centers penetrating the stock at the proper point. The stock is then
placed in the lathe, using two corresponding off-center points as
centers.

With the lathe running at third speed turn down the stock to the
horizontal line forming the ridge of the oval, excepting for a distance
of about 1-1/4" at the ends. The stock at the ends is necessary for the
off-centering and, if cut away, will spoil the centering for the other
side, especially at the live center end. The stock is then changed to
the other off-center points and the second side is cut down to the line.

All measurements are then laid out and the design is cut, changing the
stock in the lathe when necessary. Care should be taken that the sharp
ridge left on the work forms a straight line the full length of the
stock. After the design has been finished, the stock is centered on the
true center and a very thin cut is taken the full length of the object
to remove the sharp corners. The model is then sandpapered while the
lathe is running very slowly.

CHAPTER VII

DUPLICATE TURNING

Under the head of duplicate turning have been classified only such
models as clearly indicate the necessity of making two or more articles
to complete the model or set of articles desired. But it is not intended
to convey the idea that other models may not be made in duplicate as in
many cases it is very desirable and even preferable that they should be
made that way. Whatever the problem may be the suggestions offered at
this point may be applied effectively.

Whenever two or more models are to be made identically alike there are
always two possibilities of inaccuracies that will render the work
dissimilar: First, inaccurate measuring both for length and points of
new diameters and also on the new diameters themselves; second, a
variation in the curved surfaces either on long convex or concave cuts.

The first difficulty can be overcome to a great extent by the use of a
measuring stick. This stick should be made of any soft wood. It should
be straight on one edge and about the thickness of an ordinary rule. On
the straight edge lay off very carefully measurements for length,
shoulders, beads, concaves and all points where calipering for new
diameters will be necessary. Insert at each point measured a small brad
which has been sharpened at both ends, leaving the end protrude about
1/8". Care should be taken that all brads protrude the same distance.

After the stock has