with oil, and melted together. Used in the commoner kinds of tea-boards, &c. Silver Bronze.-Bismuth and tin, of each 2 lbs.; melt together and add 1 lb. of quicksilver. Pound all together into a powder. This soft fusible amalgam is used as an imitation of silver bronze for plaster figures and other common purposes, in the same way as the aurum musivum is for gold-coloured articles. It may be used as spangles in sealing-wax; it must then be mixed when the resinous part of the wax is getting cold. Gold Powder for Bronzing.Leaf gold is ground with virgin honey on a stone, until the leaves are broken up and minutely divided. The mixture is removed from the stone by a spatula, and stirred up in a basin of water, whereby the honey is melted and the gold set free; the basin is then left undisturbed until the gold subsides; the water is poured off, and fresh quantities added until the honey is entirely washed away; after which the gold is collected on filtering paper, and dried for use. Gold Size is prepared from lb. of linseed oil with 2 oz. of gum animi; the latter is reduced to powder and gradually added to the oil while being heated in a flask, stirring it after every addition until the whole is dissolved; the mixture is boiled until a small quantity, when taken out, is somewhat thicker than tar, and the whole is strained through a coarse cloth. When used, it must be ground with as much vermilion as will render it opaque, and at the same time be diluted with oil of turpentine, so as to make it work freely with the pencil. | go over the figure with it, allowing no more to remain than causes it to shine. Set it aside in a dry place free from smoke, and in forty-eight hours the figure is prepared to receive the bronze. After having touched over the whole figure with the bronze powder, let it stand another day, and then with a soft dry brush rub off all the loose powder, particularly from the points, or more prominent parts of the figure. Bronzing Wood.-The wood is first covered with a uniform coating of glue, or of drying oil, and when nearly dry the bronze powder, contained in a small bag, is dusted over it. The surface of the objects is afterwards rubbed with a piece of moist rag. Or the bronze powder may be previously mixed with the drying oil, and applied with a brush. Bronzing Paper.-Gum is substituted for drying oil in bronzing paper When dry, the paper is submitted to the action of the burnisher, which imparts great brilliancy to it. Bronzing small Brass Articles.-1 part oxide of iron, 1 part white arsenic, 12 parts hydrochloric acid. Clean the brass well to get rid of lacquer or grease, and apply with a brush until the desired colour is obtained. Stop the process by oiling well, when it may be varnished or clear lacquered. Bronzing Gas Fittings.-Boil the work in strong ley, and scour it free from all grease or old lacquer; pickle it in diluted nitric acid till it is quite clean (not bright), then dip in strong acid, and rinse through four or five waters; repeat the dip, if necessary, till it is bright; next bind it very loose Bronzing Plaster. Lay the with some thin iron wire, and lay it in figure over with isinglass size, until it the strongest of the waters you have holds out, or without any part of its used for rinsing. This will deposit a surface becoming dry; then, with coat of copper all over it if the water brush, such as is termed by painters a or pickle be not too strong; if such is sash tool, go over the whole, taking care the case the copper will only be depoto remove, while it is yet soft, any of sited just round where the wire touches. the size that may lodge on the delicate When the copper is of sufficient thickparts of the figure. When it is dryness wash it again through the waters, take a little very thin oil gold size, and and dry it with a brush in some hot with as much as just damps the brush, saw-dust; box-dust is best, but if this is a not at hand, oak, ash, or beech will do, I add turpentine, about twice its own It is now ready for bronzing. The volume, to the whole, mix with a bronze is a mixture of black-lead and camel-hair brush, and apply to the red bronze, varied according to shade brass work. required, mixed with boiling water. The work is to be painted over with this and dried, then brushed until it polishes. If there are any black spots or rings on the work, another coat of the bronze will remove them. Lacquer the work with pale lacquer, or but very slightly coloured, for if it is too deep it will soon chip off. Another method is to mix vinegar or dilute sulphuric acid (1 acid 12 water) with powdered black-lead in a saucer or open vessel; apply this to the brass with a soft plate brush by gentle brushing. | This will soon assume a polish, and is fit for lacquering. The brass must be made slightly warmer than for lacquering only. A little practice will enable the operator to bronze and lacquer with once heating. The colour, black or green, varies with the thickness of black-lead. Green Bronze.