1and it is
nearly as long as the furnace; only at the front end does it touch
the mouth of the furnace, everywhere else on the sides and at the back
there is a space of three digits, to allow the charcoal to lie in the open space
between it and the furnace. The muffle is as thick as a fairly thick earthen
jar; its upper part is entire; the back has two little windows, and each side
has two or three or even four, through which the heat passes into the scorifiers
and melts the ore. In place of little windows, some muffles have small holes,
ten in the back and more on each side. Moreover, in the back below the
little windows, or small holes, there are cut away three semi-circular notches
half a digit high, and on each side there are four. The back of the muffle
is generally a little lower than the front.
the mouth of the furnace, everywhere else on the sides and at the back
there is a space of three digits, to allow the charcoal to lie in the open space
between it and the furnace. The muffle is as thick as a fairly thick earthen
jar; its upper part is entire; the back has two little windows, and each side
has two or three or even four, through which the heat passes into the scorifiers
and melts the ore. In place of little windows, some muffles have small holes,
ten in the back and more on each side. Moreover, in the back below the
little windows, or small holes, there are cut away three semi-circular notches
half a digit high, and on each side there are four. The back of the muffle
is generally a little lower than the front.
A—BROAD LITTLE WINDOWS OF MUFFLE. B—NARROW ONES. C—OPENINGS
IN THE
BACK THEREOF.
BACK THEREOF.
The crucibles differ in the materials from which they are made, because
they are made of either clay or ashes; and those of clay, which we also call
“earthen,” differ in shape and size. Some are made in the shape of a mod
erately thick salver (scorifiers), three digits wide, and of a capacity of an
uncía measure; in these the ore mixed with fluxes is melted, and they are used
by those who assay gold or silver ore. Some are triangular and much
thicker and more capacious, holding five, or six, or even more uncíae; in
these copper is melted, so that it can be poured out, expanded, and tested
with fire, and in these copper ore is usually melted.
they are made of either clay or ashes; and those of clay, which we also call
“earthen,” differ in shape and size. Some are made in the shape of a mod
erately thick salver (scorifiers), three digits wide, and of a capacity of an
uncía measure; in these the ore mixed with fluxes is melted, and they are used
by those who assay gold or silver ore. Some are triangular and much
thicker and more capacious, holding five, or six, or even more uncíae; in
these copper is melted, so that it can be poured out, expanded, and tested
with fire, and in these copper ore is usually melted.
The cupels are made of ashes; like the preceding scorifiers they are
tray-shaped, and their lower part is very thick but their capacity is less.
In these lead is separated from silver, and by them assays are concluded.
Inasmuch as the assayers themselves make the cupels, something must
be said about the material from which they are made, and the method
of making them. Some make them out of all kinds of ordinary ashes; these
are not good, because ashes of this kind contain a certain amount of fat,
whereby such cupels are easily broken when they are hot. Others make
them likewise out of any kind of ashes which have been previously
leached; of this kind are the ashes into which warm water has been infused
for the purpose of making lye. These ashes, after being dried in the sun or
a furnace, are sifted in a hair sieve; and although warm water washes away the
tray-shaped, and their lower part is very thick but their capacity is less.
In these lead is separated from silver, and by them assays are concluded.
Inasmuch as the assayers themselves make the cupels, something must
be said about the material from which they are made, and the method
of making them. Some make them out of all kinds of ordinary ashes; these
are not good, because ashes of this kind contain a certain amount of fat,
whereby such cupels are easily broken when they are hot. Others make
them likewise out of any kind of ashes which have been previously
leached; of this kind are the ashes into which warm water has been infused
for the purpose of making lye. These ashes, after being dried in the sun or
a furnace, are sifted in a hair sieve; and although warm water washes away the
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