In the preceding chapter, we have seen that a knowledge of the methods of obtaining the precious metals, and of fabricating them into a variety of utensils, obtained from the remotest antiquity. We now come to describe some of the processes by means of which the modern manufactures of plate are carried on. As, how. ever, the production of a beautiful and endless class of wares, of which the body is copper, with only a superficial covering of silver, forms a most important branch of our home and export trade, and as the details of working these metals are much the same in respect to each kind, we shall describe them together, first preparing the way by briefly noticing the old-fashioned mode of " silvering," and giving some account of that vastly superior modern composition which, from the place of its earliest manufacture, has often been called " Sheffield plate."
The art of overlaying, for economy's sake, one metal with another more valuable, is of great antiquity, and was practised both with silver and gold; but the application of the more precious material upon the inferior one, appears, so far as we can judge, always to have been by some method analogous to washing or gilding, or by affixing sheets and foils in some less adhesive manner. Articles so gilt or silvered were from an early period objects of merchandise in this country, and are sometimes noticed in our statutes. In 1403, temp. Hen. IV. an act was passed to prevent deception in putting off gilt or plated locks, rings, beads, candlesticks, harness for girdles, chalices, sword pummels, powder boxes, &c. for solid metal; all such workmanship upon copper or latten being prohibited, except ornaments for the church, of which some part was to be left uncovered, to show the copper or brass.
The methods practised in later times, as well upon the Continent as in this country, for silvering copper or brass, were generally those depending upon amalgamation, and what is called French plating. In the former case, pure silver is dissolved in aquafortis, and precipitated with common salt; after which, it is mixed with about six times its weight of sal-ammoniac, sandaver, white vitriol, and a little sublimate: these ingredients are ground into a paste upon a smooth stone with a muller. With this preparation the article to be silvered is rubbed over, and afterwards exposed to a sufficient degree of heat to cause the silver to run, at which instant it must be taken from the fire, and dipped into diluted spirit of salt to clean it. By some such process, it is probable, many of the old metal clock faces were silvered. In the latter case,– French plating, – the practice is to make the metal very clean, and then heat it, until nearly red-hot, when leaf silver is laid on and immediately burnished down, the heat and friction causing it to adhere perfectly. By this method, successive layers of silver may he applied, to any thickness the work may require. Copper is very readily silvered in a superficial manner, by the following process, which is very analogous to the above, with the exception of the application of heat:–Two parts of silver-powder precipitated from a nitric solution of common salt; one part of alum and two parts of cream of tartar: these ingredients are made into a sort of paste with a little water. After cleaning the copper thoroughly, this paste is rubbed upon it by means of the finger covered with soft leather or fine muslin. When the piece is sufficiently whitened, it may be polished by the application of a buff, powdered with calcined hartshorn, or a little Spanish white. In some places it is very common to silver, by means of this preparation, the engraved breast-plates for coffins, the effect of which is very good; and although by no means durable, yet for this purpose the polish will last as long as the occasion for which its appearance is required.
One fact appears indisputable; namely, that by whatever process the old workmen covered copper with silver or gold, the precious metal was always laid on after the articles were formed, and never in such a way as to allow of the laminating, soldering, drawing, and otherwise perfectly working of the combined metals in one substance, as is practised in the manufacture of modern plated articles. An incidental allusion made by Mr. Jacob, though, probably, referring mainly to the old operations of silvering above adverted to, is calculated to convey the notion that the art of plating with silver upon copper, as now practised, originated in the metropolis; or at least, that it was first carried on there to any great extent as a business. "The introduction of plating with silver on copper," he says, " and especially since the manufacture has been removed from London to Birmingham and Sheffield, has caused a vastly increased consumption of silver, especially from about the year 1780, to the present time.'' The following respectable authority gives the discovery to the last named town, to which indeed, it justly belongs:–" The year 1742 is memorable in the history of Sheffield," says Mr. Hunter in his " Hallamshire," " for the introduction of a new manufacture, which has become a formidable rival to the ancient and staple manufactures of the neighbourhood, or, rather, an effective auxiliary in advancing the town of Sheffield to the rank it now holds among the commercial towns of this great empire. It was in that year that Mr. Thomas Bolsover, an ingenious mechanic, when employed to repair the handle of a knife which was composed partly of silver and partly of copper, was struck with the possibility of uniting the two metals, so as to form a cheap substance which should present only an exterior of silver, and which might, therefore, be used in the manufacture of various articles in which silver had been solely employed. He began a manufacture of articles made of this material, but confined himself to buttons, snuffboxes, and other light and small wares. Like many other first inventors,- he probably did not see the full value of his discovery, and it was reserved for another member of the corporation of cutlers of Sheffield, Mr. Joseph Hancock, to show to what other uses the copper plated in this new method might be applied, and how successfully it was possible to imitate the finest and most richly embossed plate. He employed it in the manufacture of candlesticks, teapots, waiters, and most of the old decorations of the sideboard, which, previously to his time, had been formed of wrought silver. The importance of the discovery now began to be fully understood; various companies were formed; workmen were easily procured from among the ingenious mechanics of Sheffield, while the streams in the neighbourhood furnished opportunities of erecting mills for rolling out the metals. Birmingham early obtained a share in this lucrative manufacture; but the honour of the invention belongs to Sheffield, as it is supposed to stand unrivalled in the extent to which the manufacture is carried, and the elegance and durability of its productions."
