1are folded together.
Since this kind of bellows does not give a vigorous blast,
because they are drawn apart and compressed slowly, the smelter is not
able during a whole day to smelt much more than half a centumpondium of
tin.
because they are drawn apart and compressed slowly, the smelter is not
able during a whole day to smelt much more than half a centumpondium of
tin.
Very good iron ore is smelted55 in a
furnace almost like the cupellation
furnace. The hearth is three and a half feet high, and five feet long and
wide; in the centre of it is a crucible a foot deep and one and a half feet
wide, but it may be deeper or shallower, wider or narrower, according to whether
more or less ore is to be made into iron. A certain quantity of iron ore is
given to the master, out of which he may smelt either much or little iron.
He being about to expend his skill and labour on this matter, first throws
charcoal into the crucible, and sprinkles over it an iron shovel-ful of crushed
iron ore mixed with unslaked lime. Then he repeatedly throws on charcoal
and sprinkles it with ore, and continues this until he has slowly built up a
heap; it melts when the charcoal has been kindled and the fire violently
stimulated by the blast of the bellows, which are skilfully fixed in a pipe.
furnace. The hearth is three and a half feet high, and five feet long and
wide; in the centre of it is a crucible a foot deep and one and a half feet
wide, but it may be deeper or shallower, wider or narrower, according to whether
more or less ore is to be made into iron. A certain quantity of iron ore is
given to the master, out of which he may smelt either much or little iron.
He being about to expend his skill and labour on this matter, first throws
charcoal into the crucible, and sprinkles over it an iron shovel-ful of crushed
iron ore mixed with unslaked lime. Then he repeatedly throws on charcoal
and sprinkles it with ore, and continues this until he has slowly built up a
heap; it melts when the charcoal has been kindled and the fire violently
stimulated by the blast of the bellows, which are skilfully fixed in a pipe.