Rocker or Cradle
A rocker was simply a rectangular wooden box, set at a downward angle and mounted on a rocking mechanism, usually like the rockers on a rocking chair. At the top was a sieve, and at the bottom was a series of cleats, or “riffles.” The dirt and rock was dumped into the top, followed by a bucket of water. The cradle was rocked by hand to agitate the mixture. The big rocks were caught in the sieve, the waste exited the lower end with the water, and the heavy gold fell to the bottom of the box and was caught on the riffles.
The rocker had advantages and disadvantages. The advantages were that the rocker was easily transportable; it did not require a constant source of water; and, most importantly, a miner could process more dirt and rock than with a gold pan. The primary disadvantage was that the rocker had difficulty in trapping the smallest particles of gold, commonly known as “flour.”
Some miners added small amounts of Mercury to the bottom of the rocker. Due to its chemical composition, Mercury has a facility to trap fine gold. Periodically, the miners would remove the Mercury and heat it; as the mercury vaporized, it would leave free gold as a residue.
The rocker had advantages and disadvantages. The advantages were that the rocker was easily transportable; it did not require a constant source of water; and, most importantly, a miner could process more dirt and rock than with a gold pan. The primary disadvantage was that the rocker had difficulty in trapping the smallest particles of gold, commonly known as “flour.”
Some miners added small amounts of Mercury to the bottom of the rocker. Due to its chemical composition, Mercury has a facility to trap fine gold. Periodically, the miners would remove the Mercury and heat it; as the mercury vaporized, it would leave free gold as a residue.
