side not only has variety in itself, but there is
usually variety of opposition. Supposing there is a convex curve on the
one side, you will often have a concave form on the other. Always look
out for this in drawing limbs, and it will often improve a poorly drawn
part if more of this variation on symmetry is discovered.

The whole body, you may say, is symmetrical, but even here natural
conditions make for variety. The body is seldom, except in soldiering,
held in a symmetrical position. The slightest action produces the
variety we are speaking about. The accompanying sketches will indicate
what is meant.

[Illustration: Diagram IX.

ILLUSTRATING VARIETY IN SYMMETRY

Note how the hollows marked A are opposed by the fullnesses marked B.]

Of course the student, if he has any natural ability, instinctively
looks out for all these variations that give the play of life to his
drawing. It is not for him in the full vigour of inspiration that books
such as this are written. But there may come a time when things "won't
come," and it is then that it is useful to know where to look for
possible weak spots in your work.

[Sidenote: Variety of Thickness and Accent.]

A line of equal thickness is a very dead and inexpressive thing compared
with one varied and stressed at certain points. If you observe any of
the boundaries in nature we use a line to express, you will notice some
points are accentuated, attract the attention, more than others. The
only means you have to express this in a line drawing is by darkening
and sharpening the line. At other points, where the contour is almost
lost, the line can be soft and blurred.

It is impossible to write of the infinite qualities of variety that a
fine draughtsman will get into his line work; they must be studied first
hand. But on this play of thickness and quality of line much of the
vitality of your drawing will depend.

XII

RHYTHM: UNITY OF LINE

Unity of line is a bigger quality than variety, and as it requires a
larger mental grasp, is more rarely met with. The bigger things in
drawing and design come under its consideration, including, as it does,
the relation of the parts to the whole. Its proper consideration would
take us into the whole field of Composition, a subject needing far more
consideration than it can be given in this book.

In almost all compositions a rhythmic flow of lines can be traced. Not
necessarily a flow of actual lines (although the