Mena's Stove.—This apparatus, for which Lieut. Maw obtained a patent in 1831, consists in the introduction of a fuel drawer, or receptacle for the fuel, which is placed under a grate of the usual construction, in order that the most volatile portion of the fuel may be liberated and be consumed in its ascent through the fire ; and when the coal has thus, by parting with its gaseous matter, been converted into coke, it is to be removed from the fuel receptacle, and placed upon the fire, leaving the receptacle at liberty for the introduction of another supply of fresh fuel. A front elevation of one of Lieut. Maw's fire grates is exhibited in the above cut at Frig. 1, and a sectional side view, lig. 2, wherein a shows a grate of the usual construction, and b a fuel drawer or receptacle, having a grating underneath, for the admission of atmospheric air to maintain the combustion. The openings in the grating between the fire and the fuel receptacle are made at some distance from the front, that the volatile matter, in its ascent, may not pass so near the front of the fire as to be cooled, lest it escape without being consumed. The advantages which would result from having the fuel supplied to a fire under the ignited portion, have been long acknowledged ; and of the various plans that have been proposed, we do not think there is one so well calculated to answer the purpose of burning the smoke as that of Lieut. Maw.
Witty's Fire Places. -- Mr. Witty, by a judicious attention to proportions, and the conveniences required, has succeeded in adapting the original invention of Watt (described under the word FURNACE,) to domestic stoves, particularly those of the close kind. Mr. Witty has, however, unadvisedly taken out a patent for these stoves, although we can discover nothing that is original in the principle nor in the arrangement of the parts. Some elegant and very effective stoves on this plan may be seen at the Museum of National Manufactures and the Mechanic Arts, in Leicester-square.
Notts Patent Furnaces.—A very effective kind of close stove, particularly adapted to large rooms, halls, and churches, and possessing considerable novelty of appearance, has lately been introduced into this country by Mr. J. B. Nott, from the United States. In the upper part of a low is a large capacious chamber, capable of holding a sufficient supply of coals for the days consumption ; from this receptacle the coals gradually sink down, as they are consumed, in front of the grate, and are deposited upon an arched grating, supported upon a pivot, upon which it is made to oscillate, (by using the poker as a lever for that purpose,) and thereby clear the bars of ashes ; and when it may be necessary to clear or put out the fire entirely, the said vibrating grating is moved through a greater angle, by which all the ignited fuel thereon is thrown out at either end of the arch. To give the lively appearance of an open fire, and the security of a close stove, the front of the stove is enclosed by windows of talc, through which the glowing fuel is seen. The air is admitted
for lighting the fire by leaving the ash-pit drawer a little way open, and when ignition is complete, the drawer may be entirely shut, as sufficient air finds its way through the imperfect junctions or fittings of the metal, to preserve a vivid combustion of the fuel. The fire chamber is encased in fire brick, or some other suitable slow conductor, which prevents the surrounding cast iron from obtaining that high temperature which is found to deteriorate the air of the apartment, and the heat is in consequence more uniformly diffused over the other parts of the structure, which presents altogether a very extensive surface of metal for the radiation of heat, principally derived from a tall ornamented chimney, of a flat pyramidal or pilaster-like form. In this chimney there is a turn valve, to regulate the egress of air, the action of which, together with the management of the ingress crevice at the ash-pit drawer, determines the quantity of heat or the rate of combustion of the fuel. In fitting a stove of this kind to a room having the ordinary cavity for the fire-place, Mr. Nett converts the latter into a hot air chamber, and places his close stove upon the hearth in front. A stove of this kind is employed for warming the extensive range of rooms at the Museum of National Manufactures and the Mechanic Arts, in Leicester-square, which it does most efficiently, with at economy of fuel. Anthracite, or stone coal, which is almost wholly free f bituminous matter, and emits, in consequence, scarcely any smoke, may be very advan tageously burned in stoves of this kind.
German, Pyramidal, Pedestal, Sarcophagus, 4-c. Stones.—All grates of this class are, strictly speaking, close stoves, the fire being entirely shut up within them, the flue or chimney usually consisting of a metallic pipe, which is con ducted through the walls of the room to the external atmosphere. The German stove is a vertical cylinder of sheet iron, mounted upon legs, having internally, and about midway, a short cylinder of cast iron, with a grating at bottom, which constitutes the fire room, and underneath is the ash pit. The tops, which are variously formed to suit particular purposes, are made to take on and off, so as to allow of baths, boilers, or retorts, to fill up the aperture, and thus become the cover to the upper part of the furnace ; the application of heat is thus very convenient and effective, and is much used for chemical processes, and manufacturing operations on the small scale. The pyramidal, pedestal, and sarcophagus stoves are of similar internal construction to the German or cylinder stoves, but they are usually of cast iron, and designed with a view to ornament as well as utility : their external forms are explained by their names.