DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.19571#0218
2o4 THE ARTIST'S ASSISTANT.
The preparation of Mantua earth, for moulds: —
Take Mantua earth one part, and one part of charcoal
duft of burnt birch, and one part of fait ; then mix
with it an equal quantity of tartar; boil up the mix-
ture together in a copper pan, and let. it feeth three
times; with this water, which keeps always good,
moiften and temper your earth, fo as to form it into
balls between your hands, and when you would
make your mould, roll your earth with a roller, till
it is fmooth and pliable, then you may form it into
what fafhion you plea'e. In this mould you may
caft before it is dried; and when you have caft,
take off the earth which is dried through the heat
O
of the metal, grind the fame again, and temper it
as you did at fir ft to ufe it again.
A particular fort of mould, in which one may
caft exceedingly fine:—Take horfe mufcles, or for
want of them cyfter fhells, let them be calcined m
a potter's furnace, then pulverize and temper them
with urine; of this make your moulds, and you
will caft very fine and fharp.
To imprefs bafs relievo or medals, in imitation of
ivorv. —Take of prepared clay one pound, fine plaifter
of Paris eight ounces, white ftarch eight ounces, mix
thefe together, and beat up the mixture with the
white of fix or eight eggs, put to it three ounces of
clear gum arabic, ftir it well together to a palle,
and put fo much of the dry mixture to it, till you
knead it like dough ; then prefs it into a mould with
the palm of your hand, and let it dry in the fun, ob-
fervingto lay the pafte fide on a fmooth board, and it
will be clear and hard, like ivory. \ ou may im-
prefs all manner of medals and curiofities, and make
them of what colour you pleafe.
To
The preparation of Mantua earth, for moulds: —
Take Mantua earth one part, and one part of charcoal
duft of burnt birch, and one part of fait ; then mix
with it an equal quantity of tartar; boil up the mix-
ture together in a copper pan, and let. it feeth three
times; with this water, which keeps always good,
moiften and temper your earth, fo as to form it into
balls between your hands, and when you would
make your mould, roll your earth with a roller, till
it is fmooth and pliable, then you may form it into
what fafhion you plea'e. In this mould you may
caft before it is dried; and when you have caft,
take off the earth which is dried through the heat
O
of the metal, grind the fame again, and temper it
as you did at fir ft to ufe it again.
A particular fort of mould, in which one may
caft exceedingly fine:—Take horfe mufcles, or for
want of them cyfter fhells, let them be calcined m
a potter's furnace, then pulverize and temper them
with urine; of this make your moulds, and you
will caft very fine and fharp.
To imprefs bafs relievo or medals, in imitation of
ivorv. —Take of prepared clay one pound, fine plaifter
of Paris eight ounces, white ftarch eight ounces, mix
thefe together, and beat up the mixture with the
white of fix or eight eggs, put to it three ounces of
clear gum arabic, ftir it well together to a palle,
and put fo much of the dry mixture to it, till you
knead it like dough ; then prefs it into a mould with
the palm of your hand, and let it dry in the fun, ob-
fervingto lay the pafte fide on a fmooth board, and it
will be clear and hard, like ivory. \ ou may im-
prefs all manner of medals and curiofities, and make
them of what colour you pleafe.
To