(THE USES OF). Metallic copper is used for culinary vessels in many parts of Europe, and, for this purpose, the inner surface of the vessel should be tinned. Large vessels for brewing, dyeing, and the like processes, are made of copper. The making of these vessels constitutes the ordinary business of the coppersmith.

Copper, rolled into sheets, is employed for covering the wooden work of the roofs of churches and large edifices in Germany, Sweden, and other countries. It is a costly covering, and does not possess any notable advantage over lead.

A modern, and now a very extensive, use of sheet-copper is, for the sheathing of ships. That part of the hull of the ship that is in the water is covered with sheet-copper; this covering preserves the wood from the attacks of the worm, and also gives the ship the property of passing more rapidly through the water, as the copper bottom remains always smooth, and does not become foul; for sea-weed and shells will not take root and attach themselves to copper as they do to the bare planks.

Copper bolts are used for fastening the planks and timbers of ships. This is a modern improvement in ship-building. A copper fastened ship or boat is preferable to one with iron fastenings, because the copper bolts remain unaltered by rust, and outlast the wood which they hold together.

Copper plates are used for etching and engraving. Laminated copper is cut into rectangular pieces of the sizes required for different engravings, and the pieces are hammered, scraped smooth, and polished by coppersmiths, who make the preparation of these plates their principal business. The copperplate engraver cuts his design or drawing in furrows on the plate; fills these furrows with ink, and paper being pressed against the plate, the ink is transferred to the paper, and a copy of the drawing is thus got on paper. Copper is the most convenient metal for this sort of engraving; silver has the requisite physical qualities, but it is too scarce and costly; pewter, being soft, is more easily worn by impression than copper; it serves, however, in less delicate work, and is generally used for engraving music.

For the frames of delicate dipping needles and magnetic compasses copper is employed, as it was found that the brass, generally used in philosophical instruments, sometimes contained iron which might affect the magnetic needle.

Copper is drawn into wire, used for the communication with the bells in houses, and for other purposes.

Small pipes for conveying the pit-coal gas from the level of the street to the aperture by which the gas issues, are made of copper or of brass. These pipes are fitted on an iron cylindrical mandril; and a cylindrical ring is drawn over the outside; in this way copper and brass tubes are drawn out. The brass tubes for telescopes are drawn out in the same manner.

Copper coins have been used as a medium of exchange, for objects of small value, by most nations, ancient as well as modern. Greek and Roman copper coins abound in the cabinets of collectors.

The mixture, consisting of a large proportion of copper and a small proportion of silver, called billon in France, is used for coins of small value in that country, Germany, and other parts of Europe. In Britain this alloy is not now used, and the coins are made either of standard gold, of standard silver, or of copper. The use of billon is blameable, as it renders the value of the coins uncertain.

Copper may be plated, that is, its surface may be covered with a layer of silver, by rubbing the surface with a mixture of nitrate of silver, muriate of soda, and acidulous tartrate of potass (cream of tartar). But the method practised at Birmingham is the most permanent and effectual; a plate of copper, with a plate of silver applied to it, and borax placed in the interstice, is heated to a particular degree, which requires the skill of the workman to know; it is a degree of heat near that at which copper and silver melt. The two metals thus heated, and in contact, are taken out of the furnace and passed through rollers. There is a fusion and combination of the adjacent surfaces, and their adhesion is perfected by the pressure of the rollers. Copper thus plated is manufactured at Birmingham into candlesticks, teapots, buttons, buckles, and a variety of other articles.

Standard silver coins contain a small proportion of copper, which is useful to give them hardness; this proportion is regulated by each government in Europe; the proportion varies a little in different countries. The combination of gold and copper in various proportions is used for making rings and other trinkets.

Copper is gilded by applying on its surface an amalgam of gold with mercury. Bronze ornaments are gilded in the same way.

Copper united with tin forms bronze. This combination is hard and brittle if the proportion of tin is great; but when the proportion of tin is small the bronze is soft, and possesses tenacity so as not to be easily broken. Ancient nations employed hard bronze, containing much tin, in making sword blades, spear heads, hatchets, and cutting instruments. Bronze cramps are found in ancient buildings in Egypt. Statues and bas-reliefs, various culinary vessels, and different kinds of instruments of soft bronze, are seen in the collections of antiquities. In modern times soft bronze is used for casting cannon and statues.

