Ca. Ø52mm, ca. 88g, original silver case, serial number 139692, precision lever movement according to patent Louis Wille Pat-No. 68208, movement number 315150, patented lever escapement, so called 'Doppelanker', fine adjusting device, signed enamel dial, in excellent condition, blued steel hands, dial signed: Andreas Huber Uhrenfabrik Urania 'Doppel-Anker-Uhr', in working order, in excellent condition with signed original box. Provenance: Mondani Collection, auctioned in Geneva for 6,490 Swiss Francs in 2006. Literature: Christoph Prignitz: 'Doppelanker, eine Taschenuhr mit seltener Technik'. According to this, there are only 5 known examples of this watch. The purpose of the patent was to protect the oscillating system against shocks in a way that is not found on any other lever escapement.