it is twenty feet long, and starts from the fourth long wall. The sixth
transverse wall is built also from the fourth long wall, at a point distant
thirty feet from the fourth transverse wall, and it extends as far as the back
of the third long wall. The seventh transverse wall is constructed from
the second long wall, where this first leaves off, to the third long wall ; and
from the back of the third long wall the eighth transverse wall is built,
extending to the end of the fourth long wall. Then the fifth long wall is built
from the seventh transverse wall, starting at a point nineteen feet from the
second long wall ; it is one hundred and nine feet in length ; and at a point
twenty-four feet along it, the ninth transverse wall is carried to the third end
of the second long wall, where that begins again. The tenth transverse wall is
built from the end of the fifth long wall, and leads to the further end of the
second long wall ; and from there the eleventh transverse wall leads to the
further end of the first long wall. Behind the fifth long wall, and five feet
toward the third long wall, the sixth long wall is built, leading from the
seventh transverse wall ; its length is thirty-five feet, and from its further
end the twelfth transverse wall is built to the third long wall, and from it the
thirteenth transverse wall is built to the fifth long wall. The fourteenth
transverse wall divides into equal parts the space which lies between the
seventh transverse wall and the twelfth.
The length, height, breadth, and position of the walls are as above.
Their archways, doors, and openings are made at the same time that the walls
are built. The size of these and the way they are made will be much better
understood hereafter. I will now speak of the furnace hoods and of the roofs.
The first side2 of the hood stands on the second long wall, and is similar in
every respect to those whose structure I explained in Book IX, when I
described the works in whose furnaces are smelted the ores of gold, silver,
and copper. From this side of the hood a roof, which consists of burnt tiles,
extends to the first long wall ; and this part of the building contains the
bellows, the machinery for compressing them, and the instruments for
inflating them. In the middle space, which is situated between the second
and third transverse walls, an upright post eight feet high and two feet thick
Historical Note.—So far as we are aware, this is the first complete discussion
of this process, although it is briefly mentioned by one writer before Agricola—that is, by
Biringuccio (in, 5, 8), who wrote ten years before this work was sent to the printer. His
account is very incomplete, for he describes only the bare liquation, and states that the copper
is re-melted with lead and re-liquated until the silver is sufficiently abstracted. He neither
mentions " drying " nor any of the bye-products. In his directions the silver-lead alloy was
cupelled and the copper ultimately refined, obviously by oxidation and poling, although he
omits the pole. In a.d. 1150 Theophilus (p. 305, Hendrie's Trans.) describes melting lead
out of copper ore, which would be a form of liquation so far as separation of these two metals
is concerned, but obviously not a process for separating silver from copper. This passage is
quoted in the note on copper smelting (Note on p. 405). A process of such well-developed and
complicated a character must have come from a period long before Agricola ; but further than
such a surmise, there appears little to be recorded. Liquation has been during the last fifty
years displaced by other methods, because it was not only tedious and expensive, but the
losses of metal were considerable.
Varies,—" Partition " or " wall." The author uses this term throughout in
distinction to murus, usually applying the latter to the walls of the building and the former to
furnace walls, chimney walls, etc. In order to gain clarity, we have introduced the term
" hood " in distinction to " chimney," and so far as possible refer to the paries of these constructions and furnaces as " side of the furnace," " side of the hood," etc.
