Howard, Frank: The sketcher's manual: or, the whole art of picture making reduced to the simplest principles by which amateurs may instruct themselves without the aid of a master (London, 1841)

8 BREADTH.

dark,) so as to form what is technically termed
a mass of light (or shadow) in which, as ahove
stated, there should be an apex or focus of
brilliancy, (or a heart of depth.)

By this graduation the lights (or shadows)
are incorporated with the shadows (or lights),
and with each other, and diffused throughout
the whole breadth of the subject, and thereby
produce the unity of a picture.

Breadth is the great mean of the art for
the production of unity.

Note.—It may perhaps serve to make the term Breadth more
intelligible to the unpractised reader, to say, that in general, a
large luminary, the sun, affords breadth of light; and a small
luminary, a candle or small aperture, by reason of its deficiency
of light, affords breadth of shadow.