the rubber, a figure will be cut the shape of the rosette, and of a size corresponding to the distance of the tool's point from the zero of the scale. These figures can be cut one inside the other at any intervals, by merely altering the distance of the tool's point from the

centre.

If the centre of the figure coincide with the lathecentre, the angular position of the figure may be altered at pleasure by shifting round the division-plate of the lathe and thus presenting a fresh place to the action of the cutter tool. If, however, the slide-rest be shifted and the tool applied, a rose figure will be cut at a distance from the lathe-centre depending upon the distance the slide-rest was moved, and by moving the division-plate of the lathe around so many divisions at a time, a series of these rose figures will be cut, eccentric to a common centre, precisely the same as the plain circles cut with the eccentric instrument.

If now it be desired to alter the angular position of the figures, with regard to their own centre, it is obvious this cannot be done by presenting a fresh place to the tool, but it must be done by presenting the tool to a fresh place. For this it is necessary to move round the rosette on the stem of the instrument, and to enable this to be done, the tangent screw at the back of the rosette is applied. By turning this screw the rosette is moved to a fresh position, so that upon putting the instrument in motion and applying it to the work, the same figure will be cut, but in a different angular position. By moving the tool along the eccentric frame past the centre to the side opposite the roller, and applying it in motion to the surface, a

different figure altogether will be produced. In the previous position a prominence in the rosette forced the slide so as to bring the tool farther from the centre of the figure; but in this position a prominence has the effect of bringing the tool nearer to the centre, and a figure is now cut exactly the reverse of the previous one. There is the same power of enlarging these figures or altering their position as in the other.

FIG. 198.

The lifting or stop-screw also gives the means of producing another sort of figure from any rosette. By moving the screw so as to partially raise the roller off the rosette, the full travel of the slide will be prevented, and a series of flat lines will be made at those points at which the roller is prevented touching the rosette.

Fig. 198 illustrates the uses of the rose-cutting instrument. The outside of the pattern is

formed by shifting the position of the rosette between every cut. The inside part is a series of concentric rosettes, to produce which the cutter was moved further from the zero point between every cut.

Besides the chucks and instruments described there are several others, but they are little used and are comparatively unimportant. Among these are the epicycloidal chuck, the straight-line chuck, the roseengine, &c.

The first is rather a complicated instrument for producing epicycloidal figures, most of which can be obtained by the other apparatus. It goes on to the

mandril end in the same manner as the others. The straight-line chuck is an instrument placed on the mandril end for getting right line motion-some varieties of this chuck are made to work with the continuous rotation of the lathe-spindle, others require the motion of the lathe to be alternate. The rose-engine is a lathe in which the rose figures already described are obtained by moving the work instead of moving the tool.

This is done by making the whole of the latheheadstock rock to and fro under the guidance of rosettes placed on the lathe-spindle, and which in revolving rub against fixed points or rollers, and so give a rocking motion to the work. It is a clumsy and complicated piece of mechanism, expensive, and of comparatively little service.

The geometric chuck is the most complicated of all the ornamental turning chucks, but that is correspondingly useful. Almost the whole of the figures which can be produced by the chucks described, either alone or combined, can be obtained by the geometric chuck. I shall therefore reserve the description of it and its uses until after I have given a few explanations of the modes of combining the various chucks and instruments already described.

COMBINATIONS OF ORNAMENTAL APPARATUS.

Hitherto I have explained only the simple uses of the various chucks and instruments used by the ornamental turner; enough has been said, however, to convey a good impression of the uses of each; and the instruction given, if attended to, can scarcely fail

to enable the operator to be tolerably successful in his attempts at ornamental engraving.

The first great step to success is to understand thoroughly the simple uses of the instruments, and not attempt more complicated combinations of instruments until acquainted with their separate uses and capa

bilities. Without this knowledge their combined action would be conducted blindly, and appear to be dependent upon chance only for success.

I may mention that the figures given have been chosen as the ones best adapted to show the combined action of the instruments. These may be modified, and other patterns be obtained with but slight alteration, many of which will almost equal in beauty those ob

tained by the geometric chuck. It will not be necessary for me to explain every step and movement required to produce the patterns, as, after the instruction already given, the reader will have no difficulty in seeing for himself.

Fig. 199 was produced by a combination of the segment-wheel and eccentric chuck, with a fixed tool in the slide-rest.

Fig. 200 was produced by the eccentric cutter and eccentric chuck, the cutter being shifted by the screw of the slide-rest between every cut.

Fig. 201 was produced by the same instruments and in a similar manner.

The inside curved lines were made by the segmentwheel.

Fig. 202 was made by the eccentric cutter and eccentric chuck, the circles of the cross being spaced by the slide-rest screw, the circles forming the border by the division-plate of lathe.

Fig. 203 was produced by the eccentric cutter, which made the small circles. The ellipse shape can be obtained either from the ellipse-chuck, or by using the eccentric chuck, with the division-plate of the lathe.