pin-mill

Century Dictionary and Cyclopedia

1. n. A kind of hide-mill for softening skins after they have been soaked in a weak solution of sulphuric acid, rinsed with clean water, and again steeped in a solution of sal-soda and soap, which neutralizes any traces of acid remaining after the rinsing process. It consists of a large drum, with pins projecting from the interior surface, in which the skins are placed loosely, the drum revolving till they are sufficiently pliable for future operations.