flint-mill

from The Century Dictionary.

• noun In pottery-manuf., a mill in which burned and crushed flints are ground to powder for mixing with clay to form slip for porcelain. The mill has a pan with a bottom of quartz or feldspar blocks, and runners of silicious stone.
• noun In mining, an old safety device for producing light, consisting of a wheel of which the periphery was studded with flints, which, when the wheel revolved, struck against a steel and emitted a quick succession of sparks. Such sparks do not ignite fire-damp.