Ovals are generally turned by causing the work to move in and under
guidance of an "oval chuck".
[Illustration: FIG. 238.]
There seems no reason why the same result should not be arrived at by
communicating a movement to the rest supporting the cutting tool in
the following manner:--Let A, A, be lathe bearers, B, pulley, C, screw
of mandrel, D, template fixed thereon, E, friction wheel on the end of
bar F, G rest (a board of any convenient width) moving on pivots at
H. The friction roller, E, is to be kept in contact with the template
by the cord running over the pulley T, stretched by the weight L. The
rest will thus oscillate under the guidance of the template, which may
be either oval or rose engine pattern, and the cutting tool form the
pattern of the template used. There might be other modes of causing
the rest to oscillate on the same principle. The lathe would require a
slow motion, the same as with an oscillating mandrel.