The world needs a new source of energy, an unspillable source.

Tightening a nut on a guide vane operating seromotor in TVA’s hydroelectric plant, Watts Bar Dam, Tennessee. Located 530 miles above the mouth of the Tennessee River, the dam has an authorized power installation of 90,000 kw., which can be increased to a

HYDROELECTRIC

Image taken on 1940-01-01 00:00:00 by The Library of Congress.