If the copper is not good, the master draws off the "slags" twice, or three times if necessary—the first time when some of the cakes have been melted, the second when all have melted, the third time when the copper has been heated for some time. If the copper was of good quality, the "slags" are not drawn off before the operation is finished, but at the time they are to be drawn off, he depresses the bar over both bellows, and places over both a stick, a cubit long and a palm wide, half cut away at the upper part, so that it may pass under the iron pin fixed at the back in the perforated wood. This he does likewise when the copper has been completely melted. Then the assistant removes the iron plate with the tongs; these tongs are four feet three palms long, their jaws are about a foot in length, and their straight part measures two palms and three digits, and the curved a palm and a digit. The same assistant, with the iron shovel, throws and heaps up the larger pieces of charcoal into that part of the hearth which is against the little wall which protects the other wall from injury by fire, and partly extinguishes them by pouring water over them. The master, with a hazel stick inserted into the crucible, stirs it twice. Afterward he draws off the slags with a rabble, which consists of an iron blade, wide and sharp, and of alder-wood; the blade is a digit and a half in width and three feet long; the wooden handle inserted in its hollow part is the same number of feet long, and the alder-wood in which the blade is fixed must have the figure of a rhombus; it must be three palms and a digit long, a palm and two digits wide, and a palm thick. Subsequently he takes a broom and sweeps the charcoal dust and small coal over the whole of the crucible, lest the copper should cool before it flows together; then, with a third rabble, he cuts off the slags which may adhere to the edge of the crucible. The blade of this rabble is two palms long and a palm and one digit wide, the iron part of the handle is a foot and three palms long, the wooden part six feet. Afterward he again draws off the slags from the crucible, which the assistant does not quench by pouring water upon them, as the other slags are usually quenched, but he sprinkles over them a little water and allows them to cool. If the copper should bubble, he presses down the bubbles with the rabble. Then he pours water on the wall and the pipes, that it may flow down warm into the crucible, for, the copper, if cold water were to be poured over it while still hot, would spatter about. If a stone, or a piece of lute or wood, or a damp coal should then fall into it, the crucible would vomit out all the copper with a loud noise like thunder, and whatever it touches it injures and sets on fire.
The bellows which this master uses differ in size from the others, for the boards are seven and a half feet long; the back part is three feet wide; the front, where the head is joined on is a foot, two palms and as many digits. The head is a cubit and a digit long; the back part of it is a cubit and a palm wide, and then becomes gradually narrower. The nozzles of the bellows are bound together by means of an iron chain, controlled by a thick bar, one end of which penetrates into the ground against the back of the long wall, and the other end passes under the beam which is laid upon the foremost perforated beams. These nozzles are so placed in a copper pipe that they are at a distance of a palm from the mouth; the mouth should be made three digits in diameter, that the air may be violently expelled through this narrow aperture.
There now remain the liquation thorns, the ash-coloured copper, the "slags," and the cadmia.[27] Liquation cakes are made from thorns in the following manner.[28] There are taken three-quarters of a centumpondium of thorns, which have their origin from the cakes of copper-lead alloy when lead-silver is liquated, and as many parts of a centumpondium of the thorns derived from cakes made from once re-melted thorns by the same method, and to them are added a centumpondium of de-silverized lead and half a centumpondium of hearth-lead. If there is in the works plenty of litharge, it is substituted for the de-silverized lead. One and a half centumpondia of litharge and hearth-lead is added to the same weight of primary thorns, and half a centumpondium of thorns which have their origin from liquation cakes composed of thorns twice re-melted by the same method (tertiary thorns), and a fourth part of a centumpondium of thorns which are produced when the exhausted liquation cakes are "dried." By both methods one single liquation cake is made from three centumpondia. In this manner the smelter makes every day fifteen liquation cakes, more or less; he takes great care that the metallic substances, from which the first liquation cake is made, flow down properly and in due order into the forehearth, before the material of which the subsequent cake is to be made. Five of these liquation cakes are put simultaneously into the furnace in which silver-lead is liquated from copper, they weigh almost fourteen centumpondia, and the "slags" made therefrom usually weigh quite a centumpondium. In all the liquation cakes together there is usually one libra and nearly two unciae of silver, and in the silver-lead which drips from those cakes, and weighs seven and a half centumpondia, there is in each an uncia and a half of silver. In each of the three centumpondia of liquation thorns there is almost an uncia of silver, and in the two centumpondia and a quarter of exhausted liquation cakes there is altogether one and a half unciae; yet this varies greatly for each variety of thorns, for in the thorns produced from primary liquation cakes made of copper and lead when silver-lead is liquated from the copper, and those produced in "drying" the exhausted liquation cakes, there are almost two unciae of silver; in the others not quite an uncia. There are other thorns besides, of which I will speak a little further on.
