FORGE properly signifies a little furnace, furnished with a pair of bellows to render the combustion more vivid ; and employed by smiths and other artisans in iron, steel, &c. to heat their metals, in order to soften and render them more manageable upon the anvil. In laboratories there is generally a small furnace, consisting of a cylindrical piece, open at top, which has at its lower end a hole for receiving the nozle of a pair of double bellows. This kind of forge is very convenient for fusions, as the operation is quickly performed, and with few coals. The natives of Ceylon work with considerable skill and taste in gold and silver; and, with means that appear very inadequate, execute articles of jewellery that would certainly be admired, but not very easily imitated in this country. The best artists require only the following apparatus and tools, a low earthen pot, full of chaff or saw dust, in which he makes a little charcoal fire; a small bamboo blow-pipe, with which he excites the fire ; a short earthen tube or nozle, the extremity of which is placed at the bottom of the fire, and through which the artist directs the blast of the blowpipe; two or three small crucibles made of the fine clay of ant-hills, a pair of tongs, an anvil, two or three small hammers, and a file ; and to conclude the list, a few small bars of iron or brass, about two inches long, and differently pointed for different kinds of work.
It is astonishing what an intense little fire, more than sufficiently strong to melt gold and silver, can be kindled in a few minutes. Such a simple forge deserves to be better known ; it is, perhaps, even deserving the attention of the scien tific experimenter, and may be useful to him when he wishes to excite a small fire larger than can be produced by the common blow-pipe, and he has not a forge at command. The success of this little forge depends a good deal in the bed of the fire being composed of a combustible material, and a very bad conductor of heat. The blacksmiths of Ceylon are not behind their brethren, the jewellers, in the simplicity of their apparatus, however inferior they may be in skill.
The cut in the next page represents two smiths at a forge. The bellows consist of a couple of bags made of bullocks' hides, each furnished with a bamboo nozle, and a long slit as a mouth, with wooden lips, that are opened and drawn up and shut and pressed down alternately by the hands of the person sitting between the pair, who keeps up a constant blast by the alternate action of the two. The nozle of the bellows is introduced through a small hole in the foot of the screen, which constitutes the back of the forge, and serves to allow the ascent of the smoke. It is composed of a mat or hurdle, supported between two sticks, and plastered over with clay to protect it from the heat. Mr. J. Sperne,
of Belper, near Derby, has invented a forge, principally designed for the manu facture of nails, which is highly deserving of notice. It is peculiarly adapted for the burning of charcoal ; and the inventor proposes to adopt this fuel in conjunction with coke, or coal purified from sulphur, generally in the proportion of three parts of the latter to one of the former ; these proportions to be, how ever, varied according to the nature of the coal, and the quality of the metal to be wrought. This forge is constructed as follows :--the brickwork is first carried up from the bottom of a cylindrical figure, to the height of twenty-four inches, leaving proper apertures for the delivery of the ashes, the reception of the water troughs, and for the insertion of the nozle of the bellows; the circular aperture in the centre is then covered with a fine cast-iron grating, which forms the bottom of the furnace. The courses of brick-work are next carried up a foot higher, and the whole is then surmounted by a cast-iron plate, with a rim or border six inches high round the external periphery, forming a convenient dish for holding the fuel to replenish the fire. In the centre of the cast-iron top plate is an aperture corresponding with the fire-place, and to this aperture is fitted a cast-iron ring, supporting, on three cast-iron pillars, another ring which carries the brick-work of the chimney, which is cylindrical. The bellows are suspended from a frame, and are worked by a lever which encircles the chimney, affording every workman employed the convenience of acting upon it with facility ; and as this construction of the forge will admit of six workpeople being employed round it in making of nails, the fire is always kept up bright and vivid by the continual blasts from the bellows. With respect to the advantages of the forge the inventor observes—"By the peculiar construction of the fire-place, wood charcoal alone may be used, which cannot be done in other forges ; but by a mixture of wood charcoal with coke for fuel, the metals to be wrought will acquire a surprising degree of malleability, and weld with great ease ; their tenacity and clearness will also be improved, and they will have, when cold, a better face or skin than can be put upon them by any other method. In addition to the great advantage of apportioning the fuel to the work required, the circular form will admit of a greater number of workmen being employed at the same time at this forge than at any other, thereby causing a saving of brickwork in the erection of forges, of bellows, and ahoproom for working them, and a permanent saving in the fuel for their consumption. See IRON.