Fig. 2321.
[Fig. 2320] represents an example in which, the form being a curve, it would be best to have the template touch more than two teeth, as shown in the cut. By letting the side a, [Fig. 2321], of the template t terminate at the centre line of the two curves, and the end b terminate at the top of a curve, turning the template around would cause end a to envelop side c of the middle curve, thus increasing the scope of the template. Suppose, however, that the base curve d required to be true with the teeth, then a second template t′ must be used, its ends at e and f measuring an equal length or height, so that when they are placed even with the ends of the work, the distances g h being equal, the corrugations will be true to the curve d d. Now let it be supposed that, instead of making a template to test a piece of work such as in [Fig. 2321], it is required to make a template for use in making another piece of work that is to fit to piece w, then template t in [Fig. 2321] will not answer, because it is a female template, whereas a male one is required, so that the edge of the template may coincide with that of the work. But we may convert t, [Fig. 2321], into a [male template] by simply cutting off the edge a as far as the line j, and causing its right-hand edge to coincide with the edge of the work so that the latter, after being fitted to the template, may be turned upside down and fit upon the piece of work.
Fig. 2322.
Fig. 2323.
