(Hochstetter, Carl von) The mirror-sextant, a useful instrument for the engineer. 3 Bll., 18 p. With 4 folded copper plates by Balthasar Friedrich Leizelt. 22.5 x 18.5 cm. Simple cardboard tape d. Z. (cover flaky, faded and with library signs, back renewed). ==References== Fr. Cotta, 1794. VD18 11416211. Hamberger-Meusel III, pp. 357 and XIV, p. 149. Ersch, literature of mathematics... Sp. 101, No 891. Not with Engelmann, Grewe, Poggendorff, Roller-Goodman and Gradmann, Gel. Swabia. – Only edition. The author from Swabia (ca. 1760-after 1810) was a Russian-Kaiserlicher Hauptmann at that time and with his treatise wants to bring the sextants also to the (military) engineer. In 6 chapters he deals with the invention, the technical description, the mathematical explanation, the geometric use, the advantages before other instruments and the benefits for the engineer. The copper by the Augsburg artist Leizelt with 2 side views of a sextant as well as schematic measuring examples. The preface dates from "Warsaw on Green Thursday 1795." From the Princely Library Donaueschingen (Deed with biblical sign by Joseph von Laßberg). – Copper cut to the border line and mounted on strong paper.