The name of one of the individuals mentioned above is associated with an affecting incident. Every reader of English local history has heard of Eyam, in the high peak of Derbyshire, as the village to which the plague was communicated from London in the dreadful year 1666. Among the melancholy memorials of its ravages which strangers usually visit, are several dilapidated grave-stones on a heathy hill a short distance from the village, and amongst them one ruined tomb sacred to the memory of a whole family of the name of Hancock, who, with the exception of one boy, fell victims to the pestilence. The " sad survivor of his fallen house" came to Sheffield, and to him we are indebted for giving the first impetus to a trade arising out of the art of plating on silver. Mr. Rhodes, indeed, in his elegant descriptive work entitled " Peak Scenery," directly attributes to Hancock the discovery of the art itself, though apparently on no sufficient authority: the claim of Mr. Bolsover to having first used it in making buttons, seems to be well founded, and family tradition still points to an old building called "Tudor-House," in one of the garrets of which the cunning loricator prepared in secrecy his metal for the rollers. Mr. Hunter intimates, that the first race of workmen were drawn from the other trades: they were for the most part coppersmiths, and of course well acquainted with the modes of working a material not altered in reality by the circumstance of being overlaid with a precious metal, though requiring many new conditions of skill in its management: their immediate successors earned very large wages, and many of them maintained a respectability of appearance, and took places in society which their descendants have not in every instance neglected to improve. The silversmiths of Sheffield long considered themselves a superior class of workmen, and a generous respect subsisted between them and their employers. Competition and other causes have greatly reduced though they have not even yet quite obliterated these honourable distinctions.
The following is the method of preparing the metal for the flatting mill:–Apiece of copper, somewhat in the form of a brick, and generally about 12 inches long, 3 inches wide, and 1 1/2 inch thick, is prepared either by cutting it from a bar of that substance of fine copper, or by casting it in an ingot mould as an alloy of about two pounds of brass to twelve pounds of copper. The mass, in either case, is trimmed into a neat form, by filing off the fash or any roughness which might appear; after which it is well and exactly filed on one of its sides with a rasp until it is bright and level, care being taken not to allow any particle of dirt to get upon it, nor even to touch it with the fingers so as to tarnish it. When it has been thus cleaned, a plate of silver, a little less than the surface of the copper, after being made perfectly flat, is scraped with a tool until quite clean on one side, particular care being taken not to soil it with the fingers. This plate, which is of a substance, in proportion to the copper, corresponding to the amount of silver which the sheet of metal is intended ultimately to bear, varies generally from the thickness of a half crown to that of two penny pieces: it is laid upon the piece of copper, so that the bright surfaces of the metals are in contact. Over the silver is placed a piece of sheet-iron, of the same size, brushed over with whiting to prevent its adherence to the mass when heated. The three substances, thus arranged, are well secured by means of small iron binding wire, wrapped round at intervals of an inch, and tightened by twisting with pliers. A little borax ground with water is laid around the silver in the space where its edge approaches that of the copper, after which it is ready for the fire.
