Daniel Gabriel Fahrenheit, also called Gabriel Daniel Fahrenheit (May 24, 1686 - September 16, 1736), was a physicist and an engineer, who most of his life worked in Netherlands and for whom the Fahrenheit scale of temperature is named.
Fahrenheit was born in Danzig (Gdansk), in Polish province of Royal Prussia. He was the son of businessman Daniel Fahrenheit and Concordia Fahrenheit (widowed name Runge), who was the daughter of the well-known Gdansk business family Schumann. Of the five Fahrenheit children who survived childhood (2 sons, 3 daughters), Daniel was the oldest. The Fahrenheits naturalised to Gdansk in 1650 when Daniel's grandfather Reinhold Fahrenheit vom Kneiphof of Königsberg settled there as a businessman. Research suggests that the Fahrenheit family originated in Hildesheim, although they lived in Rostock before moving to Königsberg.1
Upon the early death of his parents he had to take up business training. However, his interest in natural sciences caused him to take up studies and experimentation in that field. Fahrenheit's studies brought him to Amsterdam, where he gave lectures in chemistry. In 1724 he became a member of the Royal Society.
He developed precise thermometers. The Fahrenheit scale was widely used in Europe until a switch to the centigrade or Celsius scale. It is still used by the general population for everyday temperature measurement in the United States.
When he first made his thermometers, he used alcohol instead of mercury. Later he used mercury, which gave better results.