1 gine more efficient, by keeping it perfectly tight. I, the common condenser; and necessary pump, which is wrought by studds or stops projecting from the horizontal shaft, or any other simple and effectual way the engineer may think proper, as is more distinctly seen in Fig. 3, which is the end view of the shafts, and the side view of the piston rods; the operation of which is so obvious, as not to require elucidation. Fig. 2 exhibits the birds eye view of Fig. 1, with the top of the cylinder and compressing rings removed, to shew the operation or apparatus for opening and closing the pallets, gates, &c. and also part of the flanches removed to shew the situation of the valves. The letters of reference in this case, Fig. 2, are placed upon similar or the same parts of the engine as in Fig. 1, which it would be superfluous to recapitulate. C C, the pallets, &c. formed of two or more pieces of metal; one part of the said pallet is permanently secured to each cylinder A and B, whilst the other part or parts turn on a joint or hinge; which said joint or hinge is made steam-tight or secured, together with the whole of the edges coming into contact with the cylinders, with a hemp cloth stuffed, wadded, or folded together, or by other similar materials, capable of stopping the passage of steam, and which must be screwed or otherwise fastened on the front of the said pallet; and by the pressure of the steam it is pressed or brought in contact with the said pallet and cylinders, and thus it effectually prevents the escape of steam, or other fluids by or with which the engine is wrought. KK, two racks and pinions communicating by a straight and parallel bar, working through a stuffing box in the sides of each cylinder, whereby the said valves are opened and shut, whilst passing each other, from the external part of the engine by a piece projecting from the upper or lower part of the 1 fixed cylinder, which may be placed at the option of the engineer; which said piece in its passage comes into contact with the gear connected with the said pallets, and thereby with any of the well-known simple methods or gear used for opening and shutting of valves in the present steam engines. The gates, &c. of the engine are opened and shut as occasion requires. L, Fig. 2, exhibits a second gate, &c. which in this case slides backward against a straight parallel surface during the time the pallet in the revolving cylinder is passing when the said gate is sliding by the gear against the revolving cylinder, as in the drawing. The said gates may be opened and closed in a variety of ways, such as a spindle ground into the bottom of the fixed cylinder, and connected by a link to the gate internally, or a crank or compound lever may be applied instead of the rack and pinion externally. Neither of those plans or methods form any part of my Patent, as being well understood by the engineers; but I rest my claim upon the use and application of the gates and pallets or cocks, as applied to the steam-engine in the manner specified. Fig. 4 exhibits the vertical section of a different plan for producing the same or similar effects as in Fig. 1 and 2 previously explained, by causing the pallets, slides, &c. to be lifted from below the bottom of the cylinder; in this case, I always prefer making the cylinder shallow and wide, in order that the gates and slides may have but as little space as possible to slide or move through, whilst in Fig. 1, I prefer the keeping the cylinder deep and narrow, in order that the gates, valves, &c. may be quickly opened and shut. Fig. 4, A, the outside stationary cylinder. B the inner cylinder. C, the top of the cylinder and rings, as in Figs. 1 and 2, already explained. D, plate of metal, as represented by the dotted lines, made very straight, smooth, smooth, and parallel, as it respects its thickness. E, a small shaft or axle, working through a stuffing box on each end, and connected at the centre to the extremity of the said plate inside a box, or a receptacle fixed on the outside of the cylinder A, allowing room sufficient for the said plate to drop clear off the bottom of the cylinder, whilst an accurate incision is made in the bottom and side of the cylinder sufficient to admit the said plate D to slide freely up and down, which is effected by a rack and pinion, or lever, or any other simple contrivance attached or connected to the extremity of the shaft E; by which means the steam is caused to act on the same or a similar principle as in Fig. 1 previously explained. F, Fig. 4, presents a second way of producing the same effect, namely, that of raising a plate of metal through an incision made in the bottom of the