JACQUINOT, DOMINIC

LAEUSAIGE DE LAEASTROLABE, AVEC UN TRAITU' DE LA SPHERE. PARIS: JEHAN BARBU', [1545].

      FIRST EDITION 4to. [viii], 84 ff., including errata. Text within ruled borders, woodcut printer's device (Renouard 31) on title, and woodcut of an astrolabe on colophon. With 38 exquisite woodcuts, including a large volvelle (a small area repaired affecting a few letters on verso supplied in a contemporary hand). Later half-vellum and marbled boards; insignificant worming last couple of leaves. Ex libris bookplate of Harvard College with small release stamp. Overall a fine copy from the library of Frank S. Streeter, with his bookplate. First edition of the first treatise in French on the astrolabe, a work of considerable historical importance, and exceptionally rare in its first printing. Divided into two parts, the first describes the specific functions of the astrolabe and its application in forty-three propositions. Among the author's numerous observations are detailed measurements of various celestial phenomena such as the height of the sun in both equal and unequal hours; directions to find longitude and latitude using both the sun and moon, which includes a detailed description of a lunar eclipse; and probably one of the earliest, if not the earliest printed text describing in detail a spring watch for ascertaining longitude. Jacquinot notes the writing of Regiomontanus and his teacher Puerbach on the armillary astrolabe and their observations on the sun's motion as well as that of the fixed stars and planets.The second part covers the geometry of distance, height and surface measurement, with varied applications to architecture, travel, fortification and sieges. Jacquinot's ingenious technical improvement in the design of his astrolabe is described in detail. Of great significance is what appears to be his combining different elements of the three basic azimuth instruments used by surveyors, which historians have heretofore credited to Digges in his later Pantometria (1571). Particularly important is Jacquinot's geometrical square, or quadrant, which contains an altimeter, built on the back of his astrolabe, and used for surveying. He here illustrates the heights of a tower, the length of a field, as well as the depth of wells, cisterns or trenches. In addition he also describes the use of optics for measurements..Little is known of Jacquinot (fl. 1545), who was from the Champagne region of France. The technical nature of this treatise suggests that he was an instrument- maker, and that the present work describes his first instrument, with a complete set of instructions. The book is dedicated to Catherine de Medici, then Dauphine, "who in her scientific knowledge not only surpassed contemporaries of her own sex, but also most men." Apparently Jacquinot, not intending to publish, presented it to her in manuscript; in the preface, he explains that it was only after he learned that several incorrect copies were made from the manuscript that the decision to publish was made. It was also likely that he was acquainted with the circle of nobility, as he was able to solicit the advice of Pascal Duhamel, the renowned Professor Regius of mathematics in Paris. Of equally great significance to this book is the type designed by Claude Garamond. From 1545, Garamond cut his Roman type, and according to both Updike and Mortimer, the Roman here was one of the first to appear in a printed book. In the same year, Garamond became his own publisher, featuring his own types, including a new italic. As a publisher, he modeled his book publishing style after the classic works of the Venetian printers who catered to the absolute elites of high society. Therefore, it was logical that Garamond would have collaborated with Jehan Barbe to publish the present book, one of the few printed in that first year of 1545. Garamond typefaces are considered the typographical highlight of the sixteenth century (see Beatrice Warde, The Types Garamond, translated from the Spanish).