In the earlier work of Boule the inlay was produced at great cost, owing to the waste of valuable material in cutting; and the shell is left of its natural colour; in later work the manufacture was more economical. Two or three thicknesses of the different material were glued or stuck together and sawn through at one operation. An equal number of figures and of matrices or hollow pieces exactly corresponding were thus produced, and by counter-charging two or more designs were obtained by the same sawing. These are technically known as "boule and counter," the brass forming the groundwork and the pattern alternately. In the later or "new boule," the shell is laid on a gilt ground or on vermilion. The brass is elaborately chased with a graver. Besides these plates of brass for marquetry ornaments, Boule, who was a sculptor of no mean pretensions, founded and chased up feet, edgings, bracket supports, &c., to his work in relief, or in the round, also in brass. The original use of these parts was to protect the edges and angles, and bind the thin inlaid work together where it was interrupted by angles in the structure. Afterwards brass mounts, more or less relieved, were added to enrich the flat designs of the surfaces. Classical altars, engraved or chased as mere surface decoration, would receive the addition of claw feet actually relieved. Figures standing on such altars, pedestals, &c., were made in relief more or less bold. In this way Boule's later work is not only a brilliant and rich piece of surface decoration, but its metallic parts are repoussé or embossed with thicknesses of metal ornament. In boule work all parts of the marquetry are held down by glue to the bed, usually of oak. The metal is occasionally fastened down by small brass pins or nails, which are hammered flat and chased over so as to be imperceptible. [Illustration]