-Dissolve 2 oz. of nitrate of iron, and 2 oz. of hyposulphite of soda in 1 pint of water. Immerse the articles in the bronze till of the required tint, as almost any shade from brown to red can be obtained; then well wash with water, dry, and brush. One part of perchloride of iron and two parts of water mixed together, and the brass immersed in the liquid, gives a pale or deep olive green, according to the time of immersion. If nitric acid is saturated with copper, and the brass dipped in the liquid, and then heated, it assumes a dark green. If well brushed, it may be lacquered with pale gold lacquer, or else polished with oil. Black Brasswork for Instruments. Take lampblack, about a thimbleful, and put it on a flat stone or smooth slate; add four or five spots of gold size, and well mix with a palette knife, make the whole about as thick as putty; well mix. The less gold size there is the better, so that the lampblack just sticks together; if too much gold size be added, the effect will be a bright black and not a dead black. Now Black Bronze for Brass.-Dip the article bright in aquaforts; rinse the acid off with clean water, and place it in the following mixture until it turns black-Hydrochloric acid, 12 lbs.; sulphate of iron, 1 lb.; and pure white arsenic, 1 lb. It is then taken out, rinsed in clean water, dried in saw-dust, polished with black-lead, and then lacquered with green lacquer. Bronzing Iron.-To one pint of methylated finish add 4 oz. of gum shellac and oz. gum benzoin; put the bottle in a warm place, shaking it occasionally. When the gum is dissolved let it stand in a cool place two or three days to settle, then gently pour off the clear into another bottle, cork it well, and keep it for finest work. The sediment left in the first bottle, by adding a sufficient quantity of spirit to make it workable, will do for the first coat or coarser work when strained through a fine cloth. Next get lb. of finely-ground bronze green, the shade may be varied by using a little lampblack, red ochre, or yellow ochre; let the iron be clean and smooth, then take as much varnish as may be required, and add to the green colour in sufficient quantity; slightly warm the article to be bronzed, and with a soft brush lay a thin coat on it. Wheu that is dry, if necessary lay another coa on, and repeat until well covered. Take a small quantity of the varnish and touch the prominent parts with it; before it is dry, with a dry pencil lay on a small quantity of gold powder. Varnish over all. Bronzing Copper Utensils.— If the article is not new take it to pieces, wiping off all the solder with a wisp of tow, and taking care not to let any of the metal in the fire; then twist a little tow on the end of a stick, and pickle with spirits of salts all those parts that are tinned, pickling the outside as well as the in, rinse in water, and scour outside with wisp of tow and sand, fine coke-dust is best for the tinned parts, which must be brought quite clean, rinse clean, smear the outside with wet whiting, and then tin with bar tin, sal ammoniac being the best agent; then pickle only the outside with diluted spirits of salts, rinse, and scour with clean sand till the surface is perfectly clean and bright, taking care to rub as much as possible in one direction. The cast parts and those not tinned are pickled in dilute oil of vitriol, | and scoured with sand, same as the body; beat with a brush, then dried in saw-dust, and the article is now ready for bronzing. Procure some crocus, some knowledge is wanted to select a good one, as it may be too light, or too dark, or too fine, or too coarse; then make into a thick cream with water. Having used a forge fire to tin with, to be on the safe side it is best to rake out all the old coke and light afresh, and the coke should be a nice, clear, firm, grey ore, in pieces the size of a walnut; also have some clear bright coal, then blow up a clear bright fire, and heap up plenty of coke that the sulphur may burn off; now take a little of the mixed crocus and brush up the body, using a hard brush; get all the crocus off clean, and wipe with a clean piece of rag, and it is best to hold with this, as the perspiration of the hand will prevent the colour taking; now blow up fire, making a hole in centre, so that a good blast comes up, and having painted the body evenly with the red cream so that the colour does not run (a flat camel-hair brush, 2 inches wide, is the best thing to do it with), hold it with the tongs and turn it steadily so that all parts are exposed fairly to the blast. As soon as it is dry, throw into the fire a bit of coal about the size of a Spanish nut, more or less to size of work, and let the work have an even coat of smoke till it is quite black, but no more (if the coal is not burnt out hold the work on one side), then turning it steadily, keep up a sharp blast till the smoke is burnt off, and stand it to cool. Treat cast parts the same, but as soon as the smoke is burnt off, dip them into clean cold water, else, on account of their thickness the colour will burn; when cold, wipe the crocus off the body with wisp of clean tow, then brush hard