US3129A - Improvement in s - Google Patents

Description

PATENT FFICE. ,-y

HORACE EVERETT, OF IVINDSOR, VERMONT;

IMPROVEMENT IN SUBMEBGED PRoP'ELLER's.

Specification forming part of Letters Patent No. 3,129, dated June 1843. Y

To all whom it may concern,.-

Be it known that I, HORACE EVERETT, of lVindsor, in the county of Windsor and State of Vermont, have invented a new and useful ImprovementforPropellingVessels by Steam, called The Horizontal Shifting Paddle- Wheel, with or without its, guards or caisson and I do declare that the following is a true and exact description of the construction and operation of the same.

The nature of my invention consists in providing a horizont-al paddle-wheel, placed partly within and partly without the vessel, the paddles of which shall, when without the vessel, vact as propellers. and before enteringv within it'shall, by fixtures in the vessel, be turned edgewise, and in that Vposition pass round within the vessel, and on passing out shall resume their position as propellers; and in providing guards to protect the part of the wheel without the vessel against external injury, andin providinga caisson to inclose the wheel when the vessel shall. be propelled by sails, and to render repairs of the wheel practicable without having the vessel put into dock or laid down.

The description has reference to the acoompanying drawings, making a part of thisy specification, made on a scale of one inch to a foot, and'noted decimally in figures on the unit of a foot.

'Ihere are five figuresl in the drawings, to which the references are noted in the margin, and have relation to the small capital oritalicized type, viz: v

Figure I is a horizontal section of the-paddle-wheel,on the starboard side ofthe vessel, taken at the top of -the upper arms. Fig. II is a vertical section of the same, drawn through the upper paddle-arms on the transverse line, exhibiting y also the main arms. Fig. III is a vertical section of the main arms and rims, and of the supports between the rims. Fig. IV is a horizontal section of a paddle-arm and paddle through the shackle. Fig. V is a vertical section of the guards and caisson and the cog-wheel out of place.

` The principle lines and circles referred to in the description are: the transverse line la, drawn from the center of the paddle-wheelat a right angle with the side of the vessel; the roller-line l, drawn from the center of the paddle-wheel tothe center of the receivingroller K; the center line 1c, drawn from the center of the paddle-wheel through a pointn in the paddlecircle, without the vessel, distant from the intersection 'm of the roller-line and paddle-circle a space about an inch (0.1) less than half or the whole length-of a paddle c, and the inner and outer rim-circles d e.

The paddle-circle g, the vinner and outer paddle-circles h t', and the paddle-arm circle j, respectively, are described by the motion of the outside of the paddle when shifted, by the inner and outer ends of thepaddles when acting as propellers, and by the end of the paddle-arms?.

The drawings are not made in reference to a necessary size of the wheel or of its parts, but merelyA for the illustration of the description, The dimensions of the parts will necessarily have relation to the size of the wheel, the depth of its immersion, and the velocit-y required. The space within (from the outside of) the vessel occupied by the wheel will be about six-sevenths (S5-100 on the diameter) vof the paddle circle, affording sufficient space between the shaft and inside of the vessel for the crank. The wheel may be immersed to any depth that the construction of the vessel will permit. The position of the wheel is no part of the invention claimed. The wheel is lmadeentirely of iron, (unless where otherwise noted.) The shaft'A, of cast or hammered iron of suflcient diameter (1.0) for strength, is made round above the upper hub and six or eight square where it passes througlrthe hubs, having a shoulder (which may project an inch or two) to rest on the surface of the upper hub.,.; It extends downward Vto Within aninch (0.1) of the bottom of the lower hub and upward'so far as is necessary to connect its crank with the steam-engine. It is supported by clamps above the covering of the wheel-Jitgtud at the bottom rests on a gudgeon 2, {itteffinto a socket 3, placed in the frame of the vessel. -Above the gudgeon is a projection/.11, of greater (0.4) diameter than thev shaft, having its upper surface turned level, audabove that is a section 5, of aboutan inch (0.1) high, vcorresponding with the square of the shaft l,and'itted to enter the lower hub up to the projection, all cast solid and in one piece. The object of the section is to prevent theunscrewi-ng-of the fastening-rod on reversing the motion of the wheel. The shaft A bottom of the screw in the gudgeon, having Y on one end a strong square head, (which is let down on the `top of the shaft by a cut in the top of the cra-nk,) by which it isvturned, and

