lorenzo mascheroni may july 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 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 in his adnotationes ad calculum integrale euleri he published a calculation of what is now known as the euler mascheroni constant he died in paris