Selênio em Mumford (1934)

Unlike coal in long distance transportation, or like steam in local distribution, electricity is much easier to transmit without heavy losses of energy and higher costs. Wires carrying high tension alternating currents can cut across mountains which no road vehicle can pass over; and once an electric power utility is established the rate of deterioriation is slow. Moreover, electricity is readily convertible into various forms: the motor, to do mechanical work, the electric lamp, to light, the electric radiator, to heat, the x-ray tube and the ultra-violet light, to penetrate and explore, and the selenium cell, to effect automatic control. (Mumford 1934:223)

MUMFORD, Lewis. 1934. Technique and civilization. New York: Harcourt, Brace and Company.