Nicomedes Conchoid is described in Eutocius' commentaries of Archimedes' book on Spheres and Cylinders. Archimedes glibly describes finding two mean proportionals
(equivalent to extracting a cube root). Eutocius describes a dozen more or less slippery ways of doing this. One involves a drawing apparatus invented by Nicomedes, on which this clock is based. Drag the red point to vary the curve.