clockmaking

Johann George Hartmanns, Universitäts-Mechanici und Klein-Uhrmachers zu Halle, Nöthiger Unterricht von Verbesserung Aller Uhren

Rare first and only edition of Hartmann's technical guide to clockmaking, issued together with an improved edition of his guide to constructing pocket-watches. The two works are embellished with 54 figures on 17 folding plates, not to mention the engraved portrait of the author, a resident clock-maker in Jena. Hartmann's third chapter is devoted to a subject evidently of wide contemporary interest — the application of clocks to astronomical measurements.