‘A treatise on optics' by Giovanni Christoforo Bolantio

Few accounts have survived detailing the techniques employed for the production of optical glass for astronomical and microscopical instruments during the seventeenth century in Italy; the period during which the art was being developed in the shops of Eustachio Divini and Giuseppe Campani, and other optical instrument-makers. Indeed, few of the tools of the lens-makers have been described in any detail, and few if any have survived. Consequently, the discovery of a hitherto apparently unknown Italian treatise, or what appears to have been notes for a shop manual of the period, is a contribution to present knowledge of lens-making technology even though the identity and region of the author remain unknown.