a screw at the other end, which cdnnects it The shaft is fastwith that in the gudgeon. ened in the hubs in lthis manner: Thevinner cylinder of the drum is placed between the hubs, (in the manner hereinafter described,)'

which are firmly secured on it by bolts with nuts. The gudgeon being put in placein its sockets, the hubs are placed upon -.it.,`and (the squared section entering the lower hub) are i brought to a firm rest upon the surface of the projection. The shaft is then inserted'in the hubs and the shoulder brought to a li-rm resti upon the upper hub. The fastenin g-rod is inl serted-in the bore and screwed into the gud' geon, bringing the head home upon the top of By this the shoulder and projec-4 ,tion are brought iirm against the upper and lower hubs and the shaft firmly secured to the shaft.

the wheel. The shaft thus placed can be taken out, reinserted, or replaced when nec-` essary.

There are two hubs B, each with its arms cast or made in one piece, and are of the same pattern, having their corresponding faces toward and opposite to each other. The hubs are of adiameter (2.0) sufiicient toreceive the inner cylinder of the drum, the bolts by which they are fastened together, and the heads of the drum, and of sulhcient thickness (0.25)

to sustain the action of the shaft and to support the arms, (the increase of thickness over that of the arms being on the inner sides.) They have an aperture in the center correspending with the squaring ot' the shaft. A flange 8 projects inward from the inner side of the hubs next to the shaft about an inch, (0.125,) squared inside to the shaft. The out,- side of the Hange is a circle of as much greater diameter (0.2) than that in which the square for the shaft is inscribed as shall be necessary tor their proper strength. The outside ot the flanges and the inner side of; the hubs are turned smooth to receive the innercylinder of the drum. The outer surfaces otl kthe hubs and arms are turned to alevel, and when in place those surfaces are parallel to each other. The hubs are secured by bolts 0, (ou tside of the inner cylinder,) and are placed at. such distance apart (2.5) as is proposed for the depth of the wheel, having a head on the one end and a nut on the other; (or, if shouldered to meet the inside of the hubs, by a nut at both ends.) Y

The number of arms C depends on the size of the wheel and the number of paddles. The number should be such that the paddle-arms may be placed between them, and that each arm have the sa me distance on each side from the paddles. A wheel With twelve arms (the one described in the drawings) will admit of only one paddle between them. A wheel of the same size with eight arms will admit of two paddles between the arms. The width v(0.25) of the arms where they proceed from the hub is wider than where they connect (0.2) with the rim. They are of the same thickness (0.2) of the rims, or may be square at both ends; They are connected with the rims by halvings 10, made onthe outer side of the arms and inner side of the rims. There vare flanges on the inner side of the ends of the arms corresponding with those on the rims. The rims D are made in four sectionsof the same thickness (0.2) as the arms, and as Wide as is necessary (0.5) to gi ve firmness to their connection with the main and paddle arms. Their outer surfaces are turned down to a level vwith the arms. Their edges are turned in circles. Their inner sides are turned level up to the flanges and parallel to the outer surfaces. The flanges 11 of the rims project inward from the inner side ofthe rims at the inner ri m-circle so far (0.125) and are so thick (0.075) as is necessary to keep the outer cylinder of the drum in place. They are turned round to receive that cylinder. The rims are halved (l0) on the Quter (or on the upper) side at the center between the main arms to receive the paddlearms. Aplate of copper or other metal is fastened ou the inner edge of the rims against the halvings to secure the perfect tightness of the drum, especially when a paddle-arm is taken out for repair. The rims are secured in place by pillars 12, round or tlat-if flat, about halt' an inch thick (0.05) and about five inches Wide (0,425)-placed between them where the arms connect, shouldered at both ends, the whole width between the drum and the outer edge of the rim, for the purpose of keeping them parallel. They have bolts at each end, which pass through the rim and stays and are secured by nuts.

