Later traditions may be read in Carpzov's Introductio, pars 3, cap. xvi.
They paid a fixed proportion of the produce (pars agraria) to the owner of the estate, and gave a determinate amount of labour (operae) on the portion of the domain which he kept in his own hands (mansus dominicus).
A preliminary study of optics led to the publication, in 1604, of his Astronomiae pars optica, containing important discoveries in the theory of vision, and a notable approximation towards the true law of refraction.
First of all Monsignor Bayardi was brought from Rome and commissioned to write about the antiquities which were being collected in the museum at Portici under the care of Camillo Paderni, and when it was recognized that the prelate had not sufficient learning, and by the progress of the excavations other most abundant material was accumulated, about which at once scholars and courtiers were anxious to be informed, Bernardo Tanucci, having become secretary of state in 1755, founded the Accademia Ercolanese, which published the principal works on Herculaneum (Le Pitture ed i bronzi d'Ercolano, 8 vols., 1757, 1792; Dissertationis isagogicae ad Herculanensium voluminum explanationem pars prima, 1797).
