DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.20658#0380
366
APPENDIX,
the turpentine on one side only. As soon as this part of the process is performed, a varnish is
applied, made of equal quantities of Canada balsam and spirits of turpentine, each of the best
and purest sorts. This varnish is laid on with a pencil ; but it must be done with great caution,
lest it should spread farther on the picture than is wished, and thereby render transparent
parts intended to remain dark and opaque : for it is the application of the varnish that produces
the transparency, as we may see every day in the effect of oils, butter, &c. on paper. If the
painting represent a fire-scene, when the varnish is quite dry, touch the flame with red lead and
gamboge, and deepen the smoke in such parts as are not enlightened by the fire, where also the
smoke itself should be gently tinged like the flame. The moon ought never to be tinged, but
left white : for although at rising and setting, both the moon and the sun appear of a reddish
hue, this is occasioned by their being seen through a thick stratum of vapour; and such is not
the time probably to be chosen, to represent the moon-light in a transparency.
It must be repeated that in this work an agreeable effect depends greatly on the subject in
which the action represented (and some action ought always to be shewn, where figures are in-
troduced) is judiciously combined with the scenery around, and the period of the night, w hen
it is supposed to have happened. For unless these circumstances are managed with probability,
however skilfully the mechanical part of the painting may be executed, tbe: piece will fail is
producing the effect intended, and only excite ridicule.
COLOURING OF MAPS.
Although it be true that the boundary between different countries,- unless it be a river, the
sea, or other well-defined natural separation, is most properly represented by ajint line, correctly
drawn according to the turns and windings of such boundary ; yet in practice, and in order to be
the more perceptible, so as to. arrest the eye, at some distance, it is usual to shade these bound-
aries, on each bide, with different colours, taking care that such colours on the same line, be so
different from one another as to leave no uncertainty of the separating line between them. The
colours generally used are Prussian blue, lake, sap-green, gamboge, distilled verdigris, &c.
which are ground up in water, and laid on neatly with a pencil, making the coloured band
exactly of the same hreadth all along; and taking particular care that one colour never cross
the bounding line, and encroach on the place of the colour of the opposite side. In some cases
the whole surface of a country, or of its several internal provinces and districts, is washed over
in a similar manner; but this practice is of no real service; and at the same time that it loads
the map it renders the names, &c. less distinct than when then the paper is left white. Sea
charts are generally shaded with Indian ink, on the margin of the water, deepest along the
shore, and fainter gradually farther out to sea. In some cases the whole surface of the sea is
shaded of a blackish hue, and the continents and islands are left entirely white.
As the paper on which maps and charts are engraved, is not always of a quality to bear
-washing with colours, dissolve some alum in warm water, and with a sponge moisten the paper
with the liquor while hot, which will prevent the colour from sinking*
This
APPENDIX,
the turpentine on one side only. As soon as this part of the process is performed, a varnish is
applied, made of equal quantities of Canada balsam and spirits of turpentine, each of the best
and purest sorts. This varnish is laid on with a pencil ; but it must be done with great caution,
lest it should spread farther on the picture than is wished, and thereby render transparent
parts intended to remain dark and opaque : for it is the application of the varnish that produces
the transparency, as we may see every day in the effect of oils, butter, &c. on paper. If the
painting represent a fire-scene, when the varnish is quite dry, touch the flame with red lead and
gamboge, and deepen the smoke in such parts as are not enlightened by the fire, where also the
smoke itself should be gently tinged like the flame. The moon ought never to be tinged, but
left white : for although at rising and setting, both the moon and the sun appear of a reddish
hue, this is occasioned by their being seen through a thick stratum of vapour; and such is not
the time probably to be chosen, to represent the moon-light in a transparency.
It must be repeated that in this work an agreeable effect depends greatly on the subject in
which the action represented (and some action ought always to be shewn, where figures are in-
troduced) is judiciously combined with the scenery around, and the period of the night, w hen
it is supposed to have happened. For unless these circumstances are managed with probability,
however skilfully the mechanical part of the painting may be executed, tbe: piece will fail is
producing the effect intended, and only excite ridicule.
COLOURING OF MAPS.
Although it be true that the boundary between different countries,- unless it be a river, the
sea, or other well-defined natural separation, is most properly represented by ajint line, correctly
drawn according to the turns and windings of such boundary ; yet in practice, and in order to be
the more perceptible, so as to. arrest the eye, at some distance, it is usual to shade these bound-
aries, on each bide, with different colours, taking care that such colours on the same line, be so
different from one another as to leave no uncertainty of the separating line between them. The
colours generally used are Prussian blue, lake, sap-green, gamboge, distilled verdigris, &c.
which are ground up in water, and laid on neatly with a pencil, making the coloured band
exactly of the same hreadth all along; and taking particular care that one colour never cross
the bounding line, and encroach on the place of the colour of the opposite side. In some cases
the whole surface of a country, or of its several internal provinces and districts, is washed over
in a similar manner; but this practice is of no real service; and at the same time that it loads
the map it renders the names, &c. less distinct than when then the paper is left white. Sea
charts are generally shaded with Indian ink, on the margin of the water, deepest along the
shore, and fainter gradually farther out to sea. In some cases the whole surface of the sea is
shaded of a blackish hue, and the continents and islands are left entirely white.
As the paper on which maps and charts are engraved, is not always of a quality to bear
-washing with colours, dissolve some alum in warm water, and with a sponge moisten the paper
with the liquor while hot, which will prevent the colour from sinking*
This