Daniel Gabriel Fahrenheit temperature scale to be widely used). In other words, Fahrenheit's inventions ushered in the first revolution in the history of thermometry (branch of physics concerned with methods of temperature measurement). From the early 1710s until the beginnings of the electronic era, mercury-in-glass thermometers were among the most reliable and accurate thermometers ever invented. Fahrenheit was born in the city of Danzig (Gdańsk), Pomeranian Voivodeship in the Polish–Lithuanian Commonwealth, but lived most of his life in the Dutch Republic. The Fahrenheits were a German Hanse merchant family who had lived in several Hanseatic cities. Fahrenheit's great-grandfather had lived in Rostock, and
Mercury-in-glass thermometer period of time, typically 24 hours. The original design contains mercury, but solely as a way to indicate the position of a column of alcohol whose expansion indicates the temperature; it is not a thermometer operated by the expansion of mercury; mercury-free versions are available. Mercury thermometers cover a wide temperature range from ; the instrument's upper temperature range may be extended though the introduction of an inert gas such as nitrogen. This introduction of an inert gas increases the pressure on the liquid mercury and therefore its boiling point is increased, this in combination with replacing the Pyrex glass