in a general sense, signifies an original pattern, proposed for any one to copy or imitate.

This word is particularly used, in building, to signify an artificial pattern in wood, stone, plaster, or other matter, of some intended structure, with all its parts and proportions; being intended to give an idea of the effect it will have in its proper dimensions, and to serve as a guide in its execution. In all great buildings, it is much the surest way to make a model in relief, and not to trust to a bare design or draught. Models are also used for the building of ships, and for many other purposes.

In academies for painting and sculpture, the term model is given to a naked figure disposed in any particular posture, to assist the artist while executing a figure in a similar attitude.

Models in imitation of any natural or artificial substance are most usually made by means of moulds composed of plaster of Paris. The particular manner of making models, or casts, as they are also called, depends on the form of the subject to be taken. The process is easy where the parts are elevated only in a slight degree, or where they form only a right or obtuse angle with the principal surface from which they project; but where the parts project in smaller angles, or form curves inclined towards the principal surface, the work becomes more difficult. Bodies that are soft, however, may often be freed from the mould, even although they possess the latter shape. When a model is to be taken, the surface of the original is first to be greased, in order to prevent the plaster from sticking to it; but if the substance itself be slippery, as is the case with the internal parts of the human body, this need not be done. When necessary, it may be covered over with linseed oil by means of a painter's brush. The original is then to be placed on a smooth table, previously greased or covered with a cloth, to prevent the plaster from sticking to it; then the original is surrounded with a frame or ridge of glaziers' putty, at such a distance from it as will admit the plaster to rest upon the table on all sides of the subject for about an inch, or as much as is sufficient to give the proper degree of strength to the mould. The liquid plaster is then to be poured as uniformly as possible over the whole substance, until it is everywhere covered to such a thickness as the requisite strength of the mould, increasing with the size, may require. The whole must then be suffered to remain in this condition until the plaster has attained its hardness. When the frame is taken away, the mould may be inverted, and the subject removed from it; and when the plaster is thoroughly dry, let it be well seasoned. The mould being thus formed and seasoned, it must next be prepared for the cast by greasing the inside of it with a mixture of olive oil and lard in equal parts. It may now be filled to the brim with fine fluid plaster, and the thickness further increased by the addition of coarse plaster, to form a strong basis or support for the cast where this support is requisite, as is particularly the case where the thin and membranous parts of the body are to be represented. After the plaster is poured into the mould, it must be suffered to stand until it has acquired the greatest degree of hardness it will receive, after which the mould must be removed; but this will be attended with some difficulty when the shape of the subject is unfavourable, and in some cases the mould must be separated by means of a small mallet and chisel. If by these instruments any parts of the model should be broken off, they may be cemented by making the two surfaces to be applied to each other quite wet, interposing betwixt them a little liquid plaster, and then smoothing the joint after being thoroughly dry. Any small holes which may be made in the mould can be filled up with liquid plaster, after the sides have been thoroughly wetted, and smoothed over with the edge of a knife. In many cases it is altogether impracticable to prepare a mould of one piece for a whole subject; and therefore it must be considered how this can be effected in such a manner as to divide the mould into the fewest pieces. This may be done by making every piece cover as much of the pattern as possible, without surrounding such projecting parts, or running into such hollows, as would not admit a separation of the mould. To make a mould upon a hard and dry substance, the surface must in the first place be rubbed smoothly over with the mixture of oil and lard above mentioned. Such hollows as require internal pieces are then to be filled up with fluid plaster, and whilst it continues in this state, a wire loop must be introduced into it, by which, when hardened, it can be pulled off.

After the mould is completely formed, it requires to be dried either naturally or by a gentle artificial heat, and then seasoned. This being done, nothing more is requisite to form the model than to pour into it the finest liquid plaster of Paris. After a layer of this, about half an inch in thickness, has been formed all round the mould, the coarser kind may be used to fill it up entirely, or to give to the model the thickness required. Besides the models which are taken from inanimate bodies, casts of the living face are frequently made, and this art has been brought to great perfection.

The method of making models in plaster of Paris is undoubtedly the easiest way of obtaining them. When models, however, are made of large objects, they must be constructed by the hand with some soft substance, as wax, clay, putty, &c.; and it being necessary to keep all the proportions mathematically exact, the construction of a single cast of this kind is a work of great labour and expense.