This lot is closed for bidding. Bidding ended on 10/12/2023
[HADLEY, John (1682-1744)]. The nature and use of Hadley’s quadrant, with a preface containing… a description of the nonius. [London?]: [s.n.], [between 1770 and 1800].
Small 4to (203 x 127 mm). Folding engraved frontispiece, unsigned (browning at gutter). (Title-page also a bit browned at gutter, marginal tear to C4). Full modern vellum.
A rare early work describing the use of the Hadley’s quadrant which was used by navigators to measure the angular elevation of the North Star of the Sun above the horizon in order to find one’s latitude. In 1730, Hadley, an English mathematician and Fellow of the Royal Society of London, laid claim to this invention of the octant (or quadrant) that would prove extremely valuable and would displace the use of other instruments in navigation such as the Davis quadrant. This edition lacks the imprint and has the plate that is unsigned such as the one that resides in the Library of Congress. ESTC N511135 (lacks imprint but calls for 35pp.); OCLC 63179179 (this copy, which calls for 24pp.).