A small reverberatory furnace, or low fire-brick oven, heated with hard clean coke, is used by the plater. When the coke is in a state of steady ignition, and the low roof of the oven entirely red-hot, the prepared metal is introduced upon the prongs of a sort of fire fork, and placed upon the cokes in the bottom. The door in front is then closed, and the draught increased, until the mass becomes red-hot: in a short time afterwards, the edges of the silver, where the borax was laid, and where it acts as a flux, exhibit a slight degree of fusion, the whole of the superficial plate being nearly in the same state. The ingot must now, by the introduction underneath it of the iron fork above mentioned, be carefully withdrawn, and laid aside to cool. Upon an exact attention to this operation the chief success of the plater depends; for if the metal be not removed almost immediately after the indication of fusion appears at the edges of the silver, it will presently run off into the fire; and if the removal of it, on the other hand, take place a little too soon, the two surfaces will be only partially united, and the work, of course, be good for nothing. But when taken from the fire at that point of temperature which experience indicates, the parts of the materials in contact are found to be in a state of the most perfect incorporation, so that no subsequent operation, however violent, can separate them.
It has already been observed that, although pure copper is mostly used, a metal slightly alloyed with brass is sometimes required: in the former state it is indispensable that fine silver alone be used, whereas, upon the alloy, silver of standard fineness will serve the purpose. This latter mixture is employed, among other purposes, in those cases where a tubular article has to be considerably expanded at the mouth by means of the lathe, an operation to which pure copper will rarely submit without fracture. In 1831, Mr. Roberts of Sheffield obtained a patent for a method of interposing between the two metals a layer of white copper or German silver, of a considerable thickness, the advantage of which in the wear of plated articles so manufactured must appear obvious; it is, however, too hard to admit of being wrought between silver and copper in the ordinary way to any useful extent. Plated metal is reduced into sheets by passing it between steel rollers in the usual way, taking care to heat or anneal it in the intervals of rolling. If designed for waiters, plateaux, or other articles requiring great breadth, it is rolled both ways, until it is spread out to the proper size; but if only for ordinary purposes, it is generally left narrow in proportion to its length. When the ingot is of about the size previously mentioned, it will be found that the copper will be overspread by the silver to within a little space of the edges; but if the silver be very thick in proportion to the copper, it will be found, in consequence of its greater ductility to spread beyond the inferior material. In the interlaminated metal above mentioned, owing to the hardness of the middle substance, the copper as well as the silver rolls over it on either side, and thus spoils the effect: when the ordinary plating is properly managed, the adhesion of the two metals is rarely found to be injured by any degree of lamination, though there are sometimes little risings or strippings on the surface. The weighing, cutting out, and distributing the metal to the workmen is generally confided to a responsible servant, whose knowledge of the details of every branch of the manufacture enables him to effect the objects of his employers with economy and precision.
The operations carried on in the manufactory of the plate-worker may be distributed into six or seven departments, which are more or less distinct as the establishment is large or otherwise:–1. Die-sinking; 2. Stamping; 3. Pierce-working; 4. Braziering; 5. Candlestick making; 6. Chasing and embossing: to these may be added, 7- Burnishing.
Die-cutting is a most important affair in the manufacture of plate; and it is that upon which the success and celebrity of many modern works depend. It is, at the same time, the most expensive branch of the business; so much so, indeed, as to place the production of the various articles which are usually exhibited in the showrooms of respectable houses quite beyond the reach of ordinary competition. The dies of the silversmith, as well as those of the brass stamper, are required to be made for the most part of steel; and at the same time they must be executed in a much finer manner. As, however, the metal is often very thin, and always soft, the dies are rarely hardened; notwithstanding which, they will last a very long time. The method of cutting steel dies has been described in a preceding chapter. Some few of them used in the manufacture of large dishes and covers, will serve when of cast metal; there being in the articles no sharp work to strike up: but when the designs are deep and delicate, the dies must be of the most exquisitely finished description; for while ornaments in brass, or even in silver, if stamped in a coarse die, might be generally got up by brushing, at the expense of a certain part of their sharpness, to this loss in the plated article would have to be added the risk of exposing the copper. In stamping, when the material is very thin, or the figure deep, particular care, and the frequent repetition of gentle blows, are required, especially at the beginning. The safety of the article during stamping is likewise greatly increased by placing it between two pieces of copper of the same substance; these forces, as they are called, are, along with the'matters being stamped, repeatedly lighted over a charcoal fire; and sometimes, when the plate is strong, it is stamped in a red-hot state. Some notion of the expense incurred in dies may be acquired from the fact, that sets for a candlestick which sells for about three guineas the pair, often cost upwards of 50/.; and if the candlestick have branches, from seventy to one hundred guineas. Nor is there even in the latter case a separate die for every part; as it will be obvious to any person looking at the finished article, that many of the embossed portions of a branched candlestick are duplicates. The parts are, however, more numerous than would be supposed; and an ordinary plated bed candlestick, with extinguisher, is often made up of more than twenty pieces. It must not, however, be supposed, that the dies, even for expensive articles, are always paid for on terms like these: there is a shallow, showy kind of work, calculated to impose upon the unpractised, the expense of which hears no proportion to that which is produced from dies of the best workmen.
