The shafts and bases of the Banner screens, figs. 668. 669 about fifteen to eighteen inches high, would be turned from three or four pieces, and those of the Candle shade, fig. 667, from two; the slender cross rods, attached by silk cords, and the shafts, would require similar precautions in turning and fitting them together, to those lately described.

The outlines of figs. 670 to 678, reduced from Etruscan Vases, are intended to illustrate the characteristics and to indicate a few of the numberless varieties of curvatures, resulting from combinations of portions of the oval line. In these as in all forms derived from this source, ornament is markedly subordinate, their excellence arising solely from the balance and quality of the outline; for which and other reasons already alluded to, more instructive examples of form for plain turning cannot be advanced.

Viewing these figures as sections, in some the oval giving the main outline is axial, more generally, as in fig. 673, it is removed, the vertical or long diameter of the oval being eccentric and placed at an angle to the axis of the work. In nearly all portions of the curved outline are returned, that is, are alternately concave and convex, ovals of differing curvature and magnitude being usually opposed, but the one line always gliding into the other as a smooth continuous curve. Further variety arises from the vertical height at which the main form may be truncated by the lip, neck or foot, the outlines of which portions are themselves also contained by oval curves. The three central vases in which the oval outlines are not axial, also differ from variety in the ovals employed, both from the relative proportions of the large and small ends of the curves, and from the straighter or more rounded curvature of their long sides; differences common to the egg and all natural oval forms. Apart from the aesthetic value of this last property, the exceeding variety that oval outlines will admit is particularly valuable in turning, meeting most accidents found in the material or arising from manipulation in the progress of the work; necessary departures from the predetermined form, so long as they harmonize with the character of the oval, always producing a true and agreeable contour.

Figs. 670 to 678, of small or moderate dimensions, may all be turned from single pieces of wood or ivory, frequently at a single chucking, the material mounted in metal plain chucks. With increased scale the support of the popit head is required; the material at first carried by the prong chuck, or fig. 286, and afterwards in a plain chuck, has its external and internal form turned true and roughly reduced somewhat to proportion, sufficiently to observe whether it will carry out the design. The hollow and the upper portion of the lip are then completed, and the work reversed and chucked by its aperture upon the fillet of a plain wood chuck, being adjusted to again run true before the popit head is brought up. All portions of the external form are then finished, the incised lines upon the body of the vase, the only approach to ornament, being finally cut in with a point tool. The vases are effective and serve many purposes when executed upon a still larger scale in hard or softwood, and the latter may be afterwards stained and polished. Of such magnitude they are constructed in several pieces, some joints occurring at the neck and foot, while others which have to be placed in the body of the vase, are concealed by incised lines, or some shallow moulding level with the outline.

Axial Or Simple Plain Turning Part 10 400367