the pieces are to be made, the greater part
of blacksmith work is made of wrought iron, and it is, therefore,
unnecessary to write "wrought iron" beneath each piece. When the pieces
are to be of steel, however, it should be marked on the drawing and
beneath the piece. In special cases, as where the greater part of the
work of the shop is of steel, the rule may, of course, be reversed, and
the parts made of iron may be the ones marked, whereas when parts are
sometimes of iron, and at others of steel, each piece should be marked.

As a general rule the blacksmith knows, from the custom of the shop or
the nature of the work, what the quality or kind of iron is to be, and
it is, therefore, only in exceptional cases that they need to be
mentioned on the drawing. Thus in a carriage manufactory, Norway or
Swede iron will be found, as well as the better grades of refined iron,
but the blacksmith will know what iron to use, for certain parts, or the
shop may be so regulated that the selection of the iron is not left to
him. In marking the number of pieces required, it is better to use the
word "thus" than the words "of this," or "off this," because it is
shorter and more correct, for the forging is not taken off the drawing,
nor is it of the same; the drawing gives the shape and the size, and the
word "thus" conveys that idea better than "of," "off," or "like this."

In shops where there are many of the same pieces forged, the blacksmith
is furnished with sheet-iron templates that he can lay directly upon the
forging and test its dimensions at once, which is an excellent plan in
large work. Such templates are, of course, made from the drawings, and
it becomes a question as to whether their dimensions should be the
forged or the finished ones. If they are the forged, they may cause
trouble, because a forging may have a scant place that it is difficult
for the blacksmith to bring up to the size of the template, and he is in
doubt whether there is enough metal in the scant place to allow the job
to clean up. It is better, therefore, to make them to finished sizes, so
that he can see at once if the work will clean up, notwithstanding the
scant place. This will lead to no errors in large work, because such
work is marked out by lines, and the scant part will therefore be
discovered by the machinist, who will line out the piece accordingly.

Figure 223 is a drawing of a locomotive frame, which the student may as
well draw three or fo