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furnaces, as the nature of the metal requires more or less heat to fuse it.

Iron is melted either in a blast furnace or cupola, which is a small cylindric furnace blown by bellows or otherwise: and the metal and fuel are put in together at top; and when melted the metal is let out at bottom, and conveyed to the mould by a channel in the sand, if the work is large; or, if smaller, it is received into a ladle called a shank, shewn at X, in fig. 6. It has three handles, and is carried between two men, the double handles are very convenient for inclining the ladle to pour out the metal. It contains about an hundred weight; but for smaller quantities a single-handed ladle is employed. For very heavy castings the metal is fused in what is called a reverberating furnace acting by the flame of the fuel alone. Brass and the more valuable metals are melted in crucibles, heated either in the blast furnace or in the air furnace, which is described in our article BRASS FOUNDERY. As the cupola and reverberating furnaces are used in numerous other processes in the arts, besides foundery, we shall de scribe their construction under the article FURNACE. The sand moulds above described, by having two or more flasks one upon the other, and dividing the pattern into several parts, are applicable to a very large proportion of the articles which come before the founder: but it is here proper to make the distinction between wet and dry sand. The former is used where the intricacy of the pattern requires the sand to be wetted to give it sufficient adhesion, and preserve its figure. When a mould of this kind is finished, it must be dried in a stove to evaporate the water, before the casting. Dry sand is used for more simple patterns, and requires no more water than may be suffered to remain in the mould when cast without danger.

Loam is also a material used by founders for making their moulds, when they are required of such dimensions that the weight of so large a body of sand would be too great to support itself if rammed in flasks; also for others which are too complicated to be moulded in sand: the loam is clay well mixed up with water, which is moulded while in a soft state and afterwards dried. To explain the art of moulding in loam, we shall describe the manner of making a mould for a large hemispherical boiler; and the reader will easily perceive that a similar method is applicable to large bells, cylinders, cisterns, and many other articles. AA, fig. 8, pl. 74, represents the shape of the boiler which is to be cast, in an inverted state. The founder provides a round iron ring L, fig. 7, somewhat larger than the intended boiler; upon this ring he erects a dome of brick work BB, fig. 9, rather smaller than the inside of the boiler; when this is completed, an axis DD is erected,. turning on pivots at its ends. The socket for the lower pivot is fixed in a stake driven in the ground beneath the dome, and the upper pivot turns in a socket fixed to the beam EE, in the roof of the building. The axis DD has an arm F sliding upon it, which can be fixed at any height by a screw. To this arm a piece of board G is screwed ; and its internal edge cut out to the curve the intended boiler is to have, and with a notch in the lower part proper to fit to the ring a at the bottom. After this preparation the moulder spreads a layer of wet loam upon the dome of brick work; and by turning the board G, and its axis D round, the loam will be scraped round to its true figure. By this means, in a short time, a core is formed the proper size to shape the inside of the vessel; and it is dried

by making a fire beneath it. Another dome is now constructed in the same manuer, but the size and figure of the outside of the vessel: and upon this any rings, ornaments, &c. which are required, must be engraved. When dried, this dome must be painted over with a blacking made of charcoal ground up with water, and a good thickness of loam is spread upon it. Iron wire and old hoops are worked up in it, to give it the necessary strength. After drying this outer coat, the whole is turned over, and the bricks and loam of the first operation are removed; leaving a hollow shell, as the blacking prevents a connection of the two layers of loam. CCC, fig. 9, is a section of this shell, shewing the manner in which it is placed over the core BB, so as to leave the dark space for the reception of the metal, which is poured in through two or more holes at dd. The mould must be buried in a pit, and covered up with sand: long round sticks are set up in the holes dd, to keep the sand out of them: when drawn out they leave passages through the sand, down which the metal is conveyed to the mould. Iron rings R, fig. 6. are laid round the tops of the passages to prevent the metal breaking away the sand by its weight. The metal is always conveyed to such large moulds in channels cut out in the sand from the top hole of the furnace to the orifice of the mould.

