An interesting, attractive and very rare print depicting a remarkable universal clock purportedly developed by Nuremburg clock- and watchmaker Zacharias Landteck (1670-1740). Not to be confused with the vastly more common version attributing the clock to map- and instrument maker Johann Baptist Homann.
The print depicts one face of Landteck’s clock, flanked left and right by German- and Dutch-language explanations and examples of its operation. At the center of the face is a polar projection of the Northern Hemisphere, which on the actual instrument was a fixed “northern terrestrial hemisphere made of enamel, which strikingly protrudes with its diameter of approximately 10cm.” (Dolz, pp. 36-7) This hemisphere is surrounded by concentric, rotating hour and calendar rings and partially covered by a rotating hemisphere of dark-colored glass, representing nighttime. In aggregate the clock enabled the user to determine the local time along any meridian, as well as the positions and times of sunrise and sunset on any day of the year for any location in the Northern Hemisphere. Thus, among other things, the clock demonstrated the essential role of time in ascertaining longitude.
The Universiteit Utrecht attributes the print to Johann Baptist Homann, with a tentative publication date of ca. 1705. This makes sense: the image of the clock, the style of engraving and coloring closely resemble that on the print Johann Baptistae Homanns Neu inventirte Geographische Universal-Zeig und Schlag-Uhr, which describes Landteck as the builder rather than the inventor. The obvious puzzle, not remarked on by Dolz, is why Homann would in one case attribute the invention to Landteck while in the other reserve credit to himself! The relative priority of the two prints is unclear, but in any event ours is far, far rarer: I find record of but one impression having appeared on the antiquarian market, offered by Jonathan Potter in 1994.
Dolz mentions but a single extant example of Landteck’s clock, apparently sold at auction in 1955, though he seems unaware of its current location. Indeed, for his article he was forced to rely on examination of a copy of the clock made in 1738 for Polish King Frederick August III. According to the Universiteit Utrecht’s description of its impression of this print, “For a long time it was assumed that there were no more copies of the world time clock of Zacharias Landteck. In 2005, however, the Musée International d’Horlogerie at La Chaux-de-Fonds (Switzerland) managed to acquire a copy for its collection.”
Not in OCLC. For background see Wolfram Dolz, “Johann Baptist Homann’s Geographic Universal Clock and the Small Globes of Sichelbarth and Doppelmayr.” Globe Studies, no. 51/52, 2005, pp. 33–45.