Ca. Ø52mm, ca. 95g, 18K gold, back with Art nouveau relief, dome marked ' Eidgenössisches Schützenfest St. Gallen 1904', extremely rare chronometer movement, special Rosat fine adjusting device, wolf's toothing, Ankerchronometer No.24026, patent numbers 24677/21639, tested at the Neuchâtel Observatory 1904, signed enamel dial, exceptionally beautiful steel hands, in good condition, case with small signs of use, in working order. Gold Observatory chronometers with marksman's cases are exceptionally rare and were often only made in very small numbers for these special events. Charles Rosat was born in Le Locle on 26 May 1874, the son of the watchmaker William-Charles-Frédéric Rosat and Louise Egger. He won several first prizes in chronometerpetitions as a regulator. On 3 November 1900, he was granted patent no. CH21639A / 'Coq avec piton porte-spiral mobile' and another patent no. 24677 of 22 February 1902 for his very special fine adjusting device. Shortly after, this mechanism was used in the watches of Georges Favre-Jacot & Cie, H. Moser & Cie and Caesar Racine. His good contacts with the Neuchâtel Observatory and his particular success in the chronometerpetitions led him to supply precision pendulum watches (PPU) to the observatory. He was asked to work on the observatory's clocks. For example, in the pendulum clock of Joseph Thaddäus Winnerl, the oxidised rust pendulum was replaced by a pendulum with mercurypensation. Furthermore, all the clocks were equipped with electrical contacts, five of them with the Charles Rosat system.