FERNEL, Jean.

Monalosphaerium, partibus constans quattuor.

      Paris: Simon de Colines, 1526 [1527] - First Edition of Fernel?s first work. Though he eventually gave himself up entirely to medicine, his first three works dealt with the mathematical sciences. This first treatise deals with the motions of the heavens and describes a kind of astrolabe of Fernel's own design. Other subjects discussed include horology, astrology, geography and the measurement of distances and altitudes. The work includes an illustration of the "geometrical foot" (figuratio pedis geometrici), in the fore margin of fol. 25 verso. The geometrical foot is shown divided into 4 "palms", each of which consists of 4 "digits", each of which, in turn, consists of 4 "grains" (i.e. the width of a barley corn). Folio (322 × 217 mm), [6], 36 leaves; collates a?g6. Full modern limp vellum, manuscript title on spine. Title within elaborate historiated criblé border attributed to Oronce Finé; illustrated with numerous woodcut diagrams in text; many decorative metalcut and woodcut initials, mainly designed by Geoffroy Tory. Minor neat repair to inner margin of title and a couple of further preliminary leaves; some light spotting to margins of a few leaves; one letter written in ink (by way of correction) in inner margin of leaf b1v; a very good copy. [Attributes: First Edition]