The drum E of the Wheel is made as large (11.15) as is necessary to sustain the Whole Weight of the wheel (and incumbent Weight) when immersed in water, (2.72,) and made perfectly air-tight (by its accurate construction, secured by paint or proper cement.) When the drum is found too buoyant, the equilibrium is restored by letting in Water through an aperture in the top, securedby a sliding valve 19. 'lhe inner cylinder 13 of the drum is made of cast-iron, of the length (2.0) necessary to the depth ot' the wheel, and ofsutlicient thickness V(0.075) for strength. The outer cylinder 'la ot' the drum is made of sheet copper or iron ot sufficient thickness (0.015) for strength, of the same diameter inside as the outside of the rim-lianges, of the depth (2.1) of the distance of the inner sides depth of the paddles necessary.

of the rims, turned at each end to a uniform with copper, (of a less thickness (0.0075) than the outer cylinder 16,) formed between concentric circles, the inner onelapping onto the hubs and the outer one onto the rims a suffi- .cient space (0.1) to be fastened down by screws 18, passing through the heads and circular screw-plate 17, of an inch Wide (0.1) and half an inch inl thickness, (0.05,) placed on their surface at the edges, into the hubs and rims. The capacity of the drum may be increased or diminished by the thickness orthinness of the boards. They cannot, however, be raised beyond (0.15) the nuts on the Wheel Without rendering an increase in the The board may be halved down to receive the plates and heads of the screws. This mode of regulating the buoyancy ot' the drum maybe of some importance. In the wheel described the drum displaces two hundred and sixty-six and two-tenths cubic feet of water, and the iron-work ofthe wheel, outside of the drum and in the water, displaces twelve and eighttenths more, making two hundred and seventy-nine, which, at sixty-two and live-tenths n i Pounds. pounds per foot, is 17,437 while the iron-work weighs only about. 16,350

Reducing the thickness of the board to oneiourth of an inch will reduce the buoyancynine hundred and sixty-two, or reducing the depth of 'the drum to two and fty-iive onehundredths will restore the equilibrium.

, The paddle-arms F, ot' east or hammered iron, are placed in the center between the head, in a line to the eye of the arm, and of' the same thickness (0.2) as the rims. To give additional strength, if necessary, the part of the side nothalved lnay be parallel with the other. Each paddle-arm is fastened to the rim by a separate bolt and nut. The head 2l of the paddle-arm is made by the line of a circle of such radius (0.25) as shall give it sufficient strength drawn (from the centerof the eye) from one side of the arm round to the other. The heads of the paddle-arms are halved 22 on the upper side to the neck to receive the paddle-shackle, and the halving across the neck forms a shoulder 23, corresponding to the shoulderon the shackle. The paddle-arms may be cast with the sections of pillar at the rim.

