Exceptionally rare and important mahogany four-day going Chronometre Compte Secondes. Breguet, circa 1870
Breguet, No. 1149, sold to Bureau de Longitude circa 1870 for 2400 francs. Exceptionally rare and important mahogany four-day going Chronometre Compte Secondes with 4-day power reserve indicator for the going train and 8-hour power reserve indicator for the dead-seconds Break-Circuit train (Survey and Mother Clock). C. Rectangular, mahogany, hinged door at the back, gilt bun feet with additional four at the back door for working in a horizontal position, ivory pushbutton at the top for engaging or disengaging the Mother Clock. D. Silvered, set at the top of gilt plate, Roman numerals, outer minute track, winding indicator at 12 o'clock, subsidiary seconds, sector with winding indicator for the Mother Clock below. Blued steel "Spade" hands. M. Going train: 89 mm. , brass, circular, reversed fusee with maintaiing power and chain on single bridge, train and escapement on separate circular plate, Earnshaw type spring detent escapement, bimetallic compensation balance with two circular sliding temperature weights, free-sprung blued steel helical balance spring with terminal curves, escapement jeweled and capped, diamond endstone on the balance, additional pivoted detent for controlling seconds-beating mechanism activated by unlocking action of the escapement, mechanism disengaging the seconds-beating trin when the going train power goes to zero. Dead-seconds Mother Clock movement: rectangular, brass, fusee with maintaining power and chain, X-shaped jeweled fly with finely adjustable momentum of inertia, controlled by the pivoted detent from the going train meshing with contact breaker wheel giving impulse once a second, whose width is controlled by a knurled knob, self-cleaning contacts. Signed on the dial. Dim. Height 28 cm. , width 19 cm. , depth 13 cm.
Clock types
