Johann Jacob SAUTER (1770 - early 19th century) Equinoctial sundial. Saint Petersburg, circa 1800. Steel and gilt bronze, enameled dial. 46.5 x 24 x 10 cm; weight: 3000 g Johann Jakob Sauter was the eldest son of Johann Jakob Sauter the Elder, a mechanical watchmaker and designer of an exceptional calculating machine that his namesake son seems to have completed. Of Sauter the Elder's four sons, only Johann Jakob moved to St. Petersburg around 1800 for a few years, before leaving for Stockholm where, as early as 1805, he built a planetary clock.