They are ofv the rim; but in case of accidentthey cannot be repaired without taking up the wheel. Thestays G of the paddle-arms are rods of the best hammered iron, of sucient width (0.125) and thicknes (0.1) to sustain the strain to which they may be subjected, having circular heads and eyes at each end, like the heads of the arms, to receive the paddle-axle at one end, and at the other the bolt of the The outer head forms the outer jaw of the upper paddle-shackle. The cross-stays G2 pass inside the paddle-arms from the-axle at the rim of the one to the axle nearv the head of the other. Their rods are of round iron of sufficient size (0.06) to bear the strain to which' they may be subjected. Their heads and eyes are similar to those of the stays. They are brought home by the nuts at the rims; but at the other end a small space (0.02) is left open between the head and the arm or shackle. They are so bent in the middle as to pass each other. The heads are so made that when in place they are parallel with the arms. The outer head of one of them forms the upper jaw of the lower shackle. Their object is to regulate and preserve the parallelism of thepaddlearms. The paddles H are ofthe same curve as the paddle-circle. Y Theyare made of sheetiron of suicientthickn ess (0.025) for strength, and of such length (2.0) (horizontal) as the construction of the wheel will permit, and in depth (3.5) extending three or four inches above .and below the drum. The paddleshackles 24, of a thickness (0.08) a little less than the halving of the head, of the best hammered iron, are made to correspond withV the heads of the arm, and have corresponding shoulders 25 at such point that'when in contact with the arm-shoulders the paddle shall rest at right angles to the arm to prevent turning inward when passing within the vessel. The shackle is fastened to the concave side of the paddle by bolts (and nuts) passingtrough an iron back 24, (madeV in one piece with the shackle, and ofthe same thickness,) one side lit-ted to the concave side of the paddle, and the other shaped to lines (straight or concave) drawn from the ends of the paddle to the shackle in the direction of the centerof the eye. The eye of the shackle is of the same diameter` (0.15) as that in the arm below it,the lowerone being smaller than the upper one lby the depth `of the cut of the screw on the axle. The eyes of the shackles may have a brass lining secured bya piu before they are ful-ly shifted. The paddles maybe made ot' cast-iron, rendered malleable, and the shackles cast on them. The shackles 26 are secured tothe heads of the arms by an axle having ahead at the upper end anda nut at thelower end. A screw iscut on the axle for twoor threeinches (0.2) next (within) the arms, and also in the middle. On the screws next the arms (the cross-stays being in place) -nuts 27 are run and brought nearly up 'against the cross-stays or (if not used) against the arms. Their object is` to make and -securea perfect parallelism of the arms. A third or center shackle 2S is fastened lat the center of the paddle, `with the eye so large as to have no bearing on the axle. A nut 29 of brass is screwed up under it so as to sustain the whole weight of the paddle and relieve the arms of all friction. The nut is to be screwed u p from time to time so as to keep the arms relieved. For the purpose of rendering frequent adjustments unnecessary, a fifth ofan inch space (0.02) is left between the shackles and the stay and cross-stay; and on each adjustment the shackles may be raised to the top of the space, and thus nearly the whole friction and wear is brought to bear on two parts which can be easily replaced.

The wheel-pit I, within the vessel, extends an inch or two (0.1) beyond the paddle-circle.

- Outside of that it may be in such form as shall be best adapted to the strength of the vessel. There must be suiiicient space (0.2)

above the upper end of thel drum to permit the gudgeon being raised out of the socket. Below the drum ,no more space (0.1) is necessary than to permit the wheel to run free.

A circular groove it is cut in the top and bot-` tom of the wheelpit about two inches (0.2) wide and of a depth to receive the ends of the paddle, the inner side of which is alittle less (0.075) than the paddle-arm circle, and is banded with iron turned true and smooth, for a guide k for the paddles While passing within the wheel-pit. The wheel-pit (when the caisson is not used) may be covered permanently, an aperture being left for the insertion of the Shaft;

For the purpose of shifting the paddles Vvarious means may be used, all, however, depending on the same general principles. Two small rollers K L of the same diameter (1.0)

and on the same axle are placed horizontally at each end of the wheel-pit in such position dle-arm circle and cut the inner paddle-circle i twice at points in a li-ne with such center, having their periphery three or four inches ing-wheels or are fully shifted. The parts of,

these wheels within the wheel-pit may be countersunk in the frame of the vessel above and below the drum. The upper wheel is suspended by clamps above the covering of the wheel-pit. Its shaft is inserted and fastened in the vsaine manner as the main shaft, having no gudgeon, however, at the bottom, and the projection (formed as a plate) is countersunk in the bottom of the hub, so as to be level with it.V The lower wheel is dropped onto a bolt fixed in the frame of the vessel. ing-wheels may be enlarged, so that the periphery shall cut the inner paddle-circle at about sixteen and one-half degrees aft the transverse line, at which point the paddles will commence shifting. These two sizes are considered as the extremes between which shifting-wheels should beconstructed, and lthe larger they are the better will be their operation.

