Gunter, The works, London, 1673, fifth edition, contemporary panelled calf

GUNTER, EDMUND

The Works... the fifth edition, diligently corrected, and divers necessary things... added... not before printed. By William Leybourn... London: A.C. for Francis Eglesfield, 1673

4to (197 x 153mm.), half-title, additional engraved title page, advertisement leaf, 3 folding plates, woodcut diagrams and illustrations, contemporary panelled calf, quires 3A⁴-3E⁴ (the first 40 pages of "The third book of the use of the lines of numbers, sines and tangents...", which has its own pagination) misbound at the end, joints cracked, spine slightly cracked, some slight damp-staining, some browning

Fifth edition of the works of the mathematician Edmund Gunter (1581-1626), including his most important and most influential work The Description and Use of the Sector, the Crosse-Staffe and other such Instruments (1623) which explained instruments which he had designed, a number of which became very popular. The Gunter sector allowed calculations involving square and cubic proportions, and carried various trigonometrical scales. Moreover it had a scale for use with Mercator's new projection of the sphere, making this projection more manageable for navigators who were only partially mathematically literate. The sector was sold as a navigational instrument throughout the seventeenth century and survived in cases of drawing instruments for nearly three hundred years. Gunter's cross-staff was unique in its inclusion of logarithmic scales, making it, in effect, THE FIRST VERSION OF A LOGARITHMIC RULE. It was from Gunter's work that logarithmic slide rules were developed, these remaining in use until the late twentieth century.

LITERATURE:

ESTC R14615; Wing G2241