These data perhaps require some slight explana-tion.
Standard weight is the weight of a coin as pre-scribed by an Act of George III . Thus 20 lbs. ofstandard gold must contain 934 sovereigns and oneten shilling-piece ; and every pound of standardsilver shall be coined into sixty-six shillings.
Least current weight is the least weight at whichthe Bank can be compelled to accept a gold coinwithout making deduction for wear.
llemedg allowance is the latitude, or, in French ,tolerance allowed to the Mint authorities withinwhich the weight and fineness of coins may vary,as it would be impossible to produce the requisitenumber of coins absolutely correct both as regardsweight and fineness.
Manufacture of Coins. —In describing the mannerin which gold or silver, as received from the refiner,is converted into finished coin, we cannot do betterthan trace its progress from the time of the impor-tation of the bullion in the form of ingots, to its beingpassed into circulation.
Importation. —Although the Mint authorities arelegally compelled by the Coinage Act of 1870 tocoin gold bullion free of charge, at the rate of£3 17*’. 10 \d. per standard ounce, by whomsoeverimported, provided that it is not lower than standardfineness, the right is seldom taken advantage of bythe public, and practically all the gold issued as coinis imported by the Bank of . England. This liberty,however, does not extend to silver, for the money madeof this metal is what is technically termed a “ token ”coinage, that is, it is not intrinsically worth the amountfor which it passes current; an ounce of standard silver,which in the currency is worth 5s. 6d., having anactual market value of about 4s. lOd.; this amount ofcourse is liable to slight variations. Bronze moneyis also a “token” coinage. Thus it will be seen, thata profit of about 14 per cent, is derived from thecoinage of silver money; this profit is called the“seignorage.” It should be noticed, however, thatwhereas in the case of light gold the public arecharged for the amount lost by wear, the Mint isalways obliged to return new silver coin, piece forpiece for worn coin, however muoh it may have lostin weight from this cause.
Gold and silver bullion are received into the Mint as (1) worn coin, (2) foreign coin, and (3) ingots."These latter are in the form of bricks slightly taperingdownwards, and, in the case of gold, generally weighabout 200 ozs., and contain about 98 per cent, offine metal. The silver ingots, which are pur-chased for the mint by a broker, usually weighfrom 1000 to 2000 ozs., and are similar in finenessto those of gold. After being severally weighed,samples are cut off each ingot, and are then sentto be assayed (an operation which will be de-scribed subsequently) by the assayer of the Mint ,who compares his results with those obtained by theimporter’s assayer. In case the two assays do notagree, a “ retrial ” is made, and should this confirmthe first Mint assay, the importer is at liberty to sellon this result, or remove the metal from the Mint .
The importer’s assayer gives both a trade report andits decimal equivalent.
Melting. —The ingots then pass into the meltinghouse, which is divided into two departments,devoted respectively to gold and silver. From theknown weight of the metal and its compositionit is easy to ascertain the amount of alloyingmetal (copper) which must be added in order toreduce it to the required standard of 916 - 6 and925'0, in the cases of gold and silver respec-tively. Plumbago pots are used in both cases,those employed for gold being capable of holdingabout 1250 ozs., and those for silver from 2000 to5000 ozs. of the standard alloy. The metal can, inthe former case, be easily poured by hand, the potbeing merely supported, while held in a pair of tongs,by a rope passing over a single pulley in the roof.With silver, however, in consequence of the largerweight operated upon, mechanical appliances have tobe introduced. The pot, after being raised from thefurnace by means of a common jib crane, is placedin an iron holder, which by means of wheel gearingcan be gradually tilted, thus causing the metal toflow out. The moulds, about twenty-four in number,are fixed in a heavy iron frame, which runs on railsin such a manner as to bring them consecutively underthe lip of the pot. In order to effect this the frameis provided with a longitudinal rack, which gearsinto a spur wheel on the fixed frame supporting themechanism by means of which motion is given tothe pot. Three men are required to work thisapparatus. One turns a handle by which the tiltingof the pot is effected; a second turns another handlein order to bring the moulds consecutively under thelip, at the same time holding back the charcoal (whichalways covers the surface of the metal, in order toprevent oxidation of the copper, whereby the alloywould be rendered too rich) to prevent fragmentsfrom passing into the moulds; while a third workstwo small racks, by which a slight motion maybe given to the moulds to or from the pot, thusinsuring a direct flow of the metal into the mould.In practice, however, it is found impossible to avoidspilling a considerable amount of metal when thisapparatus is employed, the amount spilt in pouringgold, which is done by hand, being almost inappre-ciable. The bars, immediately on being cast, areremoved from the moulds and cooled rapidly. Thefurnace in which the silver is melted is cylindrical inform, being about 30 inches deep and not quite 2feet in diameter, 6 of these being connected with onecentral flue. They are provided with movable fire-bars and lids which slide over the top. Thoseemployed for gold are similar in construction, butsomewhat smaller. It is important to observe that,before pouring, the metal should always be stirredwith an iron, fire-clay, or plumbago stirrer, as thegold (or silver) is liable to settle to the bottom of thepot, owing to its high specific gravity. During thisoperation, moreover, the fireman ascertains, from theviscosity of the molten metal, when it has attainedthe temperature which causes it, when moulded, toform the most workable bars. The bars are all of a