Their extraordinary richness may be inferred from the fact that many claims were profitably worked in them by sinking shafts to a depth of 200 feet or more, and hoisting the dirt by a windlass.

它们非凡的丰富性可以从这样一个事实中推断出来：许多索赔都是通过将竖井下沉到 200 英尺或更深，并用卷扬机吊起泥土来获利的。