ZAHN, Johannes (1641-1707). Oculus Artificialis Teledioptricus sive Telescopium. Würzburg: Quirinus Heyl, 1685-1686.

First edition, a remarkable copy in contemporary pigskin, of the most important seventeenth-century treatise on lenses and optics—rarely found complete as here with all the plates, tables, and text. This work is "a complete treatment of the construction and use of lensed optical instruments. Presented in three fundamenta, that is, bases: the physical, the mathematical, and the practical or mechanical" (DiLaura). It is also a significant step in the development of photography; the camerae obscurae described by Zahn are fitted with combinations of lenses that are the basic system of our photographic cameras today. Among the copious illustrations are an early map of the moon, based on Chérubin d’Orléans, a map of the sun showing sunspots and eruptions on the surface, and a depiction of the geocentric system.

"In his Preface to the reader, Johannes Zahn adopts the word 'Teledioptrica' to indicate generally the art, craft, science, and practice of using lenses to extend, enhance, and correct vision. For Zahn, teledioptrics includes magnification by telescope and microscope, vision correction by spectacles, image capture by the camera obscura, and image projection by the magic lantern. He cites the benefits that teledioptrics has brought to man in peace, war, natural philosophy, economy, and medicine. And so, he makes clear the purpose and reason for his book: to describe in a full and complete form, all aspects of teledioptrics" (DiLaura). This copy includes an additional five early 18th-century manuscript leaves in Latin and German of learned notes, including optical tables and details. The notes refer to important optical theorists Chérubin d'Orléans, Claude François Milliet Dechales, and Christian Gottlieb Hertel. This copy is complete; although auction records occasionally refer to "8 of 11 folding tables," this is an error traceable to the Norman copy, which was erroneously described as having 11 tables in these rooms in 1989. DiLaura 192.

Three volumes bound in one, folio (314 x 196mm). Title pages to each volume printed in red and black. Engraved portrait frontispiece and additional title at front; engravings and woodcuts in text, with 2 double-page plates in vol 2 and 28 plates in vol 3, 2 double-page and one large folding plate; 8 letterpress tables (pl. opposite p.121 detached, browning and spotting, some small marginal tears, large folding plate with old repair). Contemporary blindstamped pigskin over beveled wooden boards, copper tabs marking vols 2 and 3, blue edges, straps (without catches, small area of leather missing from rear board). Provenance: Reichersberg Abbey, with old shelfmark on front pastedown and oval stamp on titles.