1) Pig in a sty 2) Pig in a sty, often 
The Wallower is a driven gear at the top of the Upright Shaft in Smock, Tower and some Post mills. It is driven by the Brake Wheel
• (n.) A lantern wheel; a trundle. • (n.) One who, or that which, wallows.
The Wallower is a small gear at the base of the upright shaft in a watermill, it is driven by the Pit Wheel.
Wal'low·er noun 1. One who, or that which, wallows. 2. (Machinery) A lantern wheel; a trundle. 
The Wallower is a driven gear at the top of the Upright Shaft in Smock, Tower and some Post mills. It is driven by the Brake WheelThe Wallower is a small gear at the base of the upright shaft in a watermill, it is driven by the Pit Wheel.