BREGUET ET FILS [ 寶璣] | A LARGE GOLD RUBY CYLINDER SINGLE HANDED WATCH NO. 3337, 'MONTRE DE SOUSCRIPTION' SOLD TO MONSIEUR CALISTE CASSON ON 2 JULY 1819 FOR 888 FRANCS [ 大型黃金單指針懷錶備紅寶石工字輪擒縱機芯，編號3337，1819年7月2日以888法郎售出]

Monsieur Caliste Casson

Breguet devised the Souscription watch series to aid the recovery of his business after he fled to Switzerland during the French Revolution. Characterized by their single hand, Breguet described these pieces as watches of the highest quality made to a single specification. Breguet required the purchaser to pay a third of the price in advance, thus begetting the name 'souscription.'

Breguet incorporated his newly invented modification to the cylinder escapement to this series of watches. Originally invented in the 1720s, the cylinder escapement was modified by Breguet to reduce the effects of its greatest failing, the fact that it was a frictional rest escapement. By making the cylinder out of ruby, it enabled the friction and wear of the escapement to be reduced to a minimum. English makers had already employed this device but as it was part of the arbor, it remained fragile and vulnerable. Breguet isolated the half section of cylinder from its balance axis thereby ensuring that it took no weight from the balance and was not susceptible to shocks. The balance was mounted on the lower collet of a conventional staff and the cylinder's pivot was supported by an arm mounted to the movement plate (for further information and technical drawings see G. Daniels, The Art of Breguet, 1975, p.302-303 and pls. 381-383).