Term: beckman thermometer: a mercury thermometer that measures small differences or changes in temperature
Broader: mercury thermometer: thermometer consisting of mercury contained in a bulb at the bottom of a graduated sealed glass capillary tube marked in degrees Celsius or Fahrenheit; mercury expands with a rise in temperature causing a thin thread of mercury to rise in the tube | Unrelated: mapmaking: the making of maps and charts
Broader: mercury thermometer: thermometer consisting of mercury contained in a bulb at the bottom of a graduated sealed glass capillary tube marked in degrees Celsius or Fahrenheit; mercury expands with a rise in temperature causing a thin thread of mercury to rise in the tube | Unrelated: zoysia: any of several creeping grasses of the genus Zoysia