Lorenzo Mascheroni May 13 1750 July 14 1800 was an Italian mathematician born near Bergamo Italy At first mainly interested in the humanities poetry and Greek language he eventually became professor of mathematics at Pavia In his Geometria del Compasso Pavia 1797 he proved that any geometrical construction which can be done with ruler and compasses can also be done with compasses alone However the priority for this result now known as the Mohr Mascheroni theorem belongs to the Dane Georg Mohr who published a proof already in 1672 In his Adnotationes ad calculum integrale Euleri 1790 he published a calculation of what is now known as the Euler Mascheroni constant He died in Paris