In this illustration, Chérubin d’Orléans adopted the lunar map of Hevelius. The putti are observing the Moon with telescopes equipped with the “pantograph,” a perspectival tool devised by d’Orléans.
D’Orléans made models of the eye, complete with lenses. He experimented with different types of telescopic eyepieces, and devised a binocular telescope. This work provides a comprehensive theoretical and practical discussion of perspective, vision and optics. Part 1 covers the theory of vision, including the optics of the eye. Part 2 explores the theory of Galilean and Keplerian telescopes, as well as microscopes, and suggests practical improvements in their design. In Part 3, d’Orléans explains the best procedures for grinding and polishing lenses. An engraved frontispiece and 57 plates illustrate a variety of optical and perspectival devices.