Johann Georg Tralles

Johann Georg Tralles (1763 to 1822) was a German mathematician and physicist born in Hamburg. He studied at the University of Göttingen from 1783, became a professor at the University of Bern in 1785, and in 1810 took the chair of mathematics at the University of Berlin. In 1798 he served as the Swiss representative to the French convocation on the metric system and sat on its committee on weights and measures; the iron Committee Meter, a duplicate of the prototype archive meter, was later given to Ferdinand Rudolph Hassler, with whom he worked on a survey of the Canton of Bern from 1803 to 1805. He discovered the Great Comet of 1819, which bears his name, and invented the alcoholometer for measuring the alcohol content of a liquid. A lunar crater and the instrument are both named after him, and he died in London in 1822.