The material for the hardwood cone is first turned fairly cylindrical, nearly to the diameter of the base, and the end surfaced; the height of the intended cone is then marked off upon it, measured from the base, at the chuck end. Should the work be carried between centers or be of sufficient length to require the support of the popit head, the height is marked a little in excess to allow for the small reversed cone to receive the point of the latter, turned away in the course of the process, as explained for turning this solid in softwood.

The management of the tools differs so slightly from that for the cylinder, as to require but little notice. The work is first roughly reduced to the conical form by the gouge, held and used as upon the cylinder; the tee of the rest being from time to time placed parallel with the side of the work, as that gradually assumes the conical shape. In finishing, the tee is fixed parallel with the side of the cone. The work is turned smooth with the flat tool, first by separate cuts and then by continuous shavings, taken always in one direction from the base to the point, or downhill; when the tool, cutting obliquely across the ends of the fibres, leaves the surface smooth and finished.

The internal cone is first roughly hollowed in much the same manner as the cylinder; the separate cuts are then connected into one line, by the right side, point, bevil, or flat tools, according to the angle. In finishing, the correct angle is ascertained by the turning bevil fig. 376, placed across the base or mouth; the steel blade enters the cone, and a large portion of the side can be turned to be truly in contact with it. The part turned to the true angle, then serves to guide the straight edged tool in continuing the same line into the apex. A right side tool, the cutting edge so far ground away as to meet the back in a point, is used for the apex of acute internal cones; more obtuse, fig. 428, may be entirely finished with the bevil tool, and truncated cones with the flat tool, all the continuous shavings being removed from the bottom outwards.

Tapering forms of the character indicated by figs. 429. 430, their outlines produced by concave or convex curves, are frequently required in hardwood turning, and may be considered as allied to the cone. They are produced in a similar manner with the right side, point or round tools, smaller tools being employed upon the narrower portions of the hollow. The tools are nearly always used upon the armrest, the shavings after the first rough hollowing, being taken from the center towards the orifice.

Fig. 428. Fig. 429. Fig. 430.

Section IV External And Internal Cones 400302