etc.; and its form, size and shape may be varied according to the taste
of the individual. As in threads so in spiral work we have single and
double spirals, and their form and proportion depend upon their use and
application in furniture making. A variation of the spiral may be made
in several ways: First, by changing the number of turns of the spiral on
a straight shaft; second, by running a spiral on a tapered shaft; third,
by changing the shape or form of the spiral itself; and fourth, by
making more than one spiral on a shaft. It is uncommon to see ten or
twelve spirals running around a single shaft.

Some of the forms of the above types are fully taken up and explained in
the work that is to follow.


PLATES B-V--1-a, a´. SINGLE SPIRAL. STRAIGHT SHAFT

To work out a single spiral for a pedestal proceed as follows:

1. Turn a cylinder 2-1/4" in diameter. Make the ends slightly larger in
order that the design may be turned on each, after the spiral has been
worked out.

2. Lay off spaces 2-1/16" apart on the cylinder while the spindle is
turning in the lathe and divide each of these into four equal parts.
Each one of these large spaces represents one turn of the spiral. A good
proportion is slightly less than the diameter of the cylinder; thus the
diameter of the cylinder equals 2-1/4" and the width of the space
2-1/16".

3. On the cylinder parallel to the axis draw lines A-A B-B C-C D-D.