These lessons if carried out conscientiously will enable the operator to produce almost any form in so far as the manipulation of the clay is concerned but the work up to this point is drill only. It is not intended that the pieces should be preserved. The next point is to insist that the clay obey the potter in the shaping of a form.
A simple drawing of a jar should be made exact to the size proposed. Two or three pairs of calipers are provided and with them the diameter of each part of the drawing is taken. Of course a single pair could be made to serve, but it is very inconvenient to change measurements while working. A piece of wood also is cut to the height of the proposed piece. The throwing is begun as usual by making a cylinder. This should be higher than the drawing for the clay sinks in the shaping. First the bottom is pressed into the proper size (Lesson VI). Then the body is enlarged to the required measure and, lastly the diameter of the top is taken and the height brought to the determined point. If too high the superfluous clay may be cut off with a pointed knife, the edge being carefully rounded afterwards.
It is only by checking up one's work in some such way as this that real power can be acquired. The skilled worker can think in the clay and create forms at will upon the moving wheel, but for the beginner to attempt this is like an endeavor to paint pictures before one has learned to draw. Shape after shape should be designed, drawn to scale and thrown to measure; in fact, for elaborate pieces no other course is possible.
CHAPTER X
Turning
It is not possible to finish work to perfection in the operation of throwing. The clay is too soft to handle and for proper finishing the piece must be turned over to get at the bottom. An experienced thrower reduces the final work to a minimum and this, of course, is the ideal plan but even in factory practice every thrown piece is passed on to the turner so that the phrase "thrown and turned" is used as of a single operation, though it, in fact, expresses not only two processes but the work of two men.
The artist-potter must needs, therefore, learn to turn, though this process should not be worked to death as it is liable to be. Many persons in the pride of having produced some sort of a form on the wheel will leave it in the crudest possible condition and trust to the turning tool to remove defects. If the lessons on throwing have been conscientiously carried out, this error will not be committed.
A half dozen cylinders of convenient size should be thrown on separate bats and set aside in a cool place to harden. They must not be dried but should be in the condition known as "leather hard." If thrown one day they will be ready for turning the next morning. Pieces thus hardened are no longer flexible. They can be handled freely and the clay can be easily cut with a knife.
Fig. 19. Turning tools bent and sharpened.