$270
Ramsden, Jesse (1735-1800) Description d'Une Machine pour Diviser . Paris: Didot, 1790. First edition in French, large quarto, title page dusty and water stained, illustrated with seven large folding engravings bound after the text; original limp paper wrappers, stab sewn, untrimmed, with deckle edges throughout, marginal water stains to first thirteen pages of text. Ramsden was a maker of mathematical instruments; this work is a description of his "dividing engine," which was used to accurately scribe lines onto measuring devices like astrolabes, sextants, and protractors. Setting circles are the graded measurements etched onto dials on telescopes; these enable the observer to find objects in the sky by the equatorial coordinates used in celestial charts.
Auctioneer:
Skinner
Date:
2013-06-01