1muffle has small windows at the sides, and in front a
little bridge.
In order
to melt the silver, at the sides of the muffle are laid bricks, upon which the
charcoal is placed, and burning firebrands are put on the bridge. The
furnace has an iron door, which is covered on the side next to the fire with lute
in order that it may not be injured. When the door is closed it retains the
heat of the fire, but it has a small window, so that the artificers may look
into the test and may at times stimulate the fire with the bellows. Although
by this method silver is refined more slowly than by the other, nevertheless it is
more useful, because less loss is caused, for a gentle fire consumes fewer particles
than a fierce fire continually excited by the blast of the bellows. If, on
account of its great size, the cake of silver can be carried only with difficulty
when it is taken out of the muffle, they cut it up into two or three
pieces while it is still hot, with a wedge or a hammer-chisel; for if they cut
it up after it has cooled, little pieces of it frequently fly off and are lost.
to melt the silver, at the sides of the muffle are laid bricks, upon which the
charcoal is placed, and burning firebrands are put on the bridge. The
furnace has an iron door, which is covered on the side next to the fire with lute
in order that it may not be injured. When the door is closed it retains the
heat of the fire, but it has a small window, so that the artificers may look
into the test and may at times stimulate the fire with the bellows. Although
by this method silver is refined more slowly than by the other, nevertheless it is
more useful, because less loss is caused, for a gentle fire consumes fewer particles
than a fierce fire continually excited by the blast of the bellows. If, on
account of its great size, the cake of silver can be carried only with difficulty
when it is taken out of the muffle, they cut it up into two or three
pieces while it is still hot, with a wedge or a hammer-chisel; for if they cut
it up after it has cooled, little pieces of it frequently fly off and are lost.
END OF BOOK X.