Ancient candelabra were made of gold, or silver, or bronze. In Cicero we have an account of a candelabrum for the temple of Jupiter Capitolinus at Rome, of vast magnitude, executed by the first artists, and profusely adorned with gems. The general form was that of a column, the top varying in breadth, as it was intended for a brazier or a lamp. Cicero asserts that there was hardly a house in Sicily, in his time, without candelabra of silver. Tarentum, and the isle of Aegina, according to Pliny, were considered by the Romans as the most celebrated manufactories of candelabra, and, as we may infer, of other like articles. Those made at the former place were esteemed for the elegance of their external form, and those of the latter for their finished workmanship. Pliny reproaches an opulent Roman lady with having given 50,000 sesterces for a candelabrum, which was the joint production of these celebrated manufactories.
It will be obvious that a good deal of the comparative success of a plate establishment must depend upon the taste and spirit employed in the dies; and as fashions are constantly fluctuating, it is the object of the principal to obtain and retain as much originality as possible in this department. A new article or ornament, however, no sooner makes its appearance in the market in silver, than it is copied by the plater, and from the latter by the Britannia metal worker; and there have not been wanting instances in which much less honourable artifices have been resorted to in order to obtain' facsimiles of patterns, even before publication by the original deviser,–the very nature of a die rendering it the most convenient thing in the world to copy almost in an instant.
Pierce-working is that branch of the business which relates to the fabrication of articles, the body part of which has been perforated with punches at the fly-press. This style of work, which, for inkstands, snuffer trays, waiters, and baskets, was at one time very fashionable, is at present little in demand.
The brazier is the artificer who, in a general sense, undertakes the work which requires to be fashioned or perfected by hammering and hard soldering; his art is analogous to that of the coppersmith. He is required to be conversant with all the methods of planishing, not flat pieces, but of tubular, swaged, and bellied work of every description. These operations are among the most ingenious of the trade; indeed, the dexterity with which a practised workman uses his hammer is astonishing. The polished steel head upon which plate is planished is called a stake, and may either have a flat face like an anvil, or be of a columnar or globular form, and bent so as to suit the swelling out and driving in of the parts of teapots, basins, urns, or other articles. These, and many similar productions, are shaped in the first place by means of wooden mallets; spherical wares being also bulged out in part by placing them on a sand bag, and striking with a hammer upon an iron instrument placed inside. Silver and plated articles, after having been a good deal hammered, require to be lighted by being heated red-hot: with the latter substance this operation demands to be performed with great nicety; for if it be not sufficiently heated, it will remain as hard as it was before exposure to the fire; if, on the other hand, it should be exposed but a moment too long to the glowing cinders, the silver will fly off the copper; hence, the workmen have taught themselves by experience to judge of the temperature of the metal by the following simple hut infallible criterion: – They first black the article all over in the smoke of a lamp, and then holding it over a clear fire of cokes, mark when the fuliginous film burns off; as, at that time, and not before, the proper degree of annealing has taken place.
The planishing hammer for flat work has two round polished steel faces; one slightly convex, and the other flat; the former used in the earlier stage of the work. It will readily be conceived that great care is required in planishing, not only that the strokes be made exactly level to the work, but that they be so distributed and combined as ultimately to present one uniform and even surface, and not a series of indentations. In the earlier era of the manufacture, this end was effected by the application of a vast number of slight strokes with a light hammer, as was practised by the coppersmith; it was afterwards found, that by wrapping a piece of woollen stuff over the face of the large hammer, the marks of the rough planishing were much more easily assimilated: a thin piece of bright copper was subsequently added with increased good effect; and, lastly, a bit of hard polished sheet steel was tied over the hammer's face, a piece of moreen or some such stuff being interposed between them. The advantages derived from this simple contrivance, as to saving of time and perfection of workmanship, are exceedingly great to the silversmith.