A square cistern might be moulded in a similar manner by bricks and loam; and, with a reasonable share of ingenuity, a founder will be able to form a mould for any article he meets with.

FOUNDERY (Brass). The art of casting brass is a distinct business from iron foundery, though the manner of moulding any article to be cast in brass is the same as for iron; the difference lies in the manner of treating the metal in the furnace. Under our article BRASS will be found an extract from Dr. Rees'Cyclopedia, describing the process of making brass as practised in Flintshire; we are now enabled to lay before our reader drawings of the furnace used for this process at Mr. Bennet's brass works, Sheffield. The copper which is to be converted into brass is brought to the works in a granulated state, called shot copper, made by melting the copper and throwing it into cold water: 52 pounds of copper in this state are mixed with 80 pounds of calamine previously prepared by calci. nation, which is performed in a reverberating furnace three yards long, two yards wide, and the roof 18 inches high; the calamine being thrown into the furnace, and the flame of pit coal reverberated upon it from the roof of the furnace. In this manner it is exposed to a considerable heat for about four hours, the attendant continually stirring it about with an iron hoe, and turningitover, that every particle may be equally subjected to the action of the fire. By this operation the calamine is deprived of its sulphur, which passes off up the chimney, and is precipitated on the ground around the furnace in such quantities as to be a considerable annoyance to any inhabitants of its vicinity. The calamine loses in weight by the calcination: the large lumps of calamine are now broken by a hammer, and the whole ground to a fine powder between mill-stones like those used for grinding wheat; in this state the calamine is ready for making common brass. But for making the best brass which is to be rolled or drawn into wire, the calamine must be washed first before grinding. It is washed in a cistern called a buddle, about six feet square, and 12 inches deep. A small stream of clean water is brought on, on one side, and the waste flows out at the other. The calamine being thrown into this buddle, and well

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It is on the wax that the several mouldings and other ornaments and inscriptions, to be represent ed in relievo on the outside of the bell, are formed. The clapper or tongue is not properly a part of the bell, but is furnished from other hands. Europe it is usually of iron, with a large knob at the extremity; and is suspended in the middle of the bell. In China, it is only a huge wooden mallet, struck by force of arm against the bell; whence they can have but little of that consonancy so much admired in some of our rings of bells. The Chinese have an extraordinary way of increasing the sound of their bells; viz. by leaving a hole under the cannon; which our bell-founders rather reckon a defect.

The proportions of our bells differ very much from those of the Chinese. In ours, the modern proportions are, to make the diameter fifteen times the thickness of the brim, and the height twelve times. The parts of a bell are, 1. The sounding bow, terminated by an inferior circle, which grows thinner and thinner. 2. The brim, or that part of a bell whereon the clapper strikes, and which is thicker than the rest. S. The outward sinking of the middle of the bell, or the point under which it grows wider to the brim. 4. The waist or furniture, and the part that grows wider and thicker quite to the brim. 5. The upper vase, or that part which is above the waist. 6. The pallet which supports the staple of the clapper within. 7. The bent and hollowed branches of metal uniting with the cannons, to receive the iron keys, whereby the bell is hung up to the beam, which is its support and counterpoise, when rung out.

