1of the bellows.
The whole of the front furnace wall is not more than five feet
high, so that the ore may be conveniently put into the furnace, together with
those things which the master needs for his work of smelting. Both the side
walls of the furnace are six feet high, and the back one seven feet, and they
are three palms thick. The interior of the furnace is five palms wide, six
palms and a digit long, the width being measured by the space which lies
between the two side walls, and the length by the space between the front and
the back walls; however, the upper part of the furnace widens out somewhat.
high, so that the ore may be conveniently put into the furnace, together with
those things which the master needs for his work of smelting. Both the side
walls of the furnace are six feet high, and the back one seven feet, and they
are three palms thick. The interior of the furnace is five palms wide, six
palms and a digit long, the width being measured by the space which lies
between the two side walls, and the length by the space between the front and
the back walls; however, the upper part of the furnace widens out somewhat.
There are two doors in the second wall if there are six furnaces, one
of the doors being between the second and third furnaces and the other
between the fourth and fifth furnaces. They are a cubit wide and six feet
high, in order that the smelters may not have mishaps in coming and going.
It is necessary to have a door to the right of the first furnace, and similarly
one to the left of the last, whether the wall is longer or not. The second
wall is carried further when the rooms for the cupellation furnaces, or any
other building, adjoin the rooms for the blast furnaces, these buildings being
only divided by a partition. The smelter, and the ones who attend to the
first and the last furnaces, if they wish to look at the bellows or to do anything
else, go out through the doors at the end of the wall, and the other people go
through the other doors, which are the common ones. The furnaces are placed
at a distance of six feet from one another, in order that the smelters and their
assistants may more easily sustain the fierceness of the heat. Inasmuch as
the interior of each furnace is five palms wide and each is six feet distant
from the other, and inasmuch as there is a space of four feet three palms at
the right side of the first furnace and as much at the left side of the last
furnace, and there are to be six furnaces in one building, then it is necessary
to make the second wall fifty-two feet long; because the total of the widths
of all of the furnaces is seven and a half feet, the total of the spaces between
the furnaces is thirty feet, the space on the outer sides of the first and last
furnaces is nine feet and two palms, and the thickness of the two transverse
walls is five feet, which make a total measurement of fifty-two feet.3
of the doors being between the second and third furnaces and the other
between the fourth and fifth furnaces. They are a cubit wide and six feet
high, in order that the smelters may not have mishaps in coming and going.
It is necessary to have a door to the right of the first furnace, and similarly
one to the left of the last, whether the wall is longer or not. The second
wall is carried further when the rooms for the cupellation furnaces, or any
other building, adjoin the rooms for the blast furnaces, these buildings being
only divided by a partition. The smelter, and the ones who attend to the
first and the last furnaces, if they wish to look at the bellows or to do anything
else, go out through the doors at the end of the wall, and the other people go
through the other doors, which are the common ones. The furnaces are placed
at a distance of six feet from one another, in order that the smelters and their
assistants may more easily sustain the fierceness of the heat. Inasmuch as
the interior of each furnace is five palms wide and each is six feet distant
from the other, and inasmuch as there is a space of four feet three palms at
the right side of the first furnace and as much at the left side of the last
furnace, and there are to be six furnaces in one building, then it is necessary
to make the second wall fifty-two feet long; because the total of the widths
of all of the furnaces is seven and a half feet, the total of the spaces between
the furnaces is thirty feet, the space on the outer sides of the first and last
furnaces is nine feet and two palms, and the thickness of the two transverse
walls is five feet, which make a total measurement of fifty-two feet.3
Outside each furnace hearth there is a small pit full of powder which is
compressed by ramming, and in this manner is made the forehearth which
receives the metal flowing from the furnaces. Of this I will speak later.
compressed by ramming, and in this manner is made the forehearth which
receives the metal flowing from the furnaces. Of this I will speak later.
Buried about a cubit under the forehearth and the hearth of the furnace
is a transverse water-tank, three feet long, three palms wide and a cubit deep.
It is made of stone or brick, with a stone cover, for if it were not covered, the
heat would draw the moisture from below and the vapour might be blown
into the hearth of the furnace as well as into the forehearth, and would
dampen the blast. The moisture would vitiate the blast, and part of the
metal would be absorbed and part would be mixed with the slags, and in
this manner the melting would be greatly damaged. From each water-tank
is built a walled vent, to the same depth as the tank, but six digits wide;
is a transverse water-tank, three feet long, three palms wide and a cubit deep.
It is made of stone or brick, with a stone cover, for if it were not covered, the
heat would draw the moisture from below and the vapour might be blown
into the hearth of the furnace as well as into the forehearth, and would
dampen the blast. The moisture would vitiate the blast, and part of the
metal would be absorbed and part would be mixed with the slags, and in
this manner the melting would be greatly damaged. From each water-tank
is built a walled vent, to the same depth as the tank, but six digits wide;