BOOK IX.

379

of the bellows, and blows up the fire with the bellows ; thus within the spaceof half an hour the forehearth, as well as the hearth, becomes warmed, andof course more quickly if on the preceding day ores have been smelted in thesame furnace, but if not then it warms more slowly. If the hearth andforehearth are not warmed before the ore to be smelted is thrown in, the furnaceis injured and the metals lost; or if the powder from which both are madeis damp in summer or frozen in winter, they will be cracked, and, givingout a sound like thunder, they will blow out the metals and other substanceswith great peril to the workmen. After the furnace has been warmed, themaster throws in slags, and these, when melted, flow out through the tap-hole into the forehearth. Then he closes up the tap-hole at once withmixed lute and charcoal dust; this plug he fastens with his hand to around wooden rammer that is five digits thick, two palms high, with a handlethree feet long. The smelter extracts the slags from the forehearth with ahooked bar ; if the ore to be smelted is rich in gold or silver he puts into theforehearth a centumpondium of lead, or half as much if the ore is poor,because the former requires much lead, the latter little ; he immediatelythrows burning firebrands on to the lead so that it melts. Afterward heperforms everything according to the usual manner and order, whereby hefirst throws into the furnace as many cakes melted from pyrites 12 , as herequires to smelt the ore ; then he puts in two wicker baskets full of orewith litharge and hearth-lead 13 , and stones which fuse easily by fire of thesecond order, all mixed together ; then one wicker basket full of charcoal,and lastly the slags. The furnace now being filled with all the things Ihave mentioned, the ore is slowly smelted ; he does not put too much of itagainst the back wall of the furnace, lest sows should form around the nozzlesof the bellows and the blast be impeded and the fire bum less fiercely.

This, indeed, is the custom of many most excellent smelters, who knowhow to govern the four elements 14 . They combine in right proportion theores, which are part earth, placing no more than is suitable in the furnaces ;they pour in the needful quantity of water; they moderate with skill the airfrom the bellows ; they throw the ore into that part of the fire which bumsfiercely. The master sprinkles water into each part of the furnace to dampenthe charcoal slightly, so that the minute parts of ore may adhere to it,which otherwise the blast of the bellows and the force of the fire would agitateand blow away with the fumes. But as the nature of the ores to be smeltedvaries, the smelters have to arrange the hearth now high, now low, and toplace the pipe in which the nozzles of the bellows are inserted sometimes on agreat and sometimes at a slight angle, so that the blast of the bellows may

lz Panes ex fiyrite conflati. While the term matte would cover most cases where thisexpression appears, and in many cases would be more expressive to the modern reader, yetthere are instances where the expression as it stands indicates its particular origin, and ithas been, therefore, considered advisable to adhere to the literal rendering.

ls Molybdaena. See note ?7, p. 476. It was the saturated furnace bottoms fromcupellation.

14 The four elements were earth, air, fire, and water.