s of the sketches. These are problems which have been
worked out, and to copy them freehand makes the work to be done over
again on a larger scale on the canvas of the picture. This would not
only take too much time, but the same result might not follow. For
this purpose a more mechanical process is commonly made use of, which
combines the qualities of exactness with a certain freedom of hand,
without which the work would be too rigid and hard.

="Squaring up."=--This process is called "squaring-up," and consists
of making a network of squares which cut up the study, and map out its
lines and proportions, and make it possible to be sure that any part
of the original will come in the same relative place in the copy no
matter what the size may be, and at the same time leaves the actual
laying out of the thing to freehand drawing.

The process is a very simple one. You mark off a number of points
horizontally and vertically on the study. Make as many as you think
best--if there are too few, you will have too much of the study in one
part; if too many, it makes you more trouble. It is not necessary that
there be as many points one way as the other; make the number to suit
the lines of the study.

Draw straight lines across the study from each of the points, keeping
them carefully parallel, and seeing to it that the horizontal lines
cross the vertical ones exactly at right angles. These lines cut the
study into right-angled parallelograms, which may be squares or not
according as the vertical lines are the same distance from each other
that the horizontal ones are, or not.

Number the spaces between the lines at the top, 1, 2, 3, etc., and at
one side the same.

Now if you square off a part of your canvas with the same number of
spaces at the top and the same number at the side as you have done
with the study, and keep the relation of the spaces the same, you can
make it as large or as small as you please, and you can draw the
outlines within those squares as they fall in the study, and they will
be the same in proportion without your having the trouble of working
to scale. The squares furnish the scale for you, and the proportion is
not of the study to the picture, but as the vertical spaces are to the
horizontal, in both the study and the picture.

By numbering the squares on the canvas to correspond with those on the
study, and noticing in which square, and in what part of it, any line
or part of a line comes, you