Giant Drill Core

Photo Description

From sign next to core:

Shaft Drill Core
1935-36

Experimental vertical shaft 5 ft in diameter to 1125 ft depth through serpentine and gabbro at Idaho-Maryland Gold Mine, Grass Valley. Machinery invented by J.B. newsom. Greatest drilled footage 21 ft in three days. Core weight 11 tones. Donated to Nevada City by Kenneth E Baker.

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