when affixed to the axle of a winding barrel, and acted upon by the toothed lever.

The patentee claims, Firstly,—The peculiar construction of lever described, having teeth or indentations at its end, and an elongated slot or eye to receive the fulcrum-bolt or axle, upon which the lever shall work; which elongated slot or eye may be curved, and will answer best if of a bean or kidney shape, allowing the lever to act upon the rackwheel or chain, in one direction, and to pass over free in the opposite direction.

Secondly,―The boxes or frames for the lever and slide or chain to work in, with the appendages, represented in the drawing.

Thirdly,―The sliding rack-bar, or the toothed wheel, or chain, in connection with the lever, as described, for drawing up to tension the shrouds of a vessel, or for winding a chain or rope upon a barrel, or for raising or moving heavy weights. [Inrolled at the Petty Bag Office, June, 1841.] Specification drawn by Messrs. Newton and Berry.

TO JOHN WHITE, of Haddington, North Britain, ironmonger, for his invention of certain improvements in the construction of ovens and heated air stoves.—[Sealed 27th September, 1838.]

THE principal feature of this invention, is lining the iron surfaces of the ovens and stoves with fire-clay, for the purpose of enabling their surfaces to retain heat for a considerable length of time, and to give it off slowly and uniformly.

The ovens are formed by double plates of iron, at about half an inch a part; the faces between which, are to be

filled with fire-clay, for the purpose of retaining a uniform heat. No particular shape of oven is claimed.

In Plate II., is a representation of one of the portable stoves, in vertical section. a, is the fire-box, of a cylindrical form, made of fire-brick, which is encompassed by a cylindrical casing of plate iron. An aperture is made at b, for the introduction of fuel, which is to be coke; c, is the grate or fire-bars. The chimney is at d, and e, is a damper, hung within to regulate the draft up the chimney; and on the top is a plate f, covered with a bed of sand, to prevent the escape of smoke or effluvia. On the outside of this stove is a casing g, g, surrounding the stove, at a few inches distant; and between the two, zigzag partitions of plate iron are placed, in order to conduct cold air from the bottom round the ash-pit; which air, as it passes up the zigzag channels, becomes heated, and escapes from the chamber h, at top, through an adjustable regulator i.

The particular novelty in this stove, is lining it with fireclay, formed in one cylindrical piece, which totally prevents the escape of vapour from the fire, and so long retains the heat, that it will be gradually and uniformly given off, to warm the passing current of air, for many hours, without attention from servants.

Some other constructions of air stoves, are proposed,-as those formed with horizontal tubes, through which the flame and heated vapour from a furnace are conducted. These tubes are to be coated on the outside with fire-clay, in order that the atmospheric air, in passing over and around them, may abstract heat from the earthy surface, instead of coming in contact with the iron.

The precise form of stove, exhibited in the drawing, is not claimed, but merely the fire-clay coating, for the purpose of economising fuel, by concentrating and retaining the heat, and giving it off, uniformly, at a comparatively

low temperature; so that the air, heated by such apparatus, shall be pure and uninjured by contact with surfaces of heated iron. [Inrolled in the Inrolment Office, March, 1839.]

TO ANDRE KURTZ, of Liverpool, manufacturing chemist, for a certain improvement or improvements in the construction of furnaces.-[Sealed 5th November, 1840.]

THESE improvements in the construction of furnaces, consist in a certain novel and peculiar arrangement of the fire-bars upon which the fuel is to be placed; and also in an improved arrangement or application of certain air passages, chambers, or flues, to be used in combination with the improved grate, and, together, composing the furnace.

The principal object of the improvements, is to effect the consumption of smoke, and consequently an economy of fuel, by preventing the smoke and other gaseous productions of combustion ascending the flue or chimney. This is effected partly by means of the peculiar positions of the grate-bars in the furnace, and also by the particular arrangement and construction of the air chambers or passages, by which heated air is conveyed into the furnace, at the required temperature, and at different parts of the furnace, when it impinges immediately upon the smoke or unconsumed combustible matter, all over the fire-bed upon the grate, by means of an unlimited number of apertures on each side of the furnace, and in front of the fire-bridge of the furnace, which occasions the smoke or gaseous product to be burned.

The principle of the improvements will be readily understood by reference to Plate I., where two distinct

constructions of furnaces are represented, -the one as applied to the ordinary waggon boiler, and the other to the tubular boiler of a stationary steam-engine. Fig. 1, represents an external end elevation of the boiler and furnace; fig. 2, a transverse sectional view of the same; fig. 3, a plan or horizontal view of the walls of the furnace and air passages, with the boiler and upper courses of brickwork removed; and fig. 4, is a view taken in isometrical perspective, through the same, one of the outer walls being removed. This construction of furnace, consists of two separate fire chambers or compartments, formed by the side walls a, b, c, and the grate and fire-bars d, e, f.

It will be seen in fig. 4, that each grate or fire-place consists of three distinct and separate sets or series of firebars;—those marked d, inclining, obliquely, downwards from the entrance or fire-door towards the bridge;—those marked 7, lying perfectly horizontal; and those marked ƒ, inclining, obliquely, upwards from thence towards the bridge, thus forming a hollow fire-bed or grate, having a sufficient depth or substance in the middle for the ordinary heating purposes of the furnace, which may be suitably accommodated by modifying the length of the bars e, e, and also having a thinner layer of heated coal, gradually diminishing towards the bridge, and approaching towards the bottom of the boiler, to assist the combustion of the smoke, by means of the air passing between the fire-bars and chared coals, at that point just below the bridge.

The series of fire-bars d, e, f, are all supported by transverse hollow bearers g, g, let into the side and middle walls of the furnace a, b, c, and communicating with the air passages or chambers h, h, formed in the brick-work or walls of the furnace; these hollow bearers g, g, and the chambers or passages h, h, are all in continuous connection with each other, opening into the furnace or fire-places at

the apertures i, i. The hollow bearers g, g, are open to the ash-pit, by having an aperture formed underneath at j; and, by being in connection with the passages h, h, also communicate with the apertures i, i, in the furnace.

It will be observed, that the passages h, h, must be closed from the external atmosphere by shutting the doors h*, h*, which are only opened occasionally to clean the flues. Now, the fire-doors k, k, being closed, and the ashpit 1, 7, being partially closed, (having only a slight opening left at the bottom for the requisite supply of air,) the air will rush into the hollow bearers g, g, and also into the passages h, h, in the furnace walls, and, being greatly heated by the action of the fire, will disperse itself through the passages or chambers g, and h, and rushing into the furnace through the several apertures i, i, will immediately impinge upon the unconsumed combustible matter above the fire-bed, in an unlimited number of streams or currents, so that the smoke and other gaseous products, will be effectually consumed, instead of passing away to the flue or chimney. If any portion of smoke, yet unconsumed, passes off, a further extension of the hot air passages may be made, by connecting the hollow bearers g, g, with side passages, leading to a further air chamber or passage, constructed in the bridge of the furnace, and opening the whole width of the bridge, at the top of the furnace.

Another construction of furnace is represented at figs. 4, and 5. Fig. 4, being a transverse section, and fig. 5, a longitudinal section of an improved furnace, as adapted to a tubular boiler. In these figures, the principal features of the improvements are applied, as in the furnace just described, and all the same parts are marked with corresponding letters of reference. The bridge m, m, is divided, having a passage n, for the heated air, constructed in it, and opening into the furnace the whole width of the

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