This article looks at the history and present-day state of thermocouples used in the glass industry. The advent of thermocouple temperature measurement and ultimate control is relatively recent, steming from the 1830-era discoveries of Seebeck of the thermal electric effect and the 1890 era of LeChatelier, who demonstrated the practical use of platinum vs platinum 10% rhodium alloy thermocouples. Thermocouple use in the glass industry for actual process control is an even more recent achievement. In the 1950s, radiation pyrometers, based on thermal pile technology, were used extensively to monitor, if not control, breast wall, checker, batch, refiner and crown temperatures. Glass temperature was inferred by refractory temperature and the workability of the glass.