The mode of operation in shift-ing the paddles is this: The paddle-wheel being in motion, the inner ends of the paddles are brought in contact with the periphery of the shiftingwheels at the point where they eut the inner paddle-circle, and (the paddle-Wheel moving on) the inner half of the paddle is carried up on the shifting wheels (without friction, they moving at the same time) until the center of the paddle-eye is in the center line. The paddle is then at right angles with the paddlearm, and the shoulder of the shackle is brought down, upon the' shoulderv of the arm, and in that position (the paddle moving on) the inner (now the back) end passes on the rolling shifting-wheel until the outer (forward) end is received on the roller, uponwvhich it passes (leaving the shifting-wheel) in to the wheelpit. Within the wheel-pit Atliefo'rward end is prevented from turning inward by the shoulders. The action of the inclined end against the water tends to keep the' paddle down upon the shoulders, and should ittiincline outward the back end will be stayed by the guide-circle k, and it is thus kept in position edgewise to the line of its motion until it comes to the side of wheel-pit, where it is to pass out. When the paddle begins to m'ove out of the wheelfpit, its velocity being greater than that of the vessel, the inside of the outer end of the paddle is resisted by the water and the outside pressed back upon the dischargingroller, against which it turns without friction (the roller turning at the same time) untilthe inner side of the inner end of the paddle is ,brought home against they paddle-arms, and the paddle is thus brought into a position to act asa-propeller. The spaces passed through bythe outer Jhalf of the paddle Vbeing greater than thosepassed through by the inner half, lin that proportion the resistance against the outer half is greaterthan that against thein- ,ner half, and that major resistance keeps the paddle in a propelling position until it again meets the shifting-wheels. In the wheel described the axle is placed in the center and the resistance against the outer half cornpared with that against the inner half is nearly as 47to 4:1. the paddle as to give to the outer half onlya sufficient major resistance to secure it in position as a propeller. A greater than this will unnecessarily add to the power required to shift the paddles. The properline'of division depends on the sizeof the paddle-wheel, the y length of the paddle, the depth of immersion,

and the velocity required. 0n reversing theV motion of the paddle-wheel the paddles will be kept shifted within the wheel-pit by the guide-circles, and on passing out by the receiving-roller until they are received on the aft side of the shifting-wheels, over which they will pass. On leaving them, the resistance now also being greatest on the outer end of the paddles, they will be kept in the same position (upon the shoulders) `and in that position pass into the wheel-pit. Any irregularity in entering will be corrected by the discharging-rollers. It is evident that on the vreversed motion the paddles cannot act as propellers. This is an admitted defect; but the great object is to go forward and not backward, yet it is believed that the action of the wheel will still be sufficient to back the vessel for the usual purposes for which that operation is needed, excepting to draw the vessel from a grounding. This is matter of opinion, and the theory of this opinion will now be stated. The drum of the wheel, so far as it is without the vessel, will act as a propelling-power by its action (or centrifugal force) against the water. The transverse section of the arms and paddles will also act as propellers, and thus a back motion will be given to the vessel unless prevented by a reaction within the wheel-pit. The action and reaction within the wheel-pit is.(supposed to be) between the paddles and the internal surfaces of the wheel-pit, and not between the paddles and the external water in opposition to the motion of the vessel. The reaction within the wheel-pit, then, has no tendency to retard the motion of the vessel otherwise than as it retards the motion of the wheel. It is therefore merely a loss of power. If these principlesbe well founded, it may be important to extend the drums nearly to the outer rim-circle and lessen its depth by placing the arms nearer together. The at pillars 12 between the rims may have the same effect, and if absolutely necessary they might be extended even to the paddle-arm circle, yet they would lessen the forward motion by the waste of power to move them in the wheelpit. If the drum be extended to the outer rim-circle, the pillars must be placed inside.

The axle should so divide.

vThe second mode of shifting the paddles is by substituting gangs of rollers N" for the shifting-wheels. from four to eight inches diameter (0.5) and about an inch thick (0.1) vplaced in two alternate lines so near together as to merelyleave room between those in one line for the arbors of those in the other. They are set in the segment of a circular block of such a circle that the outside edges of the rollers shall form a similar circle to that of the wheels; and those blocks are .firmly fixed in the frame of the vessel, but capable of being taken out for repairs, and are placed in the same relative position as the wheels. One gang vand one wheel may be used together, the outward cir` cles being the same. It may be more convenient to use the gang above the drum, Where it can be more easily placed than tho wheel, and the wheel below it. The circle of the gangs N may be enlarged (see N2) beyond what can well be done as to the shifting'- wheels. They are not confined to the form ot' a circle, but maybe formed on any curve desired.