till quite clean, wipe with rag and repeat the above once or twice, according to the shade required. To finish properly the body is hammered all over with bright hammers shaped to parts, and on suitable tools which are covered with two or three folds of lasting; the inside is scoured bright, and the parts soldered together, using resin. Medals only want brushing up with wet crocus, taking care not to touch with hand, and then colouring as above. Only copper coins can be so bronzed. Copper Articles may also be bronzed by the following process :-Dissolve in vinegar two parts verdigris and one part sal ammoniac. Boil, skim, and dilute with water, until white precipitate ceases to fall. Set in a pan meanwhile the articles to be bronzed, made perfectly clean and free from grease. Boil solution briskly and pour over the articles in the pan and boil them briskly. A bright reddish-brown colour is thus acquired; but the articles should be frequently inspected, and removed as quickly as the desired shade is obtained. Then they are to be repeatedly washed and dried. The solution must not be too strong, for then the bronze will come off by friction, or turn green on exposure to the air. То Bronze Electrotypes, Green. - Steep the medal or figure in a strong solution of common salt or sugar, or sal ammoniac, for a few days, wash in water and allow to dry slowly, or suspend over a vessel containing a small quantity of bleaching powder, and cover over the length of time it is allowed to remain will determine the depth of the colour. Brown.-Four or five drops of nitric acid to a wine-glassful of water, and allowed to dry, and when dry impart to the object a gradual and equal heat; the surface will be darkened in proportion to the heat applied. Black.-Wash the surface of the object over with a little sulphurate of ammonia (dilute), and dry at a gentle heat, polish with a hard brush afterwards. Browning Gun Barrels.-Chloride of antimony has been much used for bronzing gun barrels, is excellent in its operation, and has been called, in consequence, bronzing salt. It is used for bronzing, mixed to a thin creamy consistence with olive oil; the iron is slightly heated, dressed evenly upon its surface with this mixture, and left until the requisite degree of browning is produced. The sharpening of the chloride of antimony can be effected by adding a little nitric acid to the paste of olive oil and chloride of antimony, so as to hasten the operation. Another formula is-Aquafortis,oz.; sweet spirit of nitre, oz.; spirit of wine, 1 oz.; blue vitriol, 2 oz. ; tincture of chloride of iron, 1 oz.; water, 40 oz. Dissolve the blue vitriol in the water, then add the other materials, and the water is warmed to dissolve the blue vitriol; let it get cold before adding the other materials. The burnishing and marking can be effected with the burnisher and scratch brush. The polishing is best effected by rubbing with a piece of smooth, hard wood, called polishing wood. It is lastly varnished with shellac varnish, and again polished with the hard wood polisher. Some prefer the tone of brown produced by blue vitriol, 1 oz.; sweet spirit of nitre, 1 oz.; water, 20 oz. In any case, the surface of the iron must be well cleaned, and rendered quite bright; it is then freed from grease by rubbing with whiting and water, or better, with powdered quicklime and water. browning composition is then placed on, and allowed to remain twenty-four hours. It is then rubbed off with a stiff brush. If not sufficiently browned, repeat the last process after browning. Clean the surface well with hot water containing a little soda or potash, and, lastly, with boiling water, and dry it. The surface can be burnished and polished. Varnish with tinsmith's lacquer, or with gum shellac, 2 oz.; dragon's blood, 3 drs.; methylated spirits of wine, 4 pints. The metal should be made hot before applying this varnish, and will The | present an excellent appearance. If the varnish is not required to colour, but only to preserve the actual tint pro duced on the metal surface by the browning fluid, leave out the dragon's blood. Catgut, To Make. - Take the entrails of sheep, or any other animal, procured from the newly-killed carcass. Thoroughly clean them from all impurities and from attached fat, and wash them well in clean water; soak in soft water for two days, or in winter three days, then lay them on a table and scrape them with a small plate of copper, having a semicircular hole cut in it, the edges of which must be quite smooth and not capable of cutting. Now, after washing, put them into fresh water, and there let them remain till the next day, when they are again to be scraped. Let them soak again in water for a night, and two or three hours before they are taken out add to each gallon of water 2 oz. of pearlash. They ought now to scrape quite clean from their inner mucous coat, and will consequently be much smaller in dimensions than at first. They may now be wiped dry, slightly twisted, and passed through a hole in a piece of brass, to equalize their size; as they dry, they are passed every two or three hours through other holes, each smaller than the last. When dry they will be round and well polished, and being oiled are fit for use. Cameos, To Carve.