[Anglicus (Robertus)] Astrolabii quo primi mobilis motus deprehenduntur canones,gothic type, 62 woodcut illustrations, woodcut initials, very light water-staining, title ink-spotted and with old ownership inscription, bound in 14th century vellum from a legal codex, worn and stained at edges, [BMC V, 458; Goff A-1171], small 4to, [Venice, Paganinus de Paganinis, c. 1497]. The work comprises two parts; the first, commonly known as Astrolabij canones is a treatise on the planispheric astrolabe, once attributed to Robert the Englishman (fl. 1271), but now recognised as the work of Robert of Chester (fl. 1144-50), who may or may not be the same person as Robert of Ketton (fl. 1141-57); the text of this first part of the book was originally printed in Perugia in c. 1477 (Goff R-203). The second part, printed here for the first time, is a very important treatise on surveying, De mensurationibus rerum. It is profusely illustrated with sixty-two woodcut diagrams, showing techniques for the measurement of altitudes (including using an astrolabe), angles and distances. The author of the first text, Robert of Chester, wrote a number of scientific treatises and translated Arabic works such as al-Khwarizimi's Algebra, made while he was in Segovia in 1145. As well as the work on the use of the planispheric astrolabe, he also wrote an original treatise on the construction of the universal astrolabe whilst in London in 1147. For the history of the book trade this edition is of particular interest because it was one of the first to be sold off; numerous copies were still unsold in 1512, and Petrus Liechtenstein re-issued the work by completing the title with three lines and adding the new date.

***Rare first complete & illustrated edition. One of the first books illustrating scientific equipment and certainly the first showing woodcuts of geodetic instruments. "The book is of the greatest importance in the history of astronomy and navigation, for it is one of the earliest by which the Astrolabe and its use were made known to Western Europe, and because it is directly based on Arabic sources" (Reichner 9, 166)..