Chicago : [Popular Engineering Pub. Co.] · leaf 111
entirely satisfactory man- MOTOR DRIVEN ERASER ner. FOR DRAUGHTSMEN. The switch blades which open or A new application of the electric mo- close the circuit, thus turning off or on tor is for the operation of an eraser. The the power, are placed in large iron device is adapted for use in draughting… … It may seem strange that oil, being of erasures, owing to the high speed at an inflammable nature, is used in the which the eraser wheel revolves. tanks instead of water. But water is The eraser wheel is driven with a flex- a conductor of electricity and the fluid ible shaft by a small Westinghouse…
Electricity
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