ght across the file, but at an angle to the
direction of the dart.

[Illustration: _Fig. 56. Correct File Movement_]

INJURING FILES.--Now the frequent practice is to use the file as shown
in Fig. 57, in which case it is moved across obliquely. The result is
that the angle of the file cut is so disposed that the teeth of the file
do not properly aid in the cutting, but in a measure retard the
operation.

File teeth are disposed at an angle for the purpose of giving them a
shearing cut, which is the case when the file moves across the work on a
line with its body.

To use a file as shown in Fig. 57 injures the file without giving it an
opportunity to cut as fast as it would when properly used.

[Illustration: _Fig. 57. Incorrect File Movement_]

DRAWING BACK THE FILE.--In drawing back a file it is always better to
allow it to drag over the work than to raise it up. It is frequently the
case that some of the material will lodge in the teeth, and the back
lash will serve to clear out the grooves.

This is particularly true in filing copper, aluminum, lead, and like
metals, but it is well to observe this in all cases.

CHAPTER V

HOW TO COMMENCE WORK

The question is often asked: Where and how shall the novice commence
work?

When the shop is equipped, or partially so, sufficient, at least, to
turn out simple jobs, the boy will find certain tools which are
strangers to him. He must become acquainted with them and not only learn
their uses, but how to use them to the best advantage.

FAMILIARITY WITH TOOLS.--Familiarity with the appearance of tools, and
seeing them in the hands of others will not be of any value. Nothing but
the immediate contact with the tool will teach how to use it.

FILE PRACTICE.--The file is a good tool to pick up first. Select a piece
of metal, six or eight inches long, and follow the instructions laid
down in the chapter relating to the use of the file.

Practice with several kinds and with different varieties of material
will soon give an inkling of the best kind to use with the metal you
have. Use the straight edge and the square while the filing process is
going on, and apply them frequently, to show you what speed you are
making and how nearly true you are surfacing up the piece.

USING THE DIVIDERS.--Then try your hand using the dividers, in
connection with a centering punch. As an example, take two pieces of
metal, each about a foot long, and set the dividers to make