on, Nos. 1 and
2, p. 163[f091a]).

[Illustration (f091a): (1) and (2) Movement in a Procession]

The same with masses: you cannot put a number of forms together without
some sort of relation, either of general character and contour or some
uniting line. We may learn this principle from nature also. Look at a
heap of broken stones and debris, which in detail may contain all sorts
of varieties of form, as we find them tumbled down a steep place, as the
rocky bed of a mountain stream, a heap of boulders upon a hillside, or
the debris from a quarry or mine; in each case the law of gravity and
the persistence of force working together arrange the diverse forms in
masses controlled by the lines, which express the direction and degree
of descent, and the pressure of force. The same thing may be seen on any
hilly ground after heavy rain; the scattered pebbles are arranged in
related groups, combined and composed by the flow of miniature streams,
which channel the face of the ground and form hollows for their
reception (see Nos. 3 and 4, p. 163[f091b]). The force of the tides and
currents upon the sea-shore illustrates the same principle and affords
us magnificent lessons in composition, not only in the delicate lines
taken by the sculptured sand, but in the harmonious grouping of masses
of shingle and shells, weeds and drift, arranged by the movement of the
waves.

[Illustration (f091b): (3) Lines Left by a Watercourse, (4) Lines
Governing Fallen Debris from a Quarry.]

[Principles of Harmonious Composition]

So that we may see that the principles of harmonious composition are not
the outcome of merely capricious fancy or pedantic rule, but are
illustrated throughout the visible world by the laws and forces of the
material universe. It is for the artist to observe and apply them in his
own work of re-creation.

CHAPTER VII

Of the Relief of Form--Three Methods--Contrast--Light and Shade,
and Modelling--The Use of Contrast and Planes in Pattern
Designing--Decorative Relief--Simple Linear Contrast--Relief by
Linear Shading--Different Emphasis in relieving Form by Shading
Lines--Relief by means of Light and Shade alone without
Outline--Photographic Projection--Relief by different Planes and
Contrasts of Concave and Convex Surfaces in Architectural
Mouldings--Modelled Relief--Decorative Use of Light and Shade,
and d