millrind

300px|thumb|A bedstone and the rind A millrind or simply rind is an iron support, usually four-armed or cross-shaped, for the upper ("runner") stone in a pair of millstones.

The rind is affixed to the top of the square-section main shaft or spindle and supports the entire weight of the runner stone, which can be as much as several tons. The face of a runner stone usually has a carved depression, called the "Spanish cross", to accommodate the millrind. The rind is necessary because the grain is fed through the runner stone's central hole, so the spindle cannot be inserted through it like a cartwheel on an axle. ==Mechanism== A later refinement, replacing the cross, was to mount a mace onto the spindle, which fitted into a gimbal let into the runner stone. The device allowed the runner stone to move in two planes and thus follow the nether (stationary) stone more closely, but great care had to be taken to ensure that its weight was properly balanced. The separation of the nether stone from the runner, controlling the fineness of the grind, was adjusted by the tenter mechanism: a screw jack to raise or lower the bearing carrying the base of spindle.