Mercury-in-glass thermometer Mercury-in-glass thermometer The mercury-in-glass or mercury thermometer was invented by physicist Daniel Gabriel Fahrenheit in Amsterdam (1714). It consists of a bulb containing mercury attached to a glass tube of narrow diameter; the volume of mercury in the tube is much less than the volume in the bulb. The volume of mercury changes slightly with temperature; the small change in volume drives the narrow mercury column a relatively long way up the tube. The space above the mercury may be filled with nitrogen gas or it may be at less than atmospheric pressure, a partial vacuum. In order to calibrate
Candy thermometer models have markers for the various stages of sugar cooking. A candy thermometer is similar to a meat thermometer except that it can read higher temperatures (usually 400 °F/200 °C or more). The first candy thermometers were created in 1272 by Bennet Muzilla of Frankfurt, Germany. He used it to measure the temperatures of sugar solutions while making hard candies. Candy thermometer A candy thermometer, also known as a sugar thermometer, or jam thermometer is a cooking thermometer used to measure the temperature and therefore the "stage" of a cooking sugar solution. (See Candy making for a description of sugar