The jigger.  Promising fines or gravel was shovelled into the box, which has a bottom with small holes, and dunked up and down in the tub of water.  The much denser MIO ended up as a layer at the bottom which could be taken out for finish processing. Towards the end of the mine's life the jigger was used to rework material from the dumps.

Californian stamps, powered from the Turgo wheel turbine.  Probably the only stamps anywhere still regularly working as originally installed.