L’optique. Divisée en trois livres où l’on démontre d’une manière aisée tout ce qui regarde 1\o. La propagation et les proprietez de la lumiere, 2\o. La vision. 3\o. La figure & la disposition des verres qui servent à la perfectionner.

Paris: chez Estienne Michallet, 1682.

First (only) edition.

Ango, a French Jesuit, was professor of mathematics at his native town of Rouen. His only other work, Pratique générale des fortifications (1679) has a privilège which mentions two other works: Du mouvement d’ondulation; and De la dioptrique. These titles do not seem to exist and perhaps both are incorporated in the present book.

This copy has two previously unrecorded leaves of errata at the end. The errata are headed by an apology from the author saying that a large part of the book was printed off without his knowledge, so that several sections which he had meant to add have not been printed. In addition there are many significant errors which the reader is asked to correct before reading the book.

Ango’s treatise is of significance to the history of optics because it established the outline of a wave theory of light nearly eight years in advance of Huygens’ Traité de la lumière (1690). Both Ango and Huygens, acknowledged making use of an unpublished manuscript by the Jesuit scientist Ignace Gaston Pardies (1636–1673) which may have suggested a wave theory based on optical experiments with reflected and refracted rays. (Becker.)