National Geographic : 1943 Jan
The National Geographic Magazine A Tiny Fever Thermometer Begins as a Big Gob of Glass First the operator works the hot glass with metal jacks to distribute the bubble which will become a bore only a fraction as thick as a human hair (upper left). A strip of opaque white glass is applied to be the background for the mercury column (upper right). The glass is reheated, rolled, and then placed in a V-shaped die at workman's right, where magnifying lens is formed (lower). First six pictures in series were taken at Corning Glass Works; the seventh at the Taylor Instrument Companies plant (pages 25, 26).