Electricity in modern mining installations -- an alternating current motor driving a mining pump underground.
Source: Steve Kirch, collector, and creator of a great website about SCIENTIFIC AMERICAN in the past
Restoration by: magscanner
Electricity in modern mining installations -- an alternating current motor driving a mining pump underground.
Source: Steve Kirch, collector, and creator of a great website about SCIENTIFIC AMERICAN in the past
Restoration by: magscanner