The parallel swells in most circular vessels, and the raised edges of salvers, with a variety of regular mouldings, are usually produced by means of swages, in the manner described under tin-plate working. In raising silver, however, and especially plated metal, the face of the swage, as well as the under part, requires to be covered with sheet tin to prevent the instrument from marking the metal at every stroke of the hammer, an evil which is still farther avoided by bringing a weighted cord over the upper swage, to keep it from rebounding when struck. Although there are few forms into which an expert hammerman cannot mould such tractable metals as silver and copper, and the facility with which others may be stamped will be apparent, yet, as the former method is exceedingly expensive, on account of the time consumed, and the latter in the article of dies, the application of steam power is, in some large concerns, made to supersede to a considerable extent both methods, by what is termed spinning, a process exactly similar to that described by the same appellation in the Britannia metal manufacture. The operation consists in causing a circular piece of sheet metal to revolve in contact with a model chuck of wood or other substance, upon which it is gently and progressively folded down and moulded by means of appropriately formed burnishers.
Should any accident occur to lay bare the copper in any particular spot, or should the working up by the hammer of any latent blister in the metal produce a similar deformity, the workman has a most ingenious remedy, in what is called French plating. Having scraped or scoured the place quite clean, and perhaps matted or roughed it a little with a tool, he places upon it a piece of silver reduced to the thinness of foil, and well cleaned: holding the article over a charcoal fire, and directing the heat to the part to he mended, he suffers it to become just red-hot, upon which he instantly applies a burnisher to the patch, and rubs it for a few minutes, when it will be found to adhere so completely that no subsequent operation of hammering or otherwise will remove it. These foils may be laid upon each other to any thickness; and in fact, certain portions of the surface of almost every description of plated ware intended to be engraved, are so overlaid, and the silver afterwards beaten down into the substance of the body.
The candlestick maker has nothing to do with planishing, but he has more occasion for the lathe than any other member of the trade, as he uses a variety of tubes, screws, and slides or springs. Candlesticks are often made with a double pillar, so as to admit of being drawn out in the manner of a telescope, an arrangement of great convenience in their use, as they may thereby be elevated or lowered at pleasure. The tubes are formed in the manner already described in the chapter on lacquered brass-work: they are soldered with a composition consisting of silver alloyed with brass, and reduced to the state of filings. It is laid on by means of a pencil inside the tube, upon a line of triturated borax, as in copper brazing, but in silver plate soldering it is necessary to mix a little sandaver with the borax, to prevent the solder from taking to the iron wire with which the work is wrapped, and which, but for this precaution, would, when stripped away, not only tear the plating off the copper, but be liable to pull even a silver tube into holes. The greatest care is likewise required in soldering tubes or other things of plated metal over a fire where bellows are used; for if the article be not removed on the instant the solder melts, the silver is burnt off, and the naked copper appears; or, as the workmen significantly say, "Alexander shows his face." Accidents like this do not admit of being remedied by the French plating process, described before. The screws used in the slide candlesticks, and for other purposes by the silvermiths, are of brass, over the faces or other outward portions of which a coating of the metal is ingeniously folded at the lathe, by means of tools similar to those used in spinning. By the lastnamed operation, the nozzle or top of the candlestick is generally formed; the foot, or bottom, if merely round, oval or oblong, is stamped, and is indebted for its perfection to the beauty and goodness of the die. The raised work, consisting of foliages, flowers, scrolls, and all the alto-relievo figures which silver and plated articles exhibit, is mostly stamped in sections, out of metal sufficiently thin to receive an exquisitely sharp impression from the die; these ornaments, after having been filled with soft solder to give them solidity, are attached by means of the soldering iron. This tool has » copper bit similar to that used by the tin-plate worker, subject to some variations of form for particular purposes.
In the manufacture of silver plate there are many operations of soldering which, on account of the situation or delicacy of the parts, or some other cause, can neither be performed by the iron, nor yet over the fire. In these cases recourse must be had to the use of the blowpipe, and the flame of a large lamp with a great wick, or of a jet of gas. The latter is now commonly used where it can be had, and is found to be the cleanest, readiest, and most economical for the purpose. The subjoined cut will give some idea of the arrangements for soldering by means of gas.
