DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.20658#0309
ECONOMICAL PAINTING.
295
When the painting is performed in this manner, the glasses are carried to the oven or furnace,
to be annealed or baked. This furnace is made of brick, from twenty-four to thirty inches
square. An aperture is made six inches from the bottom, to receive the fuel; a grate is placed
across the furnace like a flooring, above which is another aperture to admit the pieces of
coloured glass. This grate supports an earthen pan in which the pieces are laid in the following
manner: in the bottom of the pan are placed three strata or layers of .pulverised quick-lime,
separated by layers of old broken glass, to preserve the painted pieces from receiving too much
heat, when they are laid horizontally on the uppermost stratum of quick-lime. Each stratum
of the painted glass is separated from the one above it by a layer of the same powdered quick-
lime, and the uppermost stratum is covered with lime in the same way. The whole furnace is
then covered with a broad flat tile, and closely stopped or luted all round, leaving only a few
small holes to serve for chimnies. The fire for the first two hours should be moderate, but
increased as the annealing or baking goes on, for ten or twelve hours more, when the process
will be finished. At the conclusion of the whole the fire, which at first is made of charcoal, is
made up with live wood, that the flame may surround and cover the pan of glass, Sec. and even
come out at the little chimney-holes.
Trials of the state of the glass are made by taking out pieces placed in the pan for this
purpose, at the small aperture in the furnace; and when the annealing or baking is thought to
be sufficiently advanced, the fire extinguished as speedily as possible, to prevent the glasses from
being broken, and the colours from being burnt, dissipated or changed.
CHAP. VI.
OF ECONOMICAL PAINTING.
THIS branch of painting is very extensive, comprehending the mechanical processes for
preserving and ornamenting walls of houses, furniture, &c. Of the utensils, brushes and
pencils of all sizes are requisite: the brushes ought to be straight, round and smooth; they
should before using be washed some time in warm water, that the wood of the handle may swell
and retain the hairs, which would otherwise be apt to fall off" and adhere to the work. The
brushes are commonly made of boar's bristles, or of a mixture of bristles and hair ; the pencils
are made of badger's hair or other fixed hair in quills of different sizes. The vessels used to
hold the various paints should all be well varnished, to prevent their drying quickly. When the
colours are ground in water they should be diluted in size made from parchment; and when
diluted with spirits of wine no more must be used than what will be necessary for the immediate
occasion, as colours prepared in this way dry rapidly. Colours ground in oil are also diluted
with pure oil, or oil mixed with essence of turpentine, or even with pure turpentine; which makes
them easy to work; but when varnish is added only what is requisite for the moment should be
prepared, as it must be immediately applied. The addition of varnish gives the colours great
brilliancy and dries speedily, but more art is necessary in using them. This part of painting
is divided into water and oil work, with or without the admixture of any varnish..
PAINTING
295
When the painting is performed in this manner, the glasses are carried to the oven or furnace,
to be annealed or baked. This furnace is made of brick, from twenty-four to thirty inches
square. An aperture is made six inches from the bottom, to receive the fuel; a grate is placed
across the furnace like a flooring, above which is another aperture to admit the pieces of
coloured glass. This grate supports an earthen pan in which the pieces are laid in the following
manner: in the bottom of the pan are placed three strata or layers of .pulverised quick-lime,
separated by layers of old broken glass, to preserve the painted pieces from receiving too much
heat, when they are laid horizontally on the uppermost stratum of quick-lime. Each stratum
of the painted glass is separated from the one above it by a layer of the same powdered quick-
lime, and the uppermost stratum is covered with lime in the same way. The whole furnace is
then covered with a broad flat tile, and closely stopped or luted all round, leaving only a few
small holes to serve for chimnies. The fire for the first two hours should be moderate, but
increased as the annealing or baking goes on, for ten or twelve hours more, when the process
will be finished. At the conclusion of the whole the fire, which at first is made of charcoal, is
made up with live wood, that the flame may surround and cover the pan of glass, Sec. and even
come out at the little chimney-holes.
Trials of the state of the glass are made by taking out pieces placed in the pan for this
purpose, at the small aperture in the furnace; and when the annealing or baking is thought to
be sufficiently advanced, the fire extinguished as speedily as possible, to prevent the glasses from
being broken, and the colours from being burnt, dissipated or changed.
CHAP. VI.
OF ECONOMICAL PAINTING.
THIS branch of painting is very extensive, comprehending the mechanical processes for
preserving and ornamenting walls of houses, furniture, &c. Of the utensils, brushes and
pencils of all sizes are requisite: the brushes ought to be straight, round and smooth; they
should before using be washed some time in warm water, that the wood of the handle may swell
and retain the hairs, which would otherwise be apt to fall off" and adhere to the work. The
brushes are commonly made of boar's bristles, or of a mixture of bristles and hair ; the pencils
are made of badger's hair or other fixed hair in quills of different sizes. The vessels used to
hold the various paints should all be well varnished, to prevent their drying quickly. When the
colours are ground in water they should be diluted in size made from parchment; and when
diluted with spirits of wine no more must be used than what will be necessary for the immediate
occasion, as colours prepared in this way dry rapidly. Colours ground in oil are also diluted
with pure oil, or oil mixed with essence of turpentine, or even with pure turpentine; which makes
them easy to work; but when varnish is added only what is requisite for the moment should be
prepared, as it must be immediately applied. The addition of varnish gives the colours great
brilliancy and dries speedily, but more art is necessary in using them. This part of painting
is divided into water and oil work, with or without the admixture of any varnish..
PAINTING