Page "Placer mining" Paragraph 10

Miners working a sluice on Lucky Gulch, AlaskaThe same principle may be employed on a larger scale by constructing a short sluice box, with barriers along the bottom called riffles to trap the heavier gold particles as water washes them and the other material along the box.

This method better suits excavation with shovels or similar implements to feed ore into the device.

Sluice boxes can be as short as a few feet, or more than ten feet ( a common term for one that is over six feet +/- is a " Long Tom ").

Similar in principle to a sluice is a rocker, a cradle-like piece of equipment that could be rocked to sift sands through screens, which was introduced by Chinese miners in British Columbia and Australia, where the practice was referred to as " rocking the golden baby ".

Another Chinese technique was the use of blankets to filter sand and gravels, catching fine gold in the fabric's weave, then burning the blankets to smelt the gold.

Chinese were noted for the thoroughness of their placer extraction techniques, which included hand-washing of individual rocks as well as the complete displacement of streambeds and advanced flume and ditching techniques which became copied by other miners.