raked about, the water carries off a portion of calamine by which separation, the remainder is found to be greatly improved for the purpose of brass making. One bushel of pit-coal, ground to a fine powder, is now mixed up with 52 pounds of shot copper, and 82 of prepared calamine; the mixture is put in nine crucibles, one of which is shewn at fig. 4, Plate 75. The crucibles are now placed in the furnace, eight of them are ranged in a circle round the inside of the furnace as shewn at aaa in plan, fig. 1, and the ninth is placed in the center. The body of the furnace AA, fig. 1, 2, is nearly in the form of half an egg, that is, semi-spheroidal. The floor BB is an iron plate covered with clay and perforated with 12 small holes, denoted by dots in the plan, to bring up the supply of air. The top of the furnace has a round hole in it to introduce the crucibles and fuel, which is enclosed by a cover D, made of fine clay, with a small hole in the center. EE is the flue forming a communication from the top of the furnace to the chinney, to convey away the smoke, and cause a draught. The furnace is supplied with fresh air through the holes in the bottom of the furnace from a large draught arch FF, which communicated with the open air. After the crucibles are placed in the furnace, a small quantity of furzens is thrown down to prevent the 12 holes from being stopped up by the coals with which the furnace, is now filled. As it was heated red hot previous to being charged, the coals are quickly fired and the whole burns rapidly; the fire is continued for about twelve hours, the manager regulates its heat from his experience of former processes, and forms his judgment of the actual state of the furnace from the appearance and colour of the small stream of flame which issues from the stnall holed in the cover of the furnace mouth, when a damper at K in the flue E is closed so as to stop the current of air going up the chimney. He increases or diminishes the heat at pleasure, by opening or closing this damper, and thus regulating the draught. After the fire has been continued about 12 hours, the crucibles are taken out by the The method of forming the profile of a bell, pretongs fig. 5. which have curved jaws kh, to embrace vious to its being cast, in which the proportion of eoca crucible, and the contents of all the eight cru- the several parts may be seen, is as follows: The cibles poured into the centre one, from thence, it is thickness of the brim, C1 in Plate 76, is the run into ingot moulds, fig. 5, each of the ingots thus foundation of every other measure, and is divided formed will weigh about six pounds, and the whole into three equal parts. First, draw the line HD, quantity of brass produced by the operation is which represents the diameter of the bell; bisect about 80 pounds. The body of the furnace at AA it in F, and erect the perpendicular Ff; let DF is lined with fire-brick, and an iron ring is laid and HF be also bisected in E and G, and two other round the mouth, and upon which the eover shuts. perpendiculars Ee, Ga, be erected at E and G: The crucibles are made of Stourbridge clay, mix- GE will be the diameter of the top or upper vase, ed up with old glass melting-pots, first reduced to i. e. the diameter of the top will be half that of the a powder. An extensive brass work contains sev-bell; and it will therefore be the diameter of a eral furnaces which are arranged in two rows parallel to each other, and at snch a distance apart, that the flues of both rows may be carried up in the same stack of chimnies. Sometimes the brass is poured into moulds at once. Fig. 6 shews a pair of flasks, AA the upper, BB the lower; a the pius to put them together, bb the holes for the metal.

FOUNDERY OF BELLS. The metal, it is to be observed, is different for bells from what it is for statues, there being no tiu in the statue-metal: but there is a fifth, and sometimes more, in the bell-metal.

The dimensions of the core and the wax for bells, if a ring of bells especially, are not left to chance, but must be measured on a scale or diapason, which gives the height, aperture, and thickness, necessary for the several tones required.

The business of bell-foundery is reducible to three particulars. 1. The proportion of a bell. 2. The forming of the mould. And, 3. The melting of the metal. There are two kinds of proportious, viz. the simple and the relative; the former are those proportions only that are between the several parts of a bell to render it sonorous; the relative proportions establish a requisite harmony between several bells.

bell which will sound an octave to the other. Diyide the diameter of the bell, or the line HD, into fifteen (qual parts, and one of these will give C1 the thickness of the brim; divide again each of these fifteen equal parts into three other equal parts, and then form a scale. From this scale take twelve of the larger divisions or of the whole scale in the compass, aud, setting one leg in D, describe an arc to cut the line Ee in N; draw ND, and divide this line into twelve equal parts; at the point 1 erect the perpendicular 1C=10, and C1 will be the thickness of the brim of the diameter: draw the line CD: bisect DN; and at the point of bisection 6 erect the perpendicular 6K14 of the larger divisions on the scale. With an opening of the compass equal to twice the length of the scale or thirty brims, setting one leg in N, describe an are of a circle, and with the

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