Mercury-in-glass thermometer and public health by decreasing the amount of mercury waste released. The HPA had, in 2007, released a guide to dealing with small spills of mercury. In the United States, both the American Academy of Pediatrics and the United States Environmental Protection Agency recommend that alternative thermometers be used in the home. 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.
Galileo thermometer Galileo thermometer A Galileo thermometer (or Galilean thermometer) is a thermometer made of a sealed glass cylinder containing a clear liquid and several glass vessels of varying density. As the temperature changes, the individual floats rise or fall in proportion to their respective density and the density of the surrounding liquid. It is named after Galileo Galilei because he discovered the principle on which this thermometer is based—that the density of a liquid changes in proportion to its temperature. Although named after the 16th–17th-century physicist Galileo, the thermometer described in this article was not invented by him. Galileo did invent