matter now to find 10 degrees or 25 degrees, or any
intermediate line.

WHAT DEGREES ARE CALCULATED FROM.--The question that now arises is what
line one may use from which to calculate degrees, or at what point in
the circle zero is placed. Degrees may be calculated either from the
horizontal or from the vertical line. Examine Fig. 53. The working
margin indicated by the cross mark is your base line, and in specifying
an angle you calculate it from the work edge. Thus, the line A indicates
an angle of 30 degrees. The dotted line is 45 degrees.

[Illustration: _Fig. 52._]

[Illustration: _Fig. 53._]

[Illustration: _Fig. 54._]

THE DIVIDERS.--The dividers are used not only for scribing circles, but
also for stepping and dividing spaces equally. There is a knack in the
use of the dividers, where accuracy is wanted, and where the surface is
of wood. Unless the utmost care is observed, the spaces will be unequal,
for the reason that the point of the dividers will sink more deeply into
the wood at some places than at others, due to the uneven texture of the
wood grain. It will be better to make a line lengthwise, and a cross
line (A) for starting (see Fig. 54). You may then insert one point of
the dividers at the initial mark (B), and describe a small arc (C). Then
move the dividers over to the intersection of the arc (C) on the line,
and make the next mark, and so on.

Some useful hints along this same line will be found under the chapter
on Drawing, which should be carefully studied.

CHAPTER VII

HOW THE DIFFERENT STRUCTURAL PARTS ARE DESIGNATED

THE RIGHT NAME FOR EVERYTHING.--Always make it a point to apply the
right term to each article or portion of a structure. Your explanation,
to those who do know the proper technical terms, will render much easier
a thorough understanding; and to those who do not know, your language
will be in the nature of an education.

PROPER DESIGNATIONS.--Every part in mechanism, every point, curve and
angle has its peculiar designation. A knowledge of terms is an
indication of thoroughness in education, and, as heretofore stated,
becomes really the basis of art, as well as of the sciences. When you
wish to impart information to another you must do it in terms understood
by both.

Furthermore, and for this very reason, you should study to find out how
to explain or to define the terms. You may have a mental picture of the
structure in your mind, but when asked to explai