“We had to turn out at six in the morning and keep at it till dark. This mill was a six-stamp affair, driven by steam. Six tall, upright rods of iron, as large as a man’s ankle, and heavily shod with a mass of iron and steel at their lower ends, were framed together like a gate, and these rose and fell, one after the other, in a ponderous dance, in an iron box called a “battery.” Each of these rods or stamps weighed six hundred pounds. One of us stood by the battery all day long, breaking up masses of silver-bearing rock with a sledge and shoveling it into the battery. The ceaseless dance of the stamps pulverized the rock to powder, and a stream of water that trickled into the battery turned it to a creamy paste. The minutest particles were driven through a fine wire screen which fitted close around the battery, and were washed into great tubs warmed by super-heated steam—amalgamating pans, they are called. The mass of pulp in the pans was kept constantly stirred up by revolving “mullers.” A quantity of quicksilver was kept always in the battery, and this seized some of the liberated gold and silver particles and held on to them; quicksilver was shaken in a fine shower into the pans, also, about every half hour, through a buckskin sack. Quantities of coarse salt and sulphate of copper were added, from time to time to assist the amalgamation by destroying base metals which coated the gold and silver and would not let it unite with the quicksilver.” - Quote from Roughing It by Mark Twain.
