1forehearth pit is full,
then afterward this is hollowed out with a curved
blade; this blade is of iron, two palms and as many digits long, three digits
wide, blunt at the top and sharp at the bottom. The crucible of the fore
hearth must be round, a foot in diameter and two palms deep if it has to
contain a centumpondíum of lead, or if only seventy líbrae, then three palms
in diameter and two palms deep like the other. When the forehearth has
been hollowed out it is pounded with a round bronze rammer. This is
five digits high and the same in diameter, having a curved round handle
one and a half digits thick; or else another bronze rammer is used, which
is fashioned in the shape of a cone, truncated at the top, on which is
imposed another cut away at the bottom, so that the middle part of the
rammer may be grasped by the hand; this is six digits high, and five digits
in diameter at the lower end and four at the top. Some use in its place a
wooden spatula two and a half palms wide at the lower end and one palm
thick.
blade; this blade is of iron, two palms and as many digits long, three digits
wide, blunt at the top and sharp at the bottom. The crucible of the fore
hearth must be round, a foot in diameter and two palms deep if it has to
contain a centumpondíum of lead, or if only seventy líbrae, then three palms
in diameter and two palms deep like the other. When the forehearth has
been hollowed out it is pounded with a round bronze rammer. This is
five digits high and the same in diameter, having a curved round handle
one and a half digits thick; or else another bronze rammer is used, which
is fashioned in the shape of a cone, truncated at the top, on which is
imposed another cut away at the bottom, so that the middle part of the
rammer may be grasped by the hand; this is six digits high, and five digits
in diameter at the lower end and four at the top. Some use in its place a
wooden spatula two and a half palms wide at the lower end and one palm
thick.
The assistant, having prepared the forehearth, returns to the furnace and
besmears both sides as well as the top of the mouth with simple lute. In the
lower part of the mouth he places lute that has been dipped in charcoal
dust, to guard against the risk of the lute attracting to itself the powder
of the hearth and vitiating it. Next he lays in the mouth of the furnace a
straight round rod three quarters of a foot long and three digits in diameter.
Afterward he places a piece of charcoal on the lute, of the same length and
width as the mouth, so that it is entirely closed up; if there be not at hand
one piece of charcoal so large, he takes two instead. When the mouth is thus
closed up, he throws into the furnace a wicker basket full of charcoal, and in
order that the piece of charcoal with which the mouth of the furnace is closed
should not then fall out, the master holds it in with his hand. The pieces
of charcoal which are thrown into the furnace should be of medium size, for
if they are large they impede the blast of the bellows and prevent it from
blowing through the tap-hole of the furnace into the forehearth to heat it.
Then the master covers over the charcoal, placed at the mouth of the furnace,
with lute and extracts the wooden rod, and thus the furnace is prepared.
Afterward the assistant throws four or five larger baskets full of charcoal
into the furnace, filling it right up; he also throws a little charcoal
into the forehearth, and places glowing coals upon it in order that it may
be kindled, but in order that the flames of this fire should not enter through
the tap-hole of the furnace and fire the charcoal inside, he covers the tap-hole
with lute or closes it with fragments of pottery. Some do not warm the
forehearth the same evening, but place large charcoals round the edge of it, one
leaning on the other; those who follow the first method sweep out the
forehearth in the morning, and clean out the little pieces of charcoal and
cinders, while those who follow the latter method take, early in the morning,
burning firebrands, which have been prepared by the watchman of the works,
and place them on the charcoal.
besmears both sides as well as the top of the mouth with simple lute. In the
lower part of the mouth he places lute that has been dipped in charcoal
dust, to guard against the risk of the lute attracting to itself the powder
of the hearth and vitiating it. Next he lays in the mouth of the furnace a
straight round rod three quarters of a foot long and three digits in diameter.
Afterward he places a piece of charcoal on the lute, of the same length and
width as the mouth, so that it is entirely closed up; if there be not at hand
one piece of charcoal so large, he takes two instead. When the mouth is thus
closed up, he throws into the furnace a wicker basket full of charcoal, and in
order that the piece of charcoal with which the mouth of the furnace is closed
should not then fall out, the master holds it in with his hand. The pieces
of charcoal which are thrown into the furnace should be of medium size, for
if they are large they impede the blast of the bellows and prevent it from
blowing through the tap-hole of the furnace into the forehearth to heat it.
Then the master covers over the charcoal, placed at the mouth of the furnace,
with lute and extracts the wooden rod, and thus the furnace is prepared.
Afterward the assistant throws four or five larger baskets full of charcoal
into the furnace, filling it right up; he also throws a little charcoal
into the forehearth, and places glowing coals upon it in order that it may
be kindled, but in order that the flames of this fire should not enter through
the tap-hole of the furnace and fire the charcoal inside, he covers the tap-hole
with lute or closes it with fragments of pottery. Some do not warm the
forehearth the same evening, but place large charcoals round the edge of it, one
leaning on the other; those who follow the first method sweep out the
forehearth in the morning, and clean out the little pieces of charcoal and
cinders, while those who follow the latter method take, early in the morning,
burning firebrands, which have been prepared by the watchman of the works,
and place them on the charcoal.
At the fourth hour the master begins his work.
He first inserts a
small piece of glowing coal into the furnace, through the bronze nozzle-pipe
small piece of glowing coal into the furnace, through the bronze nozzle-pipe