Third-Instead of either of the preceding modes the paddles may be shifted on inclined planes O. To lit the paddles for the inclined planes, a square bar t of iron of suf- A icient size (0.1) for strength, of the length of the perpendicular depth of the paddle, having round axles three or four inches (0.3) long at each end, on each of which is placed a brass or iron roller u of iive or six inches diameter, (0.5,) and from one to two inches thick,(0.l5,) and from one to two inches (0.15) from the end, is to be fastened by bolts and nuts to the concave side of the perpendicular or edge of the inner side of the paddle, (or so near to the edge that the rolleru shall come to the edge of the paddle,) places being made in the paddles for the rollers; These places are made by cutting a T in the paddle and in turning the parts each side of the stem inward, (cutting out a part for the bar.) These will form cheeks to keep the rollers on the axles andin a true position and add strength to the paddles. The planes are to be made of wood, faced true with iron and fastened to frame of the vessel, above and below the drum,

in such a position that the paddle shall be fullyshifted at the center line. The planes will extend from a point 0 in the center line (distant the radius of the paddle-roller and of the axle-bar from and within the paddlecircle) to any point w desired in the inner paddle-circle. An arc of a circleP (or any other curve desired) may be substituted for the planes. The arc may be drawn on any radius less than that of the outer paddlecircle and greater than that of theI length of the chord of the arc, and the plane and arc may be combined. The planes and arcs may be so extended that the paddle may begin shifting when it has passed vhalf its distance which in the wheel described is iifteen de- The rollers are made of iron grecs.

are not necessary.

gradually and steadily sh itted by the planes or arcs than by the wheels or gangs, being capa- Ycaisson.

In these cases (planes, arcs, and curves) the roller-guide circle is carried round within the wheel-pit on a circle Z, drawn by a radius'from the center of the paddle-wheel to the apex 0 of the plane or arc, (the point where the paddle is fully shifted.) Vhether rthe guards are used or not, the roller-guide circles may commence at that apex, and be-l 'tween that and the side ot' the vessel will project inward from the guards or from the side of the vessel, in which case the receiving-rollers The paddles will be more ble of being more extended than the wheels and presentinga more even surface than the gangs and being more simple in construction than either; and the paddles may be fully shifted at any point n desired between the` center and transverselines. The guards Qare two segments of circles on a radius as much greater (0.4) than that of the outer paddle vcircle as shall afford room for the pillar 30 between them. They are made of timber or planlgof suf'icientthickness (0.4) for strength,

`banded on the outer edge by a thick (0.075)

bar of' iron, which is firmly secured to the guards, and bolted at each end to the side of ,the vessel. They are fitted and fastened to vthe vessel about an inch (0.1) above and below1 the line of the ends ot' the paddles. The lower vguards maybe constructed in the frame 3l of the vessel with such supports underneath as the construction of the vessel will permit.

The upper guard is supported at its outer edge by a strong iron pillar S0, placed in the out the guards, the sole object of which (if the caisson be not used) is to protect the paddles from injury by collision with external objects. The caisson R R2 is not necessary to the use of the wheel with or without the guards, but is added as aconvenience -for inclosing the paddles when the vessel is propelled by sails, and for making repairs, without taking it into dock or laying it down.

The guards forni a top and bottom for the The top guard must be strengthened in its fastenings to the vessel by iron knees passing under it and up on the sides p of the vessel and firmly bolted, so as to prevent the `possibility of collapse by pressure. The inner edges of the bands must be made level, and the outer side of the bands turned 'Ito a circle concentric wit-l1 the paddle-circle.

