We have all chucked up a turning square of one kind or another and, with the set of tools common to most, roughed-out, parted-in, and gouged here, skewed there, and ended up with a potpourri of bumps and hollows that somehow pleased our senses. Lathe-hands over the centuries have been doing exactly that and, not surprisingly, have just about exhausted the number of different shapes that can be generated on a cylindrical surface.
In fact, because that number is relatively small, a system of naming evolved, and the art of turning became a matter of juxtaposing the shapes in ways that appealed to the eye while satisfying function in the final construction.
The figure on the following page includes most of the shapes you will be able to contrive, and the name ascribed to each. Your job is to pick a few of them, put them together in pleasing sizes and sequences, and come up with a work of art, or at least a leg, candlestick, or lamp. Of course the figure shows far too many individual features to be good design.
Only a few are included in most classical pieces. Assuming that the piece shown will be used in a horizontal position, let us start with
the bottom or the base and work to the top. The turners of old probably plunged in with a parting tool to mark the location of each feature first, then went back and finished between the sizing cuts.
The first section is called a plinth (1) because it is at the base and is straight-sided. Next is a torus (2), and it is a large, semi-circular shape. Above the torus is a scotia (3), from the Greek word for “shade,” so called because it is a sunk-in ovolo (compare 7). And next, perhaps the most classical of all basic forms, is the ogee (4). It is just an S shape, but it can be stretched or compressed and is usually asymmetrical in one direction or the other. Note the difference between shapes (4) and (13). With the large bulge below, it is ogee, cyma recta, and with the bulge above, it is ogee, cyma reversa.
An astragal (5) is semi-circular form that extends above the surface of the piece but is much smaller than a torus. A straight section occurring somewhere in an upper area can simply be called a neck (6). Above the neck is a protruding segment of an ellipse, an ovolo (7). Above this is a quarter-hollow (8), topped by a quarter-round (9), and then, abruptly, a ball (10), which could be elongated into an ellipse. The abrupt transition, itself called a quirk, is the only such transition on the spindle; all other shapes are separated by straight sections (called fillets), which are parallel to the axis. The flat that ends the quarter round perpendicular to the axis is just that, a flat.
Cut into the maximum diameter of the ball (or ellipse) is a semicircular bead (11). The difference between a bead and an astragal is now obvious—the bead is cut into a surface and an astragal protrudes above it. Topping the ball, a series of three fillets (12), stair-stepped in reverse, effects the transition to the ogee, cyma reversa (13). Next comes a semi-circular hollow called a cavetto (14).
You might want to call this a cove, which is a loose name for any hollow. If the hollow is semi-circular, it is a cavetto; if it is elliptical, it is a scotia.
Next is a uniform series of three beads (it could be more than three), called a reed (15). The spindle is topped by another vertical, straightsided section similar to the plinth at the bottom. However, because of its position at the top, it is called an abacus (16).
There is just about only one other turned form I can think of—a V, either negative or positive. I have
researched a goodly number of classical turned pieces, and the V is notably absent. Beyond the harsh feel and poor wearing characteristics of the positive V, I do not know why this shape has no classical favor.
So, as woodturners—beginner, intermediate, or expert—I’m quite sure these old names are new to most of you. I feel it worthwhile to resurrect this ancient lore of naming. Happy turning, now that you can name what you are doing to that billet of wood!