Johann Georg Tralles, German mathematician and physicist (b. 1763)
Johann Georg Tralles (15 October 1763 – 19 November 1822) was a German mathematician and physicist.
He was born in Hamburg, Germany and was educated at the University of Göttingen beginning in 1783. He became a professor at the University of Bern in 1785. In 1810, he became a professor of mathematics at the University of Berlin.
In 1798 he served as the Swiss representative to the French metric convocation, and was a member of its committee on weights and measures. An iron "committee" meter, a duplicate of the prototype archive meter, was then given as a gift to Ferdinand Rudolph Hassler. From 1803 until 1805 these two men worked together on a topological survey of the Canton of Bern.
In 1819, he discovered the Great Comet of 1819, Comet Tralles, named after him.He was the inventor of the alcoholometer, a device for measuring the amount of alcohol in a liquid.
He died in London, England. The crater Tralles on the Moon is named after him, as is the alcoholometer he invented.