A grooveiscuton the inner side of the guards against the inside of the bands, of suticient depth and thickness (0.1) to receive the flange of the railway-rollers 38.

the pillar and the upperpguard. The cover- The caisson R R2 is A small space v(0.05) is left between the upper shoulder ot made in two sections of a circle concentric with the guard-circles, of timber or plank, closely fitted to, and of the depth (4.5) of the outside of the guards, and of suicient thickness A(0.5) to sustain the pressure ot' the water from without. The timber or planks of the caisson are halved at each edge, so as to make shoulders 32 to fit between the guards, and so that the inside of the halving shall fit to the edges ot' the guards. The length between the shoulders atV t-he ships side will be the distance between the guards, and at the pillar the distance from the top of the lower guard to the top ot' the upper shoulder ofthe pillar. The inclination is made on the upper edge of the section. The sections of the caisson R2, when at rest within the vessel, are placed in spaces U, fore and att the wheelpit, concentric with and about one foot without the paddle-circle, being a continuation of the circle of the sections, and ot their depth (4.5) and thickness (0.5,) (with a sufficient allowance to permit them to move frcely,) and of suicient length to permit their being put in and taken out within the vessel. The length of a section is the distance from its connection with the cog-wheels 34 to the'pillar 30. The bands of the guards are extended on the same circle within the wheel-pit to the length of the sections of the caisson, of which they are the railways 37 and guides. Two sections 33 of cast-iron, on a circle corresponding with the inside of the caisson, having cogs on 'the inner side, (extending from the cog-wheels as far as is necessary to move the caisson,) are attached to the inside of each section, about two inches (0.2) from their shoulders, leaving a suticient space between the cog-sections and the top ot the shoulders for the play of the guide-rollers. Two cogwheels St, fitted to mesh with the cog-sections, having a capstan or crank 35 on the upper end of the axle, are fixed on the same axle, and placed perpentlicularly within the vessel at as little distance from its Aside as will permit the working of the capstan or crank. Sets ot' rollers 36, two on an axle, are placed within the vessel so as to bear against each side of the caisson in t-he spaces between the cog-sections and shoulders. In the top and bottom of each section three flange-rollers 3S are titted (one near each end, the other in the middle) to run on the railways and in the grooves. The places on the bottom railway, under which the outer and middle rollers rest when the sections are (out) in place, are hollowed out, so as to bring the top of the upper shoulder at the pillar on a level with the shoulder of the pillar, (but so fitted as to have an easy rise when moving back.) The object of the wedge form of the sections is to ease their moving ont and to secure a water-tight joint on the shoulders, (as well as on the face of the hands) by the collapse of the guards. At the place where the caisson enters the vessel on each side the space (0.025) on the outside is left a little open. Against this opening a strip of thick rm leather y is tted at one edge to the side of the vessel and the other edge passes on to the caisson, against which (the caisson being in place and the Water being pumped out of the wheel pit) it is pressed by the external water, and a tight joint secured. The space between the Wheelpit and Ithe caisson maybe filled with timber or left open with the wheel-pit, as shall be best adapted to the strength ot' the Vessel. A pump Sis itted near the side of the Wheelpit, connected with'it, and also an air-tube T, to supply the wheel-pit With air when the pump is in operation, both rising above the water-line.

Vhen repairs are to be made, the sections of the caisson are. run outv upon the railways, and brought home against each other at the pillar, (being inclined and fitted atthe end to the form of pillar,) so as to secure a close joint. The water is then pumped out of the wheel-pit.. The pressure of the Water on the outside ofthe sect-ions brings them home upon the rims of the guards, While the pressure on the outside ot the guards will bring them home upon the pillar and upon the shoulders oE` the caisson. The coveringof the Wheelpit may then be taken oft' for the examination or repair ot' the Wheel; and When closed and the wheel-pit being again iilled with water, the sections of the caisson are run back to their places within the Vessel,

What I claim as my invention is- The meansand modes ot shifting and regulating the motion of the paddles, and the guards and caisson, as herein described, or by any variation of construct-ion that maybe deemed more convenient, on the same principles and to the same end; but in this application I claim nothing for the separate parts in the construction, excepting when used in the combination of, orin connection with, a horizontal shifting paddle-Wheel.

The advantages of the improvements described are a greater relative speed, (compared with Wheels of the same diameter and surface of paddles at the same number of revolutions per Ininute,) a greater security against external damage, and the practicability ot' being repaired Without being laid down or put into dock; and also, the inclosureot' the Vessel when propelled by sails, and then 'increasing its buoyancy by exhausting the wheel-pit.

HORACE EVERETT. Witnesses:

J AMES YOUNG, N. YOUNG.

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