72. We have Balance in a line when one half of it is the single or
double inversion of the other half; that is, when there is an equal
opposition and consequent equilibrium of attractions in the line. When
the axis of the inversion is vertical the balance is symmetrical.
[Illustration: Fig. 83]
There is Balance in this line because half of it is the single
inversion of the other half. The balance is symmetrical because the
axis is vertical. The balance, although symmetrical, is not likely
to be appreciated, however, because the eye is sure to move along a
line upon which there is no better reason for not moving than is found
in slight terminal contrasts. The eye is not held at the center when
there is nothing to hold the eye on the center. Mark the center in any
way and the eye will go to it at once. A mark or accent may be put at
the center, or accents, corresponding and equal, may be put at equal
distances from the center in opposite directions. The eye will then be
held at the center by the force of equal and opposite attractions.
[Illustration: Fig. 84]
In this case the eye is held at the balance-center of the line by a
change of character at that point.
[Illustration: Fig. 85]
In this case the changes of character are at equal distances, in
opposite directions, from the center. The center is marked by a break.
The axis being vertical, the balance is a symmetrical one.
73. The appreciation of Balance in a line depends very much upon the
attitude in which it is drawn.
[Illustration: Fig. 86]
In this case the balance in the line itself is just as good as it is
in Fig. 85; but the axis of the balance being diagonal, the balance
is less distinctly felt. The balance is unsatisfactory because the
attitude of the line is one which suggests a falling down to the left.
It is the instability of the line which is felt, more than the balance
in it.
[Illustration: Fig. 87]
In this case of double inversion, also, we have balance. The balance
is more distinctly felt than it was in Fig. 86. The attitude is one of
stability. This balance is neither axial nor symmetrical, but central.