worried to distraction trying to paint the profile line from the face side, fearing to lose the drawing by going over the edge.  With the edge blurred out from the face side, it is easy to come with a brush full of the colour the background is immediately against the face (a different colour usually from what it is further away), and draw it with some decision and conviction, care being taken to note all the variations on the edge, where the sharpnesses come and where the edge is more lost, &c.

[Sidenote:  Variety in Symmetry.]

The contours of the limbs illustrate another form of line variety—­what may be called “Variety in Symmetry.”  While roughly speaking the limbs are symmetrical, each 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.