The Artist's Assistant, In the Study and Practice of Mechanical Sciences: Calculated for the Improvement of Genius. Illustrated with Copper-Plates (Birmingham, [ca. 1785])

136 THE ARTIST'S ASSISTANT.

Cinnabar and black is alfo a very ufeful compound,
from which feveral different teints fhould be made.

Pruffian blue and black is another gdoct compound,
and will be found of angular fervice in painting
draperies.

It is impofhble to lay down rules for forming
every teirit neceiTary in cOtnpofing a fet of crayons,
there being many accidental comoofitions, entirely
dependent on fancy and opinion. The ftudent fhould
make it a rule to five the leavings of his colours,
for of thefe he may form various teints, which will
occafionally be ufeful.

Of ROLLING the CRAYONS and
DISPOSING them for PAINTING.

'JpKE different compofitions of colours Email be
cut into a proper magnitude after thev are
prepared, in order to be rolled into paftils for the
convenience of ufmg them. Each crayon fhould be
formed in the left hand with the ball of the right,
firft formed cyllndrically, and then tapered at each
end. If the compohtion is too drv, dip the finger
in water; if too wet the compohtion muff be laid
upon the chalk again to abforb more of the moif-
ture. The crayons fhould be rolled as quick as pof-
fible ; and when finifhed, mull be laid upon the
chalk again, to abforb all remaining moifHire. Alter
the gradation of teints from one colour are formed,
the chalk and the grinding-flone fhould be well
fcraped and eleanfed with water before it is uied
for another colour,

When