Industry
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At the Idaho-Maryland Gold Mine in Grass Valley, an experimental vertical shaft five feet in diameter was drilled to a depth of 1125 feet through serpentine and gabbro using machinery invented by J.B. Newsom. The greatest drilled footage was 21 feet in three days, and the core weighed 11 tons. Kenneth E. Baker donated it to Nevada City.
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Nevada City, California · United States
