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
Six's thermometer in the push-button type with the magnetic plate in place, there is a risk of damaging the weak magnet behind the scale, or magnetising the steel in the markers either weakening or enhancing the pulling force against the capillary tube on all or part of the scale so that the thermometer no longer works properly. The original Six's thermometer design contains mercury, which has been banned for most uses in the European Union and some other parts of the world. In 2006, S.Brannan & Sons Ltd, a UK company, was granted a patent for a mercury-free version of Six's maximum–minimum