of the bellows, and blows up the fire with the bellows ; thus within the space
of half an hour the forehearth, as well as the hearth, becomes warmed, and
of course more quickly if on the preceding day ores have been smelted in the
same furnace, but if not then it warms more slowly. If the hearth and
forehearth are not warmed before the ore to be smelted is thrown in, the furnace
is injured and the metals lost ; or if the powder from which both are made
is damp in summer or frozen in winter, they will be cracked, and, giving
out a sound like thunder, they will blow out the metals and other substances
with great peril to the workmen. After the furnace has been warmed, the
master throws in slags, and these, when melted, flow out through the taphole into the forehearth. Then he closes up the tap-hole at once with
mixed lute and charcoal dust ; this plug he fastens with his hand to a
round wooden rammer that is five digits thick, two palms high, with a handle
three feet long. The smelter extracts the slags from the forehearth with a
hooked bar ; if the ore to be smelted is rich in gold or silver he puts into the
forehearth a centumpondium of lead, or half as much if the ore is poor,
because the former requires much lead, the latter little ; he immediately
throws burning firebrands on to the lead so that it melts. Afterward he
performs everything according to the usual manner and order, whereby he
first throws into the furnace as many cakes melted from pyrites12, as he
requires to smelt the ore ; then he puts in two wicker baskets full of ore
with litharge and hearth-lead13, and stones which fuse easily by fire of the
second order, all mixed together ; then one wicker basket full of charcoal,
and lastly the slags. The furnace now being filled with all the things I
have mentioned, the ore is slowly smelted ; he does not put too much of it
against the back wall of the furnace, lest sows should form around the nozzles
of the bellows and the blast be impeded and the fire burn less fiercely.
This, indeed, is the custom of many most excellent smelters, who know
how to govern the four elements14. They combine in right proportion the
ores, 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 air
from the bellows ; they throw the ore into that part of the fire which burns
fiercely. The master sprinkles water into each part of the furnace to dampen
the 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 agitate
and blow away with the fumes. But as the nature of the ores to be smelted
varies, the smelters have to arrange the hearth now high, now low, and to
place the pipe in which the nozzles of the bellows are inserted sometimes on a
great and sometimes at a slight angle, so that the blast of the bellows may
uPanes ex pyrite conflati. While the term matte would cover most cases where this
expression appears, and in many cases would be more expressive to the modern reader, yet
there^are instances where the expression as it stands indicates its particular origin, and it
has been, therefore, considered advisable to adhere to the literal rendering.
aMolybdaena. See note 37, p. 476. It was the saturated furnace bottoms from
cupellation.
"The four elements were earth, air, fire, and water.