-Take the common helmet, or the red helmet shell (those shells whose inner surface is pink or dark coloured are most suitable), cut them into squares with a lapidary's mill, round off the corners, and shape them into an oval on a wet grindstone. Fix the enamel side on a short stick with jeweller's cement, grind off the brittle surface, sketch the subject with a black-lead pencil, cut the subject with engraver's tools, namely, a chisel tool to clear the bare places; a lozenge-shape for forming the subject, and a scraper, made of a three-angled file, ground off taper to the point, for cleaning the enamel surface round the subject, and also for forming the lineaments and other delicate parts The colour on the cheeks and hair is produced by leaving the layer of coloured shell on those places. The stick must be grasped in the left hand, and held firmly against a steady bench, and with the tool resting in the hollow of the right hand, dig away the shell. A convenient length for the tools is three inches and a half; they must be kept in good condition to work with accuracy. The cameos are polished with a cedar stick, or a piece of cork dipped in oil of vitriol and putty powder, and cleaned with soap and water. Mother-of-pearl is carved in the same way. and bottle and cork it until wanted for use, then mix it with boiled oil and dryers until as thick as putty. Mix the cement only in small quantities, as it dries quickly. 2. Mix boiled linseed oil, litharge, red and white lead together, using white-lead in the largest proportion, spread on flannel, and place on the joints. 3. A solution of glue, 8 oz. to 1 oz. of Venice turpentine; boil together, agitating all the time, until the mixture becomes as complete as possible, the joints to be cemented to be kept together for forty-eight hours if required. 4. Take a gill of gold size, 2 gills of red-lead, 1 gill of litharge, and sufficient silversand to make it into a thick paste for use. This mixture sets in about two days. Armenian, or Jeweller's Cement.-Dissolve 5 or 6 bits of gum mastic the size of a large pea, in as much spirits of wine as will suffice to render it liquid; in a separate vessel dissolve as much isinglass (previously softened in water, though none of the water must be used) in rum, or other spirit, as will make a 2-oz. phial of very strong glue, adding two small pieces of gum ammo Cements, How to Use.-Take as small a quantity of the cement as possible, and bring the cement itself into intimate contact with the surfaces to be united. If glue is employed, the surface should be made so warm that the melted glue is not chilled before it has time to effect a thorough adhesion. Cements that are used in a fused state, as resin or shellac, will not adhere unless the parts to be joined are heated to the fusing point of the cement. Sealing-wax, or ordinary electrical cement, is a good agent for uniting metal to glass or stone, provided the masses to be united areniacum, which must be rubbed or ground made so hot as to fuse the cement, but if the cement is applied to them while they are cold it will not stick at all. This fact is well known to the itinerant vendors of cement for uniting earthenware. By heating two pieces of china or earthenware so that they will fuse shellac, they are able to smear them with a little of this gum, and join the pieces so that they will rather break at any other part than along the line of union. But although people constantly see the operation performed, and buy liberally of the cement, it will be found in nine cases out of ten that the cement proves worthless in the hands of the purchasers, simply because they do not know how to use it. They are afraid to heat a delicate glass or porcelain vessel to a sufficient degree, or they are apt to use too much of the material, and the result is a failure. Cement for Aquariums. 1. Take 1 gill of plaster of Paris, 1 gill of litharge, 1 gill of fine white sand, of a gill of finely-powdered resin. Mix well, till they are dissolved; then mix the whole with a sufficient heat. Keep it in a phial closely stopped, and when it is to be used, set the phial in boiling water. The preceding is also effectual in uniting almost all substances, even glass, to polished steel. Acid Proof Cement.-Make a concentrated solution of silicate of soda, and form a paste with powdered glass. This simple mixture will sometimes be found invaluable in the operations of the laboratory where a luting is required to resist the action of acid fumes. Cutler's Cement. - 1. Resin, 4 parts, to 1 part beeswax and 1 part of brick-dust, or plaster of Paris. 2. Sixteen parts resin, 16 hot whiting, and 1 wax. 3. Pitch, 4 parts; resin, 4; tallow, 2; and brick-dust, 2. The opening for the blade is filled with one of these compositions. The lower end of the iron heated and pressed in. Cement for Bottle-Corks. The bituminous or black cement for |