Those ingredients above are peculiar to each cement, but what follows
is common to all. Each of the ingredients is first separately crushed to
powder; the bricks are placed on a hard rock or marble, and crushed with an
iron implement; the other things are crushed in a mortar with a pestle;
each is separately passed through a sieve. Then they are all mixed together,
and are moistened with vinegar in which a little sal-ammoniac has been
dissolved, if the cement does not contain any. But some workers, however,
prefer to moisten the gold granules or gold-leaf instead.
is common to all. Each of the ingredients is first separately crushed to
powder; the bricks are placed on a hard rock or marble, and crushed with an
iron implement; the other things are crushed in a mortar with a pestle;
each is separately passed through a sieve. Then they are all mixed together,
and are moistened with vinegar in which a little sal-ammoniac has been
dissolved, if the cement does not contain any. But some workers, however,
prefer to moisten the gold granules or gold-leaf instead.
The cement should be placed, alternately with the gold, in new and clean
pots in which no water has ever been poured. In the bottom the cement is
levelled with an iron implement, and afterward the gold granules or leaves
are placed one against the other, so that they may touch it on all sides; then,
again, a handful of the cement, or more if the pots are large, is thrown in and
levelled with an iron implement; the granules and leaves are laid over this
in the same manner, and this is repeated until the pot is filled. Then it is
covered with a lid, and the place where they join is smeared over with
artificial lute, and when this is dry the pots are placed in the furnace.
pots in which no water has ever been poured. In the bottom the cement is
levelled with an iron implement, and afterward the gold granules or leaves
are placed one against the other, so that they may touch it on all sides; then,
again, a handful of the cement, or more if the pots are large, is thrown in and
levelled with an iron implement; the granules and leaves are laid over this
in the same manner, and this is repeated until the pot is filled. Then it is
covered with a lid, and the place where they join is smeared over with
artificial lute, and when this is dry the pots are placed in the furnace.
The furnace has three chambers, the lowest of which is a foot high; into
this lowest chamber the air penetrates through an opening, and into it the
this lowest chamber the air penetrates through an opening, and into it the
A—FURNACE. B—POT. C—LID. D—AIR-HOLES.