GOLD-WORKING. We are in the habit of associating our ideas of mines of gold with a few favoured spots ; but in truth this precious metal is very widely diffused through out the world. Spain has gold among the sands of the Tagus, but in too small quan tity to be worth collecting. France, Piedmont, and Tuscany, also present a few traces. In the territory of Salzburg gold occurs in suffi cient quantity to attract attention. Ireland has a little gold among the Wicklow moun tains. But it is in Hungary and Transyl vania that the greatest European deposit is met with ; at Konigsberg, Berson, Schemnitz, Felsobanya, Telkebanya, Kapink, Vorospatak, Offenbanya, Zalatua, and Nagy-ag, in those countries, gold mines are worked, and gold obtained to the extent of one to two thousand lbs. annually. Asia presents numerous gold mines at Breezof and other places on the Ural, and especially in Siberia ; in Tibet, Lydia, Japan, and Ceylon. The Eastern Archipelago presents traces of gold in For mosa, Java, Sumatra, Borneo, and the Philip pines. Africa presents its store of gold dust, in greater or less quantity, in Kordofan, Sofala, and the wide region which bounds the Sahara desert on the south. America is, however, the richest part of the globe for gold. In Brazil, Chili, Peru, Ecuador, New Grenada, Mexico, North Carolina, and—last, though not least— California, this precious metal is found. Per haps we may name California, Siberia, and Brazil, as at present the three richest gold producing countries. From all the countries and districts named, the gold brought to market is mostly derived from alluvial sand, and is extracted by washing.
Under CarivormA and Russr, will be found a little notice of the quantities of gold procured from those countries; but we may here say in addition, in respect to California, that it has lately been ascertained that during the year 1850, gold was shipped as freight from St. Francisco, to the value of nearly 30 million dollars; besides an estimated amount, for gold brought away by returning adven turers, and gold retained in California as a circulating medium, of 18 millions more making 48 million dollars' worth as the pro duce of one year.
The' gold obtained from the sand of river valleys is separated from the sandy particles by repeated processes of washing ; but the smaller grains of gold, which cannot easily be so separated, are subjected to the process of amalgamation by means of quicksilver. Sometimes the gold is found mixed with sal phurets of copper, silver, arsenic, or other metals ; and to separate these sulphurets re quires the combined processes of washing and amalgamation. The recent furor concerning California has led to the invention of a num ber of new machines to facilitate the separa tion of the gold from the sands. A gold win nowing machine, recently introduced at Paris, is intended for emigrants to California. Leaving out the separate lumps of gold, it is said that the auriferous sands yield about one ounce of gold in 500 lbs. of sand ; so that this weight of sand must be washed, before the gold can be procured. The new winnowing machine is intended by its inventors to sepa rate much more gold from the sand than by the ordinary washing, and to do it much more quickly. The machine acts by keeping up a
constant agitation among the particles, with a provision to allow the escape of the earthy matter. The sand is put into a kind of hopper, whence it descends into a receptacle where a rotating fan or winnow works ; the winch which works this fan at the same time pumps up water from a river through a hole ; the sand and water flow down a trough into the river, while the gold is left in the machine. It is said that one of these machines is to be sent to the Great Exhibition.
The working of gold into purposes of use and ornament gives rise to many important and interesting branches of manufacture. The coining of gold into money is noticed under MINT; and the making of thin leaves under Goan BEATING. Gold and silver plate is an important branch of manufacture. By mechanical means (pressure between steel rollers) a thin layer of gold or silver may be made to adhere to a thicker plate of some cheaper metal ; hut true gold plate has no such inferior layer. The processes of rolling, casting, punching, chasing, hammering, stamping, soldering, riveting, all conic into requisition in the manufacture of a piece of gold plate. The approaching Exhibition will contain many magnificent specimens of this art, especially from London and Paris ; some of the works from Paris will be of great value. The Goldsmith's Company of London, in order to encourage an art with which they axe so intimately connected, have offered rewards to the amount of 10001. for the best specimens prepared for the Exhibition. The prizes are to be one of 2001., three of 1001., three of 501., three of 301., six of 251., three of 201., two of 151. and two of 101. The articles are to be the modelling and manufacture of British artists; they are to bear the London Hall mark of 1850-1 ; and they may be of silver, silver-gilt, or gilt in part. The articles named are groups of figures, table candelabra, shields, salvers, sideboard and altar dishes, dessert services, sideboard ewers, ornamental cups, entree dishes, candlesticks and light-branches, tea and coffee services, communion services, salt cellars, claret jugs, bread or cake baskets, tea or coffee salvers, tea kettles, inkstands, spoons, and forks.
A considerable quantity of gold is used in the manufacture of watch-cases; but much more is consumed in the numerous trifles which come under the general name of jewellery. Pencil cases, pen-holders, thimbles, bodkins, toothpicks, tweezers, broaches, finger-rings, watch-rings, ear-rings, chains, bracelets, buckles, clasps, (bc.—these lead to a large consumption of gold in London and Birming ham, and to the employment of a considerable number of persons. Some of these small trinkets are made of solid gold, some with a thin film of gold on a substratum of silver or copper. Most of these articles are made by persons who receive the material from manu facturers or wholesale dealers, and who em ploy a few apprentices and assistants to make up the trinkets. Lathes, vices, rollers, ham mers, punches, files, draw-plates, wire-drawing apparatus—all these, on generally a small scale, are employed in working up the gold to the required form.