hown in two
views in Figure 130, and the process for the pencil lines is as follows:

[Illustration: Fig. 130.]

With the bow-pencil set to half the required length and breadth of the
square the arcs 1, 2, 3 and 4, in Figure 131, are marked, and then the
lines 5 and 6, letting them run past the width of the arcs 3 and 4.
There is no need to pencil in lines 7 and 8, since they can be inked in
without pencilling, because it is known that they must meet the arcs 3
and 4 and terminate at the lines 5 and 6. The top and bottom lines of
the edge view are merely prolongations of lines 5 and 6; hence the lines
9 and 10 are drawn the requisite distance apart for the thickness and to
meet the top and bottom lines. The lines are then inked in, the pencil
lines rubbed out, and the drawing will appear as in Figure 130.

[Illustration: Fig. 131.]

[Illustration: Fig. 132.]

Suppose, however, that the piece has a step in it, as in Figure 132, and
the pencilling will be as in Figure 133. From the centre, the arcs 1, 2,
3 and 4 for the outer, and arcs 5, 6, 7 and 8 for the inner square are
marked; lines 9 and 10, and their prolongations, 11 and 12, for the
edge view, are then pencilled; lines 13 and 14, and their prolongations,
15 and 16, are then pencilled, and dots to show the locations for lines
21 and 22 maybe marked and the pencilling is complete. Lines 17, 18, 19,
20, 21, 22, and 23 may then be inked in, in the order named, and then
lines 9, 10, 11, 12, 13, 14, 15 and 16, when the inking in will be
complete.

[Illustration: Fig. 133.]

In inking in horizontal lines begin at the top and mark in each line as
the square comes to it; and in inking the vertical ones begin always at
the left hand line and mark the lines as they are come to, moving the
square or the triangle to the right, and great care should be taken not
to let the lines cross where they meet, as at the corners, since this
would greatly impair the appearance of the drawing.

These figures have been drawn without the aid of a centre line, because
from their shapes it was easy to dispense with it, but in most cases a
centre line is necessary; thus in Figure 134 we have a body having a
number of steps. The diameters of these steps are marked by arcs, as in
the previous examples, and their lengths may be marked by applying the
measuring rule direct to the drawing paper and making the necessary
pencil mark.

But it would be tedious to mark the successive steps tru