Person: Mascheroni, Lorenzo
Lorenzo Mascheroni was a geometer who proved in 1797 that all Euclidean constructions can be made with compasses alone, so a straight edge in not needed.
Mathematical Profile (Excerpt):
 Mascheroni was educated with the aim of becoming a priest and he was ordained at the age of 17.
 In 1786 Mascheroni became professor of algebra and geometry at the University of Pavia, mainly on the strength of his excellent work on statics Nuove ricerche su l'equilibrio delle volte which he had published one year earlier.
 In Adnotationes ad calculum integrale Euleri (1790) Mascheroni calculated Euler's constant to 32 decimal places.
 Despite the error in the calculation, Mascheroni's work shows a deep understanding of Euler's calculus.
 Mascheroni is also known as a poet and he dedicated one of his books Geometria del compasso Ⓣ(Compass geometry) (published in Pavia in 1797) to Napoleon Bonaparte in verse.
 In this work Mascheroni proved that all Euclidean constructions can be made with compasses alone, so a straight edge in not needed.
 This had been (unknown to Mascheroni) proved in 1672 by a little known Danish mathematician Georg Mohr.
 For his excellent contributions Mascheroni received a number of honours such as election to the Academy of Padua, the Royal Academy of Mantua and to the Società Italiana delle Scienze.
 Mascheroni was appointed as a deputy in the governing legislative assembly in Milan in 1797.
 Mascheroni was sent to Paris to study the new system and to report to the governing body in Milan.
 Mascheroni was unable to return to Milan due to the war and the Austrian occupation of the city in 1799.
 One is left with asking whether Mascheroni deserves the credit for proving a result which Mohr proved 125 years earlier.
 The first question we must ask is whether Mascheroni might have known of Mohr's result.
 One is certainly led to believe that Mascheroni could not have known Mohr's proof but it is still possible that he had heard that the result had been proved earlier.
Born 13 May 1750, Bergamo, LombardoVeneto (now Italy). Died 14 July 1800, Paris, France.
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References
Adapted from other CC BYSA 4.0 Sources:
 O’Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive