A LATHE.--The important things about a lathe are the spindle
bearings and the ways for the tool-holder. The least play in either will
ruin any work. Every other part may be defective, but with solidly
built bearing-posts and bearings, your lathe will be effective.

For this reason it will not pay to get a cheap tool. Better get a small,
6-inch approved tool of this kind, than a larger cheap article. It may
pay with other tools, but with a lathe never.

Never do grinding on a lathe. The fine emery, or grinding material, is
sure to reach the bearings; it matters not what care is exercised. There
is only one remedy for this--overhauling.

[Illustration: _Fig. 10.--Combination Square._]

COMBINATION SQUARE.--A tool of this kind is most essential, however
small. It can be used as a try-square, and has this advantage, that the
head can be made to slide along the rule and be clamped at any point. It
has a beveling and a leveling device, as well.

[Illustration: _Fig. 11.--Uses of the Combination Square._]

The combination square provides a means for doing a great variety of
work, as it combines the qualities of a rule, square, miter, depth gage,
height gage, level and center head.

[Illustration: _Fig. 12.--A Quick Adjusting Micrometer._]

The full page illustration (Fig. 11) shows some of the uses and the
particular manner of holding the tool.

MICROMETERS.--Tools of this description are made which will accurately
measure work in dimensions of ten-thousandths of an inch up to an inch.

The illustration (Fig. 12) shows an approved tool, and this is so
constructed that it can instantly be changed and set by merely pressing
the end of the plunger as shown.

[Illustration: _Fig. 13.--A Universal Bevel Protractor._]

PROTRACTORS.--As all angles are not obtainable by the square or bevel, a
protractor is a most desirable addition to the stock of tools. As one
side of the tool is flat it is convenient for laying on the paper when
drafting, as well as for use on the work.

The protractor has a graduated disk, and is adjustable so it can be
disposed at any angle.

[Illustration: _Fig. 14.--Universal Bevel Protractor, showing its
uses._]

All special tools of this kind are serviceable, and the boy should
understand their uses, even though he is not able for the time being to
acquire them. To learn how they are applied in daily use is an education
in itself.

UTILIZING BEVEL PROTRACTOR.--Examine the full-page illustrat