There are two principles whereby artistic bronzes may be produced. The one is that known as "piece moulding," and is identically the same as that employed in making castings for. machinery, etc. Continental artists and founders call it moulage a la Frangaise, it having been brought to great perfection in France, where, indeed, it is supposed to have had its origin. The other process is that known as "Cera Perduta," or waste wax process. It is the more ancient of the two, and has been practised from time immemorial by the artists and artizans of Italy. Both methods have been, and are, successfully employed for the production of works of the greatest size.
There are reasons why an artist should sometimes prefer one method and sometimes another. When a piece of sculpture is to be produced on a very large scale, it is usual for the artist to make not only a careful sketch, but also a model, usually about life size; and on this model he will bestow all his skill and art; taking into account the distance at which the colossal work will have to be viewed, its height above the level of the spectator, the effect of the atmosphere in diminishing its apparent bulk, and in distorting its lines, the influence of any surrounding objects, and more especially the varying effects of light and shade. When this model has been carefully completed, the work is then reproduced in all its details on the large scale. One pair of hands will not suffice for the production of so large a work, and several assistants are usually employed, under the supervision and control of the master, who, working with them, is thus able to produce what is practically an exact enlargement of his smaller model.
Works on a colossal scale cannot be produced by the eye alone, but must be the result of scientific procedure. The forms are so large that the workman cannot see the effect of what he is doing. If he has to descend from a scaffold 10-12 ft. high, and go perhaps 50-60 ft. off, before he can get a comprehensive view, it is not likely that he will be able to correct any error which his eye may have discovered, because by the time he has again ascended the scaffold he can no longer recognise the exact spot that required alteration.
In these large works, anything like individuality of touch is at a discount, surface modelling is practically useless, and artistic effect is alone realised by the rhythm of line, the harmony of proportion, by the skilful arrangement of masses of shadow, and by the true relation of each plane to the rest of the work. If this is achieved, the result will be an artistic success, not to be enhanced by any amount of delicate manipulation, which would be entirely lost at the distance required for a comprehensive view of the work. It is, therefore, wise in the artist to select that method of casting which, while it faithfully reproduces these essential qualities, affords the least chance of mishap, and the greater facility for retrieving disaster.
The artist who enters on the production of a very colossal work is in the position of a general opening a campaign. He forms bis plan and lays down broadly the lines on which he intends to proceed: but he cannot foresee all the chances of war, nor the varying incidents which may oblige him to modify his plans if he would attain the reward of his labours.
Thus it is clear that for such works there is no system of founding so good as that which gives most scope to the founder, even if it were at the sacrifice of a very small degree of sharpness in • the castings.
With regard to small works, however, the case is very different, and exactly in proportion as these are small does the importance of delicate touch and surface modelling increase; not that the other qualities are diminished in value, for they are just as important as ever; but merely from the fact that the eye of the spectator is able to take in on the small scale that which it was nnable to appreciate on the large. Many persons who are unaccustomed to look at sculpture intelligently, and who think that art means pictures alone, would be surprised to learn that there was any difference between the touch of one sculptor and the handling of another. For such persons a work is finished in proportion as' its surface presents a polished uniformity. This idea is fostered by the miserable cabinet bronzes which are turned out wholesale by certain manufacturers, and are termed "art bronzes." These are often copies of fine originals, but most of their value is lost from the fact that they are cast in many pieces, which are then joined together, filed, and chased up in a happy-go-lucky commercial style by a not over skilful artisan. Thus every trace of the original hand is obliterated, all that remains is the design, and even with that liberties are often taken.
The turn of a head, the movement of an arm, are often varied according to the convenience or ignorance of the fitter.
The object of casting statues in bronze by piece moulding is to diminish the risk by facilitating the process. It is obviously easier to cast a part than the whole of a statue. This is the principle which underlies commercial castings. As an example take a figure representing Divine Wisdom, standing on a tortoise surrounded by waves, and supported by a branch of coral. The first operation of the founder is to cut off the head and arms of the plaster model, and the coral branch at its side. These are carefully replaced, being fitted with what are known as Roman or box joints, which, if properly made, ensure in the most effectual manner that the various parts shall not be misplaced.
The plaster model thus becomes a compound of five separate parts, fitted accurately one to the other. This makes the work of the founder much more easy and rapid. To mould and cast the head, the arms, and coral branch, each by itself, is so simple an operation that almost any lad in the foundry could be entrusted with it; but to cast the statue all in one piece would entail some rather complicated piece moulding. When denuded of its head, arms, and coral branch, the trunk it also a comparatively simple object to mould, though there is in the folds of the drapery a great deal of piece moulding which requires care and skill. The process briefly is as follows: - The trunk of the figure is laid in an iron box or flask of suitable size, and loosely packed in with the loam used by bronze founders. The figure being only about half imbedded in this loam, the surface of which is carefully pressed and smoothed all around the model, the latter presents somewhat the appearance of a bas-relief. The loam back-ground is then lightly and evenly powdered over with parting-dust, lycopodinm being much used for this purpose on the Continent. The object of this is to prevent one portion of the mould from adhering to another.