended to be moved by submerged pro-
pellers, whereby the said propellers may be conveniently shipped and unshipped
at pleasure, and more particularly the false stern, and air and water tight
chambers, with their respective appurtenances, by which the said object is
accomplished, as before described.
In witness whereof, I, the said Thomas Oxley, have hereunto set my
hand and seal, this Twenty-first day of February, in the year of our
1