cylinder A, `from a box fixed underneath the cylinder, through the medium of a parallel bar working through through a stuffing box, whereby the said plate D is raised or depressed, as the working of the engine requires. Fig. 6, is the side view of the apparatus necessary for raising and depressing the said plate D, by the working of the engine. H, a lever or arm, fixed to the revolving cylinder. I, the connecting rods with a weight at the lower extremity, equal to raise the said plate D; thus, as soon as the lever H comes in contact with the lower connecting rod or lever I, the weight on the extremity is thereby lifted, and the plate D is depressed, and thereby the fixed pallet on the moving cylinder is allowed to pass; but, as soon as the lever H has passed the lever I, the weight on the end of the said lever I raises the plate D into the cylinder that fills up the place when the steam is admitted between the plate D, and the pallet secured to the revolving cylinder; and so on vice versa. Fig. 5 is the bird's eye view of Fig. 4, with the same general letters of reference to their respective parts, as in Fig. 4. K, steam passage. L, passage leading or communicating with the condenser, when the steam is required to be condensed. Here it may be necessary to remark, to prevent infringements, that, although I have shewn the plate.D as rising upwards, as being the most convenient way; nevertheless, the boxes necessary to receive the plates may be placed above the cylinder, and the plates be made to rise in them, or the plates may be raised in an oblique instead of perpendicular direction. Fig. 7 is the vertical section of my farther-improved rotary engine. A, the outside fixed cylinder. B, the inner or revolving cylinder. C, compressing ring, similar to Fig. 1. DD, two or more pallets, working through a deep stuffing-box, and by a lever or levers, racks, wheels, &c. are from the external part of the engine turned alternately flat or edgewise in one side of the said Fig. 7, they are fixed to the lower part of the stationary cylinder, and are those seen flatwise, &c. the passage stopped; in the other side, the said pallets Dare fixed to the revolving cylinder, and are seen on their edges, with the passages open. E, steam passage. F, passage to the condenser. Fig. 9 presents a view of the pallets, and part of the cylinder and stuffing-boxes, on a large scale. Fig. 8 is the bird's eye view of Fig. 7, with the same letters of reference, as corresponding in similar parts in Fig. 7, previously explained in that figure. The cylinder top or lid is removed, and two sets of valves are shewn; the first DD are shut, and ready for the action of the steam, the other said pallets are shewn on their edges, preparatory to their passing each other; during which time the steam VOL. XI.-SECOND SERIES. A a valve valve is to be shut, which is performed by gear as in the common steam-engine, and which will be varied at the option of the engineer. Fig. 10 is the bird's eye view of my rotary engine as wrought with a cock or portion of a circle, whereby a similar effect is produced as in Fig. 1, by or with a portion of circles: in these figures 10, 11, 12, the lids of the cylinders are removed, and a part of the flanches where the circles or irregular cocks are used is broken off, to render the working parts clear and conspicuous. In these figures, the stationary parts are shadowed light, and the moveable parts dark *. A, the outer or fixed cylinder. B, inner or revolving cylinder. CC, the pallet, cock, or portion of a circle, fitted accurately into the circle it prescribes; with a spindle working through the top of the cylinder, as in Fig. 7. D, the groove as is shadowed red, into or against which the part coming into contact with the revolving cylinder is secured with a piece of hardened metal, in order that the constant friction of the revolving cylinder shall not injure the pallet or cock. E the passage to the boiler. F, the passage to the condenser. G, the pallet secured to the working cylinder. In this figure two portions of circles and cocks are introduced, for the purpose of shewing clearly their situations in different places, the same as in Figs. 11 and 12. Fig. 11 is the bird's eye view of an engine in most respects similar to Fig. 10. A, the fixed cylinder. B, the inner or revolving cylinder. C C, two pallets or portions of circles turning on the axis secured to the revolving cylinder, into which they turn as passing the fixed or stationary plate D, which is fixed on its edge, and occasionally pressed into contact with the revolving cylinder, The shading and colouring afterwards mentioned, have been necessarily omitted in the plate, by |