e justly much broken into
by truths of natural appearance. But an emotional significance depending
on some arrangement of abstract lines is to be found underlying the
expression in every good picture, carefully hidden as it is by all great
artists. And although some apology is perhaps necessary for the ugliness
of these diagrams, it is an ugliness that attends all anatomy drawings.
If the student will trace them and put his tracing over the
reproductions of the originals, they will help him to see on what things
in the arrangement the rhythmic force of the picture depends.

Other lines, as important as those selected, may have been overlooked,
but the ones chosen will suffice to show the general character of them
all.

* * * * *

There is one condition in a composition, that is laid down before you
begin, and that is the shape of your panel or canvas. This is usually a
rectangular form, and all the lines of your design will have to be
considered in relation to this shape. Vertical and horizontal lines
being parallel to the boundaries of rectangular pictures, are always
right and immediately set up a relationship, as we have seen.

The arresting power of the right angle exists at each corner of a
rectangular picture, where the vertical sides meet the horizontal base,
and this presents a difficulty, because you do not wish the spectator's
attention drawn to the corners, and this dramatic combination of lines
always attracts the eye. A favourite way of getting rid of this is to
fill them with some dark mass, or with lines swinging round and carrying
the eye past them, so that the attention is continually swung to the
centre of the picture. For lines have a power of directing the
attention, the eye instinctively running with them, and this power is of
the greatest service in directing the spectator to the principal
interest.

It is this trouble with the corners that makes the problem of filling a
square so exacting. In an ordinary rectangular panel you have a certain
amount of free space in the middle, and the difficulty of filling the
corners comfortably does not present itself until this space is arranged
for. But in a square, the moment you leave the centre you are in one or
other of the corners, and the filling of them governs the problem much
more than in the case of other shapes. It is a good exercise for
students to give themselves a square to fill, in order to understand
this dif