Those in the Carpathian Mountains who make liquation cakes from the copper "bottoms" which remain after the upper part of the copper is divided from the lower, in the furnace similar to an oven, produce thorns when the poor or mediocre silver-lead is liquated from the copper. These, together with those made of cakes of re-melted thorns, or made with re-melted litharge, are placed in a heap by themselves; but those that are made from cakes melted from hearth-lead are placed in a heap separate from the first, and likewise those produced from "drying" the exhausted liquation cakes are placed separately; from these thorns liquation cakes are made. From the first heap they take the fourth part of a centumpondium, from the second the same amount, from the third a centumpondium,—to which thorns are added one and a half centumpondia of litharge and half a centumpondium of hearth-lead, and from these, melted in the blast furnace, a liquation cake is made; each workman makes twenty such cakes every day. But of theirs enough has been said for the present; I will return to ours.
The ash-coloured copper[29] which is chipped off, as I have stated, from the "dried" cakes, used some years ago to be mixed with the thorns produced from liquation of the copper-lead alloy, and contained in themselves, equally with the first, two unciae of silver; but now it is mixed with the concentrates washed from the accretions and the other material. The inhabitants of the Carpathian Mountains melt this kind of copper in furnaces in which are re-melted the "slags" which flow out when the copper is refined; but as this soon melts and flows down out of the furnace, two workmen are required for the work of smelting, one of whom smelts, while the other takes out the thick cakes from the forehearth. These cakes are only "dried," and from the "dried" cakes copper is again made.
The "slags"[30] are melted continually day and night, whether they have been drawn off from the alloyed metals with a rabble, or whether they adhered to the forehearth to the thickness of a digit and made it smaller and were taken off with spatulas. In this manner two or three liquation cakes are made, and afterward much or little of the "slag," skimmed from the molten alloy of copper and lead, is re-melted. Such liquation cakes should weigh up to three centumpondia, in each of which there is half an uncia of silver. Five cakes are placed at the same time in the furnace in which argentiferous lead is liquated from copper, and from these are made lead which contains half an uncia of silver to the centumpondium. The exhausted liquation cakes are laid upon the other baser exhausted liquation cakes, from both of which yellow copper is made. The base thorns thus obtained are re-melted with a few baser "slags," after having been sprinkled with concentrates from furnace accretions and other material, and in this manner six or seven liquation cakes are made, each of which weighs some two centumpondia. Five of these are placed at the same time in the furnace in which silver-lead is liquated from copper; these drip three centumpondia of lead, each of which contains half an uncia of silver. The basest thorns thus produced should be re-melted with only a little "slag." The copper alloyed with lead, which flows down from the furnace into the forehearth, is poured out with a ladle into oblong copper moulds; these cakes are "dried" with base exhausted liquation cakes. The thorns they produce are added to the base thorns, and they are made into cakes according to the method I have described. From the "dried" cakes they make copper, of which some add a small portion to the best "dried" cakes when copper is made from them, in order that by mixing the base copper with the good it may be sold without loss. The "slags," if they are utilisable, are re-melted a second and a third time, the cakes made from them are "dried," and from the "dried" cakes is made copper, which is mixed with the good copper. The "slags," drawn off by the master who makes copper out of "dried" cakes, are sifted, and those which fall through the sieve into a vessel placed underneath are washed; those which remain in it are emptied into a wheelbarrow and wheeled away to the blast furnaces, and they are re-melted together with other "slags," over which are sprinkled the concentrates from washing the slags or furnace accretions made at this time. The copper which flows out of the furnace into the forehearth, is likewise dipped out with a ladle into oblong copper moulds; in this way nine or ten cakes are made, which are "dried," together with bad exhausted liquation cakes, and from these "dried" cakes yellow[31] copper is made.