engine; fig. 3, a horizontal section of the cylinders; and fig. 4, a transverse vertical elevation and section, representing two engines, disposed side by side, for combined action, in the manner engines usually are combined on board steam vessels, one of the engines being represented in section, the other in elevation. a, a, is the steam-cylinder, its interior surface being bored truly cylindrical, as usual, for steam-cylinders; and b, b, is a small cylinder, fixed concentrically within the steam-cylinder a, a;—the external cylindrical surface of the small cylinder is turned true in a lathe, but the interior of the small cylinder does not require boring. n, n, is the bottom of the steam-cylinder, to which the flange, around the lower part of the steam-cylinder a, a, is fitted, as usual, with a close joint; and the small cylinder b, b, is also fitted to the same bottom, with an internal flange at its lower end, so as to be truly concentric with the interior of the cylinder a, a, in order that an annular cylindrical space may be left between the two cylinders, of exactly equal breadth all round; m, m, is the cylinder-cover, made so as to leave the small cylinder b, open, and is bolted to the exterior flange around the top of the cylinder; c, c, is the annular piston, fitted into the cylindrical space between the two cylinders; d, d, are two piston-rods, passing through stuffing-boxes, and are fixed to the annular piston, at two points, as shewn in figs. 1 and 3. The upper ends of these rods are securely fastened to the upper extremities of a T-shaped cross-head e, e, f,f, composed of two parallel sides, united together at the extremities of the upper horizontal part, and also united at the lower extremity of the upright stem f,f, by the joint-pin s, at the lower end of the connecting-rod g; a space sufficient being left between these extremities to allow the connecting-rod g, to work therein, as shewn in figs. 2, 3, and 4.

The upper end of the connecting-rod g, is fitted with a similar joint, upon the crank-pin of the crank h, in the usual manner; p, p, (figs. 1 and 3,) are the two sliding pieces, at the lower ends of the upright stems f, f.-These sliding pieces are fastened to both the stems f, f, as shewn in fig. 3, and form, as it were, a sort of box, within which the joint, at the lower end of the connecting-rod g, is enclosed, but without touching the interior of such box.

The two sliding pieces p, p, move up and down in angular grooves, formed in the two upright edges r, r, fixed withinside of the interior of the small cylinder b, b, at opposite sides of the circumference of that interior, so as to constitute a parallel vertical guiding groove.

The two ends of the joint-pin 8, are reduced to small joint-pins, which project out on each side, beyond the sides f, of the T-shaped cross-head; and on these pins are fitted the lower ends of two links j,j, for working the air-pump, their upper ends being united to the long ends of two levers k, k, situated one on each side of the cross-head e, e; and from the opposite or short ends of these levers, the rod l, of the air-pump z, is suspended by two suitable links, both of which are jointed thereto. The fulcrum t, of the levers k, k, is common to both levers, and is sustained by suitable framing.

The horizontal axes i, i, i, of the cranks h, are the same as usual in marine steam-engines. The several bearings for the axes are sustained in one horizontal line, in a framing of iron, affixed between two parallel wooden beams, extending, horizontally, across the vessel, from side to side thereof; and the iron framing is upheld by four upright props of wrought-iron, firmly attached to the base, whereon the cylinder a, a, stands.

This base is made to serve for the condenser, being continued out from beneath the cylinder, in order to admit the

THE

London

JOURNAL AND REPERTORY

OF

Arts, Sciences, and Manufactures.

CONJOINED SERIES.

No. CXXII.

Recent Patents.

TO JOSEPH MAUDSLAY, of Lambeth, in the county of Surrey, engineer, for an improvement in the arrangement and combination of certain parts of steam-engines, to be used for steam navigation.—[Sealed 16th March, 1841.]

THIS improvement relates to the arrangement and combination of certain parts of steam-engines, of that kind or class whereof the centre of the steam-cylinder (wherein the piston works) is situated immediately beneath the rotative axis of the crank. And the particular parts of steamengines, to which the arrangement and combination relates, are the steam-cylinder, with its bottom and cover, the piston and piston-rod, the cross-head belonging to the pistonrod, and the connecting-rod,—together with all requisite appurtenances to the several parts.

In Plate I., several views of the improved construction of engine are shewn; fig. 1, being a longitudinal vertical section; fig. 2, a horizontal plan of the upper part of the

VOL. XX.

B

engine; fig. 3, a horizontal section of the cylinders; and fig. 4, a transverse vertical elevation and section, representing two engines, disposed side by side, for combined action, in the manner engines usually are combined on board steam vessels,-one of the engines being represented in section, the other in elevation. a, a, is the steam-cylinder, its interior surface being bored truly cylindrical, as usual, for steam-cylinders; and b, b, is a small cylinder, fixed concentrically within the steam-cylinder a, a;-the external cylindrical surface of the small cylinder is turned true in a lathe, but the interior of the small cylinder does not require boring. n, n, is the bottom of the steam-cylinder, to which the flange, around the lower part of the steam-cylinder a, a, is fitted, as usual, with a close joint; and the small cylinder b, b, is also fitted to the same bottom, with an internal flange at its lower end, so as to be truly concentric with the interior of the cylinder a, a, in order that an annular cylindrical space may be left between the two cylinders, of exactly equal breadth all round; m, m, is the cylinder-cover, made so as to leave the small cylinder b, open, and is bolted to the exterior flange around the top of the cylinder; c, c, is the annular piston, fitted into the cylindrical space between the two cylinders; d, d, are two piston-rods, passing through stuffing-boxes, and are fixed to the annular piston, at two points, as shewn in figs. 1 and 3. The upper ends of these rods are securely fastened to the upper extremities of a T-shaped cross-head e, e, f,f, composed of two parallel sides, united together at the extremities of the upper horizontal part, and also united at the lower extremity of the upright stem f,f, by the joint-pin s, at the lower end of the connecting-rod g; a space sufficient being left between these extremities to allow the connecting-rod g, to work therein, as shewn in figs. 2, 3, and 4.