1in slags, the uppermost
containing little metal, the middle more, and the
lowest much, he puts these away separately, each in its own place, in
order that to each heap, when it is re-smelted, he may add the proper
fluxes, and can put in as much lead as is demanded for the metal in the
slag; when the slag is re-melted, if it emits much odour, there is some
metal in it; if it emits no odour, then it contains none. He puts the cakes
of melted pyrites away separately, as they were nearest in the forehearth to
the metal, and contain a little more of it than the slags; from all these
cakes a conical mound is built up, by always placing the widest of them
at the bottom. The hooked bar has a hook on the end, hence its name;
otherwise it is similar to other bars.
lowest much, he puts these away separately, each in its own place, in
order that to each heap, when it is re-smelted, he may add the proper
fluxes, and can put in as much lead as is demanded for the metal in the
slag; when the slag is re-melted, if it emits much odour, there is some
metal in it; if it emits no odour, then it contains none. He puts the cakes
of melted pyrites away separately, as they were nearest in the forehearth to
the metal, and contain a little more of it than the slags; from all these
cakes a conical mound is built up, by always placing the widest of them
at the bottom. The hooked bar has a hook on the end, hence its name;
otherwise it is similar to other bars.
Afterward the master closes up the tap-hole and fills the furnace with
the same materials I described above, and again, the ores having been melted,
he opens the tap-hole, and with a hooked bar extracts the slags and the cakes
melted from pyrites, which have run down into the forehearth. He repeats
the same operation until a certain and definite part of the ore has been
smelted, and the day's work is at an end; if the ore was rich the work is
finished in eight hours; if poor, it takes a longer time. But if the ore was
so rich as to be smelted in less than eight hours, another operation is in the
meanwhile combined with the first, and both are performed in the space of ten
hours. When all the ore has been smelted, he throws into the furnace a
basket full of litharge or hearth-lead, so that the metal which has remained
in the accretions may run out with these when melted. When he has finally
drawn out of the forehearth the slags and the cakes melted from pyrites,
he takes out, with a ladle, the lead alloyed with gold or silver and pours it into
little iron or copper pans, three palms wide and as many digits deep, but
first lined on the inside with lute and dried by warming, lest the glowing molten
substances should break through. The iron ladle is two palms wide, and in
other respects it is similar to the others, all of which have a sufficiently long
iron shaft, so that the fire should not burn the wooden part of the handle.
When the alloy has been poured out of the forehearth, the smelter foreman
and the mine captain weigh the cakes.
the same materials I described above, and again, the ores having been melted,
he opens the tap-hole, and with a hooked bar extracts the slags and the cakes
melted from pyrites, which have run down into the forehearth. He repeats
the same operation until a certain and definite part of the ore has been
smelted, and the day's work is at an end; if the ore was rich the work is
finished in eight hours; if poor, it takes a longer time. But if the ore was
so rich as to be smelted in less than eight hours, another operation is in the
meanwhile combined with the first, and both are performed in the space of ten
hours. When all the ore has been smelted, he throws into the furnace a
basket full of litharge or hearth-lead, so that the metal which has remained
in the accretions may run out with these when melted. When he has finally
drawn out of the forehearth the slags and the cakes melted from pyrites,
he takes out, with a ladle, the lead alloyed with gold or silver and pours it into
little iron or copper pans, three palms wide and as many digits deep, but
first lined on the inside with lute and dried by warming, lest the glowing molten
substances should break through. The iron ladle is two palms wide, and in
other respects it is similar to the others, all of which have a sufficiently long
iron shaft, so that the fire should not burn the wooden part of the handle.
When the alloy has been poured out of the forehearth, the smelter foreman
and the mine captain weigh the cakes.
Then the master breaks out the whole of the mouth of the furnace with a
crowbar, and with that other hooked bar, the rabble and the five-toothed rake,
he extracts the accretions and the charcoal. This crowbar is not unlike
the other hooked one, but larger and wider; the handle of the rabble is six feet
long and is half of iron and half of wood. The furnace having cooled, the
master chips off the accretions clinging to the walls with a rectangular
spatula six digits long, a palm broad, and sharp on the front edge; it has
a round handle four feet long, half of it being of iron and half of wood. This
is the first method of smelting ores.
crowbar, and with that other hooked bar, the rabble and the five-toothed rake,
he extracts the accretions and the charcoal. This crowbar is not unlike
the other hooked one, but larger and wider; the handle of the rabble is six feet
long and is half of iron and half of wood. The furnace having cooled, the
master chips off the accretions clinging to the walls with a rectangular
spatula six digits long, a palm broad, and sharp on the front edge; it has
a round handle four feet long, half of it being of iron and half of wood. This
is the first method of smelting ores.
Because they generally consist of unequal constituents, some of which melt
rapidly and others slowly, the ores rich in gold and silver cannot be smelted as
rapidly or as easily by the other methods as they can by the first method, for
three important reasons. The first reason is that, as often as the closed
tap-hole of the furnace is opened with a tapping-bar, so often can the
rapidly and others slowly, the ores rich in gold and silver cannot be smelted as
rapidly or as easily by the other methods as they can by the first method, for
three important reasons. The first reason is that, as often as the closed
tap-hole of the furnace is opened with a tapping-bar, so often can the
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