Cox, David: A series of progressive lessons intended to elucidate the art of painting: with introductory illustrations on perspective and drawing with pencil (London, 1845)

18

the outline of the respective parts, which must be particularly attended to.
Then take the strong tint, No. 3; put in the masses of shadow requiring
force, retouching until the effect he obtained. In the foregoing process, it is
intended for the edge of each tint to be distinguished; if it should seem too
sharp in any particular part, it may be blended with a tint much lighter than
No. 1, or with a pencil dipped in clean water. A drawing can be made with
the use of one tint only; but by repeated tedious washings, a spiritless effect
will be produced; freedom and spirit are sacrificed in the endeavour to give
too great a degree of finish. Keep the washes of sepia as broad as the nature
of the subjects will admit. Enlarging now and then a subject, four or six
times the size of the original, gives scope for boldness and freedom of hand.
Reversing the lights and shadows, making the sky dark and the building light,
in the view of Beaucliff Abbey; such practice is of considerable advantage
to the learner; it induces the mind to exert itself, and excites a desire to
sketch from nature.