What Is a Mercury-In-Glass Thermometer?
A mercury-in-glass thermometer is a thermometer which provides temperature readings through the expansion and contraction of mercury inside a calibrated tube. These devices were used extensively to measure temperatures in a wide variety of settings from the 1700s until the 20th century, when concerns about the health risks of mercury exposure led many nations to place restrictions on mercury-in-glass thermometers. Medical use of these instruments is largely banned, with remaining manufacture of mercury-in-glass thermometers being aimed primarily at meteorological researchers.
