Annulorum trium diversi generis instrumentorum.

Johannes Dryander. Annulorum trium diversi generis instrumentorum.

Illustrated with large woodcut of an armillary sphere on title-page and the divisional title to Regiomontanus; verso of title-page with a large woodcut of "Dryander's astronomical rings" suspended from a hand in the clouds; numerous woodcut illustrations and diagrams in text; woodcut printer's device on pi4v and verso of final leaf; several large historiated woodcut initials. Text in Latin (a few passages in Greek). Slim 4to. Modern ¼-vellum (using old material) over marbled boards; printed paper title-label in gothic script pasted on front cover. Printed in Marburg by Eucharius Cervicornus, 1537. First Edition of this important assembly of texts on a popular Renaissance astronomical instrument: the astronomical ring-dial, a precursor of the equatorial. (Adams D940; BM STC German p 255; Houzeau and Lancaster 2459; Honeyman Collection 930; Zinner 1661)


The ring-dial was intended as a navigational aid and could be adjusted for different latitudes, including, according to the author, the Moluccas and Hispaniola. The second part of the first treatise is entitled De metiendis rebus and is illustrated by various cuts showing geodetic performances. Around two thirds of Dryander's work is devoted to describing the parts of his new version of the instrument and its marking and calibration, as well as its use, including a lengthy section on measuring the heights of objects.


The main subject of this book, the so-called annuli astronomici, i.e., astronomical rings, was an early astronomical instrument, consisting of 3 rings, each representing the celestial equator, declination, and the meridian. The instrument may be considered a simplified, portable armillary sphere, or a more complex form of astrolabe. These ring instruments can be employed for both terrestrial and celestial calculations; they can also be used as a sun dial to tell time, if the approximate latitude and season is known, or to tell latitude, if the time is known. It also had applications in surveying. Parts of the instrument go back to devices made and used by ancient Greek astronomers.

Title page with 2 small repaired ink-burn holes causing a loss of a few words of the imprint (but the date is clearly legible), and slightly affecting the woodcut on verso. Occasional light soiling; several leaves with very light and unobtrusive water-staining at bottom, mainly marginal; o/w a clean, wide-margined example of this interesting and scarce book.