(a) 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 dry 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 forgo 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 one, 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} in. 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 a 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 are soldered together, using rosin.
(6) 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.
(c) 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 fee obtained; then well wash with water, dry, and brush. One part of perchloride of iron and two parts of water mixed together, and the article 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 article 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.