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
Miller-Casella thermometer the ocean was always warmer than that below. Scientists aboard the HMS Challenger later questioned this assumption and made temperature measurements with reversing thermometers instead which wouldn't require the coldest water to be at the ocean's bottom. Nature article - Miller Casella thermometer Miller-Casella thermometer The Miller-Casella thermometer was a Six's thermometer with a double bulb used extensively by the "Challenger" expedition during the late nineteenth century. The thermomemeter was used for water temperature readings along 360 different research stations around the world's oceans. The thermometer, about 9 inches in length, was enclosed in a copper case and filled with