GREGORY, James (1638-1675).  Optica Promota, seu abdita radiorum reflexorum & refractorum mysteria, geometrice enucleata.  London: J. Hayes for S. Thomson, 1663.
GREGORY, James (1638-1675). Optica Promota, seu abdita radiorum reflexorum & refractorum mysteria, geometrice enucleata. London: J. Hayes for S. Thomson, 1663.

Details
GREGORY, James (1638-1675). Optica Promota, seu abdita radiorum reflexorum & refractorum mysteria, geometrice enucleata. London: J. Hayes for S. Thomson, 1663.

4o (184 x 137 mm). Numerous woodcut diagrams. (Some minor browning to text.) Contemporary mottled calf, spine gilt.

Provenance: Pierre Varignon (1654-1722), mathematician and physicist who played an active role in the initial development of the principle of the composition of forces (see DSB); "ex dono amici de V." (early inscription on title); late 17th-century French notations on front pastedown mentions Gregory's telescope; C. Filippo Linati (bookplate).

FIRST EDITION of Gregory's contribution to the development of the telescope. In this work "Gregory explained how the deficiencies in the conventional pure reflectors and refractors stimulated him to design a compound 'catadioptrical' telescope, in which a large paraboloidal concave, which in turn formed the final image in the center of the main speculum" (Norman). Wing G-1912; Norman 942.

[Bound with:]

WALLIS, John (1616-1703). Tractatus duo. Prior, de cycloide et corporibus inde genitis. Posterior, epistolaris; in qua agitur, de cissoide, et corporibus inde genitis: et de curvarum. Oxford: Typis Academicis Lichfieldianis, 1659.

4o. 3 folding engraved plates. FIRST EDITION of Wallis's treatises on the cycloid and cissoid arcs inspired by a competition held by Pascal in 1658, asking for quadratures, cubatures and centers of gravity of certain figures inscribed by cycloidal arcs. Wing W-612; Norman 2180.