Lorenzo Mascheroni

Lorenzo Mascheroni (1750 to 1800) was an Italian geometer, priest and poet, born in Bergamo. He was educated to become a priest and was ordained at seventeen, then taught rhetoric and, from 1778, physics and mathematics at the Bergamo seminary. In 1786 he became professor of algebra and geometry at the University of Pavia, helped by his work on the statics of vaults, and in 1789 he became rector of the university for four years. In 1790 he calculated Euler's constant to 32 decimal places, although only the first 19 were correct, as Johann von Soldner showed in 1809. He is best known for Geometria del compasso (Pavia, 1797), dedicated in verse to Napoleon Bonaparte, in which he proved that every Euclidean construction can be made with compasses alone. The Danish mathematician Georg Mohr had proved the same result in 1672 without Mascheroni knowing it, so the result now carries both names. Sent to Paris in the late 1790s to study the new metric system, he was prevented by war from returning to Milan and died in Paris in 1800.