the several figs. 7, 8, 9, 10, 11, and 12. Fig. 7, is an elevation of the engine; fig. 8, a section of the same, taken vertically through the cylinder to the slide valve and the air-pump; fig. 9, is a horizontal view of the top of the cylinder valve-box and air-pump of these improved engines; fig. 10, is a horizontal section, taken through the cylinder of a similar engine on the other side of the vessel; fig. 11, is a section, taken transversely through a steam vessel, shewing the positions in elevation of the two engines mentioned in the preceding figures,—the cylinder of one being in vertical section, the other an external view, taken upon a plane in advance of the former, with the crank, shaft, and paddle wheels; and fig. 12, is a horizontal view, as seen from above, of the two engines and their appendages.-The same letters of reference pointing out similar parts of the machinery in all the six last-mentioned figures.

The cylinders of large area are shewn at a, a,—and b, are their pistons. c, c, are two perpendicular rods inserted into each piston, and working through stuffing boxes in the lid of the cylinder. d, is a cross head, to which the two piston rods are keyed at top; and e, e, are the guide rods, fixed on cast-iron supports, upon which rods the cross head d, slides up and down. The connecting rod f, is attached above to the cross head, and below to the crank g, g, on the paddle shaft. The other parts of the engines will appear so obvious, from inspecting the drawings, as not to require further description.

It will be perceived that by this arrangement of the parts of the engine, motion is given to the crank shaft, below the cross head, by a single connecting rod.

The advantages resulting from this improvement, are, that a paddle shaft, placed at a given height from the bottom of the vessel, will be enabled to receive a longer stroke

of the piston than by any other arrangement now in use; a more compact and firm connection of the cylinder with the crank shaft bearings is effected, and a cylinder of much greater diameter may be applied, by which the principle of working steam expansively, may be more fully carried out, and a more direct action of the steam power on the crank obtained, with a less weight of materials and a greater economy of space than has heretofore been obtained by any of the arrangements of marine engines in use.

The third feature of our invention, viz., the method of adjusting the expansive valves of combined engines, will be seen by reference to Plate I., figs. 13, 14, 15, and 16.

In these figures, 13 represents the central portion of the double crank shaft of a steam vessel, with the parts appended, by which the above object is effected, as they would appear in elevation. Fig. 14, is a horizontal view of the same. Fig. 15, is an elevation taken at right angles to fig. 13, about the middle of the shaft, which is here shewn in section; and fig. 16, is an elevation also at right angles to fig. 13, shewing one of the cams upon the shaft in section, by which the lever and rod of the expansion valve is worked,—the respective letters referring to the same parts of the machinery in these last mentioned figures.

The central part of a double crank shaft is shewn at a, a, supposed to be adapted to a pair of engines. b, b, is a tube or socket, sliding horizontally upon the shaft, but prevented from turning upon it by a rib on the shaft taking into a long groove in the socket.

This tube or socket has two small snail cams c, and d, affixed to it or cast upon it, and in the centre, between the cams, a series of rings or flutes e, e, are also formed upon the tube. A spindle, placed at right angles to the main crank shaft, has a pinion f, the teeth of which take into the rings or plates e, e, (shewn also detached at fig. 15,)

and by turning this spindle and pinion ƒ, (which may be done by a hand wheel g,) the tube b, b, with its snail cams, will be slidden upon the main crank shaft, to the right or left, as may be required.

Upon the periphery of the snail cams c, and d, the antifriction rollers in the levers h, and i, are intended to work, (as shewn also in the detached fig. 16.) The rods from these levers h, and i, are connected to the expansion valves of the two engines below, and hence by the action of the cams c, and d, against the levers h and i, as the main shaft a, revolves, the expansion valves are opened and closed.

Let it be supposed, that by turning the pinion ƒ, the tube or socket b, b, (seen in figs. 13, and 14,) has been slidden toward the left, as far as it will go; then, as the main shaft revolves, the uninterrupted circular periphery of the cams c, and d, will act against the levers h, and i, so as to keep them in their elevated positions,-consequently the expansion valves will, under those circumstances, remain open. If however it is desirable to shut off the steam during a part of the rotation of the main shaft, we turn the pinion f, so as to slide the tube b, b, with the cams c and d, toward the right in fig. 13 and 14.

When this is done, only a portion of the circular periphery of each cam will be enabled to act in holding up the levers; for, as the main shaft with the cams revolve, the roller of each lever h, or i, will, when the snail or curved edge of the cam comes under the roller, allow the lever to fall, and by so doing to close the expansion valve, and shut off the steam from the working cylinder, until the roller rises again up the opposite edges of the snail, and gets on to the larger radius of the cam, when the lever will be raised, and the expansion valve opened, allowing a free passage to the steam.

In this way the cams may be slidden still farther to the

right, and cause so small a portion of the larger radius of the cams to act against the levers, as to shut off the steam during the greater part of the rotation of the main shaft.

By this apparatus we are enabled to regulate the flow of the steam into both engines at once, by one simple movement of the spindle and pinion, and without interrupting for a moment the working of the engines; such a means of adjustment being highly important in bringing into operation the full effect of steam, applied upon the expansive principle, in economising fuel, and adapting the power of engines to the varying circumstances at sea, between light and heavy lading, and between strong head wind and scudding before the gale.

The peculiar construction of main beams for supporting the crank shafts, mentioned in the fourth feature of our invention, are formed by combining long flat plates of rolled iron, which we unite to long bars of iron, turned up at right angles, or what is commonly called angle iron. The plates are firmly attached to these bars by rows of rivets, in the ordinary way of making wrought-iron boilers. Such beams may be extended to any length, and made into any form required, and applied as at m, m, m, in figs. 1, 2, 5, and 6; and the bearing and other parts of the engines may be attached to these beams, as shewn in the drawings. These beams may be made of unlimited strength, and with a comparatively small weight of material.-[Inrolled in the Rolls Chapel Office, November, 1839.]

Specification drawn by Messrs. Newton and Berry,

To GOLDSWORTHY GURNEY, of Bude, in the county of Cornwall, Esquire, and FREDERICK RIXON, of Cockspur-street, Pall Mall, in the county of Middlesex, for their invention of improvements in the apparatus for producing and distributing light.-[Sealed 8th June, 1839.]

THIS invention of improvements in the apparatus for producing and distributing light, is applicable to lamps or burners, wherein oil or oleaginous matters, in a liquid state, are the materials consumed for producing the illumination; and our improvements also apply to various kinds of lamps, burners, or lights, wherein the inflammable gas or vapour obtained by the distillation of coal, oil, resin, asphaltum, or other bituminous, resinous, or oleaginous matters is used, as the material for illumination; such gases or vapours being previously obtained, and then conveyed to the lamps or burners by pipes from a reservoir or gasometer; and consists, in the first place, in improved arrangements and constructions of conducting pipes or tubes and cocks, and jets or burners, whereby we are enabled to introduce into the interior of the flame of such lamps or burners, a stream or jet of pure oxygen gas. The atmosphere or atmospheric air being carefully excluded therefrom, that is, from passing through the burner, or into the interior of the flame. This jet or stream of pure oxygen is applied or given to the flame for the purpose of producing a more intense ignition of the carbonaceous matters, and consequently a more brilliant light than can be obtained where atmospheric air alone, or a mixture of atmospheric air and inflammable gases, are used to cause cumbustion.

It may be proper here to remark, that we are perfectly