RIDLEY, Mark (1560-1624). A Short Treatise of Magneticall Bodies and Motions. London: Nicholas Okes, 1613. Small 4° (172 x 124 mm). Engraved title by Renold Elstrack, engraved hand-coloured portrait, 21 engravings in text (one with two maps showing New England, Virginia and Terra Australis), another with the volvelle, woodcut initials, printer's woodcut device on verso of last leaf X3. (Lacking first and final blank, title lightly spotted, closed clean tear in Q2, margins cropped, sometimes affecting headline, also affecting outer and lower margin of title, light marginal browning.) Modern old-style calf, lettering-piece, gilt decorated spine.
FIRST EDITION, FIRST ISSUE, without the errata on X3r. Ridley, following William Gilbert's work De magnete, 'here presented directions for a series of experiments on the lodestone, magnet, and terella which could be carried out by anyone interested in the subject. He added engravings and descriptions of his improvised instruments for determining the variation, and for making use of the inclinatory needle for finding position at sea. This was in accordance with the method published jointly by Edward Wright, Thomas Blundeville and Henry Briggs' (Taylor). Johnson Astronomical Thoughts in Renaissance England 235-38; Mottelay Bibliography of Electricity and Magnetism 97; Sabin 71297; STC21045; Wheeler Gift 86.