Images of Modernity

Mary Ellen Bowden and Erin McLeary

Photograph of female workers manufacturing transistors in Allentown, Pennsylvania, ca. 1950s. AGERE Systems Collection. Courtesy of the National Canal Museum, Easton, Pennsylvania.

Developed in the late 19th century, vacuum tubes, X-ray tubes, and lightbulbs offered scientists, physicians, and consumers a new level of control over space and time. The tiny transistor, developed in the late 1940s as a rugged alternative to the delicate vacuum tube, shrank space even more dramatically. Researchers at Bell Labs in the late 1940s working on a solid-state amplifier were exultant when they succeeded in creating one from a sliver of the semiconductor germanium and some wires. This tiny device, which they dubbed the “transistor,” performed many of the same switching and amplifying functions as the vacuum tube, but at a greatly reduced size. Although early transistors were quirky and fickle handmade devices, within a few years improved transistors began to replace vacuum tubes in such applications as radios, hearing aids, and telephone circuits.