Page 18 of Souveraine Collection by F.P.Journe

the deadbeat seconds device or the art of making time stand still towards the late 17th century as clocks were becoming increasingly precise watchmakers added a hand finally enabling them to measure seconds these clocks which became pendulum clocks thanks to the invention of the pendular balance by the dutch watchmaker huygens were almost naturally equipped with a 1 metre-long balance with a period of 1 second the dial was marked out into 60 subdivisions so that the hand could jump from one second to the next when the first watches indicating seconds were made some 18th century watchmakers wanted to achieve the same visual effect as on clocks to do so they invented systems extending the period of the balances the best-known being the crown-wheel escapement with pendulum or the huge balance by mr pouzait nonetheless these systems were rapidly abandoned since they were detrimental to precision thus without an additional system the hand started to beat out the half-second the most widespread frequency of the time the extreme ease with which time could be read off by a hand beating the seconds without moving during this same second gave 19th century watchmakers some new ideas three systems known as deadbeat seconds came into use the first consisted of a small additional gear train activated by a spring connected to the mainspring each second the hand was released by the watch escapement this so-called independent deadbeat seconds offered the advantage of not affecting the precision of the watch and could be disconnected at will by the user the second comprised an additional gear-train running from the escape-wheel to an additional seconds wheel equipped with 60 teeth held by a spring this extremely simple system was extremely prejudicial to precision in the third a so-called single-beat escapement waited for the balance to complete two oscillations in order for the escape-wheel to move forward every second these escapements were extremely popular in watches produced in china since according to chinese philosophy this corresponded to making time stand still the latter was no longer in control since it was mastered by the wearer finally today the tourbillon souverain is equipped with a natural deadbeat seconds device the latter is mounted on one of the wheels of the constant-force device and cannot in any way affect the precision of the watch françois-paul journe 67

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