CIRCULAR REST.
The rest we have already described, called the Parallel Rest, works, as its name sufficiently expresses, in a straight line; it is therefore useless for ornamenting spherical objects, and the circular rest has lately been invented to supply this deficiency. It is a most ingenious contrivance, and perfectly fulfils the purpose for which it was invented.
Plate 8.
The bed, A A, is the same as in the parallel rest, and screws in the same way to the bed of the lathe. B is a brass socket and pillar, which support the bed C, in which the tool box slides; they are formed in the same piece with the lower bed, L L, and firmly fixed into the lower part, which is grooved, by four brass-headed screws, N N. The grooves enable the whole socket and tool box to slide backwards and forwards on the bed of steel, D D, and by means of the screw which passes through it the workman regulates the advance or retreat of the rest to or from the work in a straight line, while the lower part remains stationary. The small wheel, E, is graduated, and turned by a key, to enable the turner to count the distance. F is a steel spindle, which works in two brass collars, G G; about half-way down. The spindle is formed into a screw, O, which turns upon the brass wheel, H, and by moving the nut, J, moves the whole rest in a circular direction, in the same way that the screw in the steel bed, D D, impels it in a straight line: by this ingenious contrivance all objects that are round or spherical can be ornamented: such as balls, the globular sides of vases, or small baskets, in every variety of pattern. The learner will easily discover the proper method of using this rest, which is very simple in its mechanism and use. The nut, K, is for setting the tool slider at different angles, the same as in the parallel or sliding rest; the tools to be employed are those of the above-mentioned rest.