A young man [from 'The School of Athens']

A photograph of a drawing by Carlo Maratti now in the Royal Library at Windsor Castle (RCIN 904255). The drawing reproduces the young man leaning over to the right, pointing with his left hand as he discusses geometry with others pupils of Euclid (or Archimedes) in the lower right corner of Raphael's 'School of Athens', painted in c.1509-10 in the Stanza della Segnatura in the Vatican.