Piercing-saw blades commonly measure from 3 to 5 inches long, and they are fixed in very light frames, such as fig. 714, which are from about 2 to 4 inches deep from the saw to the back; in some instances piercing-saws exceed the depth of 8 inches, as in m, fig. 716. The blades are fixed between small screw clamps, the inner sides of which are mostly cut like files. Sometimes, as in fig. 715, the clamp near the handle is extended as a wire through the handle, and is tightened by a nut at the extremity, somewhat as in a violin-bow; but in general the slide is considered sufficient and preferable, as when it is loosened the tension of the saw can be appreciated with the fingers, and retained with the thumb-screw.
Some kinds of silversmith's works are pierced with this instrument, and embellished with the graver. When the design is original, the engraving is usually first done, and the interstices are cut out with the saw. But for the convenience of repetition, recourse is had to brass pattern plates, pierced and engraved like the finished work; the brass pattern is laid on the work, and all its interstices are marked through with a fine scriber. In copying designs from any article of silver, the new piece is laid upon the original, the interstices of which are smoked through with a lamp: and in curvilinear works that cannot be pierced while straight, the pattern is dabbed with printing-ink, a paper is laid thereon, and rubbed on its upper surface with a burnisher; the paper thus printed is then pasted upon the object to be pierced. The under side of the original is printed from, to make the copy direct and not reversed.
The outline having been obtained by one of the above modes, a hole is made with the breast-drill in every piercing, and where practicable, the holes form the circular terminations of the apertures. The several curves are then followed with the saw, which is used vertically, and with the handle downwards, whilst the plate is held horizontally upon the pin of the jeweller's bench with the fingers, in order that both the work and the saw may be freely twisted about in sawing out the several parts.
The silver-piercer sits at the silversmith's and jeweller's ordinary work-bench, tunned like a round table, with four or six semicircular scollops, about 18 inches diameter around it; the pins, or small filing boards, are about 3 inches square, and project inwards into the bottoms of the bays or scollops, each of which has a skin or a leather bag nailed around its edge, that serves to collect the filings removed from the work.
This form of work-table is adopted, in order that a centra1 lamp may serve for the four or six workmen, each of whom has a glass globe 6 to 8 inches diameter, filled with water, to act as a condensing lens, and direct a strong light to the spot occupied by his work. Spirits of wine are added to the water, to prevent it from freezing and bursting the globe. The benches are frequently made semicircular, and placed against a window, as the circular bench requires a sky-light.
The amateur can employ in piercing, a small square filing-board with a fillet beneath, by which it is fixed horizontally in the ordinary vice. Should he prefer fixing the work, it may be still held horizontally, provided he employs a hand-vice, and pinches it by the half of its joint in the tail-vice, so as to place its jaws horizontally. In passing round the small curves, the strokes of the saw must be short, quick, and feeble; in the larger curves the full length of the blade may be more vigorously used.
Some of the very minute pierced works are drilled and then finished with small files, as in the plates formerly used for covering the balances of watches, but in general the file is not used. The piercing saw is also employed for cutting out small escutcheons and other pieces for inlaying.
From the pierced works, appear to have been derived those inlaid works, consisting of curved and flowing Hues, which are produced by a method that may be called counterpart-sawing, and in which two plates of differently coloured materials, whether wood, metal, ivory, tortoise, or pearl shell, are temporarily fixed together, and then cut through at the same time with a fine hair-like saw. By this process the removed pieces so exactly correspond in form with the respective perforations, that when the two colours are separated and interchanged, the one material forms the ground, the other the inlay or pattern, and vice versa: and the pieces fit so nearly together, that the route of the saw is only visible as a fine line on close inspection.
These works receive the general name of inlaid or marquetry works; and also the specific names of buhl-works and reisner-works, from their respective inventors.*
The saws used in piercing and inlaying scarcely differ but in size: thus, the black line m, in fig. 716, is drawn from a large piercing saw of metal, and the dotted line w, from an ordinary buhl-saw of wood: the former measures eight inches from the blade to the frame, the latter twelve or sometimes twenty inches, to avoid the angles of large works. The wooden frames are made of three pieces of wood, halved and glued together to constitute the three sides of a rectangle, after which two pieces are glued upon each side, each at the angle of 45 degrees across the corners: the whole, when thoroughly dry, is cut round to the form represented. The screws for giving tension to the blade, although commonly added, are seldom used, as the frame is only sprung together at the moment of fixing the saw, and by its reaction stiffens the blade.
The buhl-cutter sits astride a horse, or a long narrow stool, fig. 717, having near the one extremity two vertical jaws lined with brass at the top: the one jaw is fixed, the other is notched
* The term marquetry seems to be employed to designate all kinds of inlaid work, known in France as marqueterie en bois, and marqueterie en metal. It includes not only the works of counterpart sawing, in which flowers, animals, landscapes, and other objects are represented in their proper tints, by inlaying and without the aid of the artist's pencil; but it also includes those geometrical patterns composed of angular pieces, laid down in succession more after the manner of ordinary veneering: and amongst which, the specimens of parquetage, or inlaid floors, appear to claim a place.
Boule work, and reisner work, are considered by the virtuosi to apply exclusively to the works of two celebrated ebenistes of those names, both settled in France; the former, an Italian, in the reign of Louis XIV., the latter, a German, in the time of Louis XIV. to XV. Their cabinet works were as much celebrated for their graceful forms or outlines, as for their embellishment with inlaying.
Boule, mostly employed dark-coloured tortoise-shell inlaid with brass, in flowing patterns, occasionally ornamented with the graver. Reisner, used principally as the ground tulip-wood (called in France bois de rose,) inlaid with flowers in dark woods, grouped in a much less crowded manner than in ordinary marquetry. Reisner occasionally combined therewith bands and margins, in which the woods were contrasted as to the direction of the grain, as well as colour.
The terms buhl or boot work appear to bo corrupted from boule, and now refer to any two materials of contrasted colours inlaid with the saw, and which, in France, would be called by the general name of marqueterie.