A (Fig. 82.) is the open hearth place under which the operation is performed. B is the tube connected with the gas main, from which it may be shut off by the cock C. The latter tube terminates in a hemispherical head perforated with small holes, like the rose of a common watering can, and through which, as at D, the gas issues. E is the blowpipe, the air-jet of which is produced by the operation of the small bellows F, through a tube laid for the purpose. A treadle upon the floor at the termination of the string G enables the workman to sustain and regulate the blast with his foot, instead of, as formerly, puffing with his breath; a practice at once injurious and. inconvenient in a high degree, and which is now generally laid aside for the bellows, even in manufactories where oil continues to be used. In some very delicate work, the small portable blowpipe is still used in the mouth.
In the manufacture of plated articles of all but the very cheapest kinds, it is common to mount them with edges, and adorn them with ornaments of silver; these, though sometimes exceedingly light and thin, considerably enhance the value, as they ensure the durability of the article as to beauty in a high degree. In 1824, Mr. Roberts, of Sheffield, silver plater, obtained a patent for a new mode of preparing for and putting on these ornamented silver edges. The methods hitherto used with such goods, when the edges were of an indented kind, were to indent by filing the edge of the plated metal on which the ornamented silver edge was to be fitted and soldered, so that it should correspond with the shape of the silver edge; and then, either thinning the metal, or soft soldering a silver thread (to protect it) along the indented edge. The disadvantages of these methods are stated by the patentee to be, first, the raw edge of the copper must be frequently exposed conspicuously to view; if not at first, certainly after a little use; in the second, the thread that is put on must at once attest that the article is a plated and not a silver one. Mr. Roberts's improved method is, after filing the edge of the article to nearly the shape (but somewhat less) of the ornamental indented silver edging, to hard-solder a silver thread of the required strength upon the said edge; and then to flat it with a hammer upon the stake to the breadth and strength required, and so as that the outer edge will extend a little beyond the ornamented edge, which is then to be soft-soldered on in the usual way. The projecting part of the hard.soldered silver edge which extends beyond the stamped silver one is then to be filed off, and the two edges burnished together till the joining disappears. By this method, it is said, that a workman will scarcely be able to distinguish a plated from a silver article, and that the edges themselves will endure almost as long as solid silver, without the copper becoming at all perceptible. It is, indeed, surprising how long plated articles, defended with silver on the more exposed parts, will last, when carefully used, without wearing through to the copper, and particularly so when not roughly handled in the cleaning.
The reflectors which have for many years been employed in the northern and other lighthouses on our coasts are of this material; namely, copper coated with silver, in the proportion of six ounces of silver to one pound avoirdupois of copper. The metal is rolled at Birmingham or Sheffield, and afterwards, with much labour and great nicety, by a process of hammering, formed to the parabolic curve of a mould made with the utmost precision; these are then polished. These mirrors measure each from twenty-one to twenty-five inches in diameter.
One very ingenious department of the plate-working manufacture consists in what is called chasing or embossing; these terms being used respectively as the work is superficial or deep in the execution. To this practice the gold and silver smiths of antiquity are much indebted for the perfection of their wares; it is, indeed, a process which, next to the art of engraving, and with much greater effect, exhibits in wonderful perfection the designs of the draughtsman. It embodies not merely outline with bold relief, but superadds diversity of texture, surface, and even colour; and some pieces wrought of the precious metals, ornamented in the first style of the art, are of extraordinary value, and justly command universal admiration. Those who have seen the superb table services of the British sovereign, or those of some of the other princes of Europe, as well as many in private hands, and especially the plate repositories of the celebrated house of Rundle and Bridge on Ludgate Hill, will be able to judge of the truth of these remarks. The method of performing the work is very simple as to the details. The article being finished from the brazier, the design is in the first place delineated upon it in a very slight way, or, if it be not original, by means of red chalk and tracing paper, as is done by the engravers. The work, if at all hollow, as a teapot or a mug, and if the figures are to project considerably, is held upon a sand-bag, and the body of the design is bulged from the inside by the application of a hammer upon a knobbed rod called a snarling iron; the vessel is then filled with a composition of pitch and ashes from the grate, and rested upon the sand-bag during the operation on the outside where the work is perfected. If it be a salver, or other flat article, it is embedded upon a quantity of the composition laid on a board of the proper size, and having a hemispherical under-piece resting in a cavity on the work-bench, by which contrivance it is readily turned' about by the chaser, so as to suit his convenience. The lines are then sunk by striking down upon and indenting the metal with little blunt steel punches of shapes adapted to the figure. It would surprise a stranger to see with what facility a workman, by means of a small hammer, and about a score of simple tools, will bring up in bold relief the most elaborate designs.