Copper melted with a large proportion of tin constitutes bell-metal, which is hard and brittle. The metal of which the Chinese gongs are made is composed of the same ingredients; it has the property of being malleable in some degree at a certain stage of its cooling, for the gongs are covered with marks of the hammer.

Copper exposed hot to the metallic vapour of zinc constitutes brass. The good quality of the brass depends much on the malleability and goodness of the copper employed in making it. There occur no ancient Greek or Roman instruments of this mixture; it is to be inferred, therefore, that they were not acquainted with it. It was employed in Europe after the fall of the Roman empire, as appears from the brass plates on tombs of the middle ages. The Chinese work in brass; and the only coins they have are pieces of small value composed of brass containing much zinc. In Europe brass is used for culinary vessels; the ornaments of household furniture; the ornaments of horse-harness and of coaches; mathematical and philosophical instruments, for which also silver has the requisite physical qualities, but is too dear; the barrels of small pumps; the wheels and other parts of the machinery of clocks and watches; in the form of wire for making pins; and for some of the strings of harpsichords and guitars, the strings which give the higher notes being of iron wire. Brass is less tough than copper, it is brittle whilst hot. It is more easily melted and cast, and undergoes the action of the file and the turning lathe better than copper, qualities which render it convenient for the above-mentioned uses.

To obtain copper from the pyrites, otherwise called sulphuret, which is its most frequent ore, it is necessary to smelt the pyrites several times before the metallic copper is obtained free from sulphur; the slag or scoria produced in these smeltings is formed into large bricks, used in building in Wales and some other parts of Britain.

The chief use made of the native combinations of copper found in the earth is to extract the metallic copper from them; sulphur is sometimes manufactured in treating the copper pyrites. Some native oxides and native carbonate of copper are collected in the mines of Hungary, for the purpose of being employed in painting.

Oxide of copper obtained from the annealing that copper and brass wire undergoes, is used in dyeing.

In enamel colouring, oxide of copper, at a low degree of oxidation, produces an opaque red or brownish red enamel, called porporino. When the copper is more oxidated it gives a green colour in enamel colouring, in colouring upon earthenware and porcelain, and in stained glass.

Sulphate of copper, when concentrated or crystalized, is transparent and blue; it is manufactured for the use of the dyer and calico printer.

Nitrate of copper is also blue. It has been proposed to impregnate sticks of soft wood, such as poplar or fir, with a solution of this salt. These sticks, thus impregnated and dried, when they are lighted burn gradually to the end, and may serve as quick match for firing cannon.

Muriate of copper is green; that which is formed by direct solution of copper in muriatic acid is transparent, and soluble in water; but the native muriate of copper, with excess of oxide, is insoluble. This is found in Peru in the form of green sand, and being opaque, may be used in painting.

Verdigrise (verdit-gris) is an acetate of copper with excess of oxide. It is prepared in the wine districts of the south of France, by laying copper plates in strata alternately with the grape stalks and husks from which the juice has been pressed. The fermentation of the husks produces vinegar, which acts upon the copper. Verdigrise is used in painting, because it possesses, on account of its excess of oxide, the opacity necessary for making a coloured paste with oil; it is also used in dyeing. Crystallized acetate of copper is the acetate without excess of oxide; it is in green crystals, and is used in dyeing.

Scheele's green is an opaque precipitate, of a grass-green colour, composed of copper and arsenic. It is used in oil painting.

Prussiate of copper is an opaque brown precipitate, formed by adding prussiate of potash to a solution of sulphate of copper, and may be used in painting. The colour, however, wants durability.

An Account of all Copper Imported into Great Britain in the year ending 5th January 1817.

| Description | Quantity | |--------------------------------------|----------| | Unwrought in Bricks, Pigs, &c. | | | Copper in Plates and Coins | | | Old Copper for re-manufacture | | | Copper Ore | | | Total quantity Imported | |

Exported:

| Description | Quantity | |--------------------------------------|----------| | Unwrought in Bricks, Pigs, &c. | | | Copper Coin | | | Sheets, Nails, &c. | | | Wire | | | Wrought Copper of all other sorts | | | Total of British Copper Exported | | | Foreign Copper unwrought, &c. Exported| |