Supposing the object to be veneered to be a large surface--a number of panels, or the top of a table of ebony, for instance--the substance of the table may be Honduras mahogany. The wood has been carefully seasoned, and the top grooved, tongued, and firmly glued up to the required form. The ebony surface is also carefully fitted together and glued on paper, the surface being left rough, so that the glue may have a firm hold on the fibre of the grain. A corresponding roughness is produced on the upper surface of the mahogany, which is then laid on the metal bed. Glue, perfectly fluid and hot, is now rapidly brushed over the entire surface, and the thin veneer top is laid upon it, and firmly pressed down by several workmen, who then carefully go over the whole with hammers having broad, flat heads; the object of this being to flatten any apparent thicknesses of glue or bubbles of air which would interfere with the perfect contact of the two surfaces of wood. The whole is then placed under a caul or frame that touches it all over, and a number of strong bars are screwed down till the greater part of the glue has been pressed out. The complete union of the surfaces of the woods is effected not so much by the quantity of glue as by the absolute exclusion of the air, and this can only be done by pressure. The whole metal bed or frame in which the veneering is performed is heated by steam, or by gas-burners, where steam cannot be applied. The wood is left for twenty-four or thirty hours, till the glue has been completely set and hardened. The caul or frame is then removed, the paper used to keep the thin veneer together before gluing is scraped off, and the work of finishing and French polishing takes place. French polish, or careful wax polish, has the effect of keeping out air and damp, which latter might soften the glue and disintegrate the surface veneer. It is to be observed, that such wood as the finest French or Italian walnut is often veneered on mahogany, for it lasts better in this condition than if it was solid; large surfaces and thicknesses of walnut being difficult to procure without faults. Walnut veneers are applied in greater thicknesses than ebony; and if the surfaces to which they are applied are curved, cauls, or shaped pieces of wood made to fit them, are screwed down and held by numerous wooden vices, as in the method already described.