Giulio Carlo de' Toschi di Fagnano

Giulio Carlo, Count Fagnano, Marquis de Toschi (26 September 1682 — 18 May 1766)[1] was an Italian mathematician.

[clarification needed][2] Fagnano made his higher studies at the Collegio Clementino in Rome, and there won great distinction — except in mathematics, to which his aversion was extreme.

[1] Fagnano is best known for investigations on the length and division of arcs of certain curves, especially the lemniscate (cf.

Lemniscate elliptic functions); this seems also to have been in his own estimation his most important work, since he had the figure of the lemniscate with the inscription "Multifariam divisa atque dimensa Deo veritatis gloria" engraved on the title-page of his Produzioni Matematiche,[3] which he published in two volumes (Pesaro, 1750), and dedicated to Pope Benedict XIV.

The word "rectifiable" meant at that time that the length can be found explicitly, which is different from its modern meaning.