When the articles are finished in all their parts, the edges dressed, the ornaments soldered on, and the chased or embossed work executed, they are boiled in a lixivium of pearl ashes, to take away the rosin or grease which may remain attached; after which, the raised parts are got up by dry brushing with a mixture of rouge and whiting, and finally by burnishing. The burnishing of plate is an operation to which it is indebted for that rich lustrous appearance so peculiar to the precious metals when thus got up. The burnishes comprise those of steel and those of blood-stone, the latte fixed by means of cement in ferrules attached to the hafts: they are of various forms, suited to the purposes for which they may be required. In burnishing (which is generally performed by women), the first process is to touch the article over with a little brown soap and water, to counteract any greasiness, and then they apply a rough stone burnish, called rough only as being less exquisitely polished than the others; it obliterates any scratches which may exist, and, as it were, lays the ground: this is followed by a steel tool, then comes the middle stone, and lastly the fine stone is used. These tools are occasionally dipped, during the using, in water in which a little white soap has been dissolved. The articles are finally wiped up with pieces of soft chamois leather. Silver vessels are often gilt inside, and even the copper of plated ones is generally so covered. This operation is performed by laying on a coating of the amalgam prepared as for button gilding, and then dissipating the mercury by exposure to a moderate heat, after which the surface is burnished as above described. The gilding, however, is generally applied at an early stage of the manufacture of the goods, mostly after all the hard soldering has been done; the feet, handles, and ornaments being attached afterwards by brasing the iron: for while the gold would suffer by exposure to a heat sufficiently intense to fuse hard solder, the gilding, on the other hand, requires a temperature more than sufficient to melt off any parts united by a mixture of lead and tin.
In some silver articles there are parts, particularly representations of the human figure, and also animals, which are exhibited in matted or dead work, of a fine white ground, and producing a pleasing effect in contrast with the burnished portions. This effect is produced by covering the subject with a coat of pulverised charcoal and saltpetre, and often heating it until red hot over a charcoal fire, quenching it in a pickle of sal enixon. Sometimes the first operation will be sufficient: but if not, the operation must be repeated, until the fine white ground is produced. In some of the very rich and massy pieces of plate, the figures, instead of being stamped and embossed in sheet metal, are cast from designs modelled expressly by celebrated artists in wax, and copied in plaster of Paris. The London gold and silver smiths sometimes employ first-rate talent in this way.
In the seventeenth century the taste for massive silver tankards and cups was at its height, and this taste extended even to the taverns; so much so, indeed, that in 1696, the use of silver plate (spoons excepted) was prohibited in public houses, in which it was then much used both in town and country; insomuch that we are told one alehouse, near the Royal Exchange, in London had to the value of £500 in silver tankards, &c.
The making of silver ladles, spoons, forks, sugar nippers, &c. is generally carried on by persons as an entirely independent branch of trade, and mostly in London. This is an important department of the business of the general silversmith; less, however, on account of the beauty of the articles as compared with many others, than from the large amount of metal consumed in their manufacture. The silver table spoons which immediately succeeded those of pewter were very flimsy and light in comparison of those now generally made. 'The introduction of tea," says Mr. Jacob, "but especially the extensive preference which it gradually received, till it has become the daily fare of almost the whole community, had an influence on the consumption of silver for small spoons. They were scarcely known in the previous reign, but multiplied in the reign of Anne, and have gone on increasing from that time to the present, when they may be counted by millions, perhaps by hundreds of millions." The same authority informs us that the silver used in modern forks and spoons forms the mode in which one half of that metal consumed in England is applied. These articles are wrought upon the anvil, in the manner of steel wares, or, in some sorts, pierced out of sheets by means of the fly, and afterwards fashioned by striking in bosses and filing. They are known in the shops according to the style of the handles, as plain, fiddle-shaped, and king's pattern; the embossed work on the latter description being produced by squeezing them when red hot between figured steel dies by means of a Bramah's press. They are got up by brushing and buffing with oil and rottenstone. These articles, which are almost exclusively formed by manual labour, and in which the intrinsic value of the material constitutes so large a portion of the ultimate cost, could only be sold at the usual prices in consequence of the perfection attained in the irt, by men exclusively devoted to this particular branch. The metropolitan makers long enjoyed the prerogative it using a somewhat lower value of silver as standard, which no longer exists.
To be continued.
Trev.