[28], 120 pp. (a4, b6, c4, A-P4). With 12 folding copper-engraved plates of diagrams, etc. (4to) 19.8x16 cm. (7¾x6¼"), original(?) parchment-backed marbled boards. First Edition.
Rare first edition of this important work on geometry and mensuration by the German mathematician Michael Scheffelt (1652-1720), who is perhaps most noted for the invention of a measuring stick. Included are scales for arithmetic, trigonometry, geometrical drawing and the military scales for fortification and solving the caliber problem. The work proved popular, going through several editions until at least 1755. Scheffelt was a mathematics teacher in Ulm who eventually became a professor at the university there; he also seems to have sold a variety of scientific instruments. Laid into this copy is a 22-page copybook apparently for a physics class, dated Landau, 1915-16. Included in it are pencil drawings of workings of an electric light bulb, a vertical meter, electromagnet, electric bell, Morse telegraph, microphone, telephone, spark coil, Rontgen’s x-ray machine, air waves, water waves, phonograph, etc., with descriptions in German. There are what appear to be teacher comments on some of the drawings (“V Gut” – “very good”). No copies of the Instrumentum Proportionum have sold at auction since at least 1975, according to American Book Prices Current. Old ink name(?) on title-page ("Sickenberg Oberlieute" ?).
Condition:
Boards rubbed, old ink writing on the parchment spine; some light foxing and aging to contents, old ink writing crossed out on front pastedown; very good or better.