Page 6 of Collection Octa by F.P.Journe

the construction of the octa calibre has less powerful ties with the history of watchmaking than do the remontoir or the resonance models but it nonetheless symbolises an horological ideal of giving timekeepers the highest possible degree of precision and autonomy within this context one may mention jobst bürgi who used the remontoir to achieve three months of autonomy for his clock one might also note the fact that if church clocks are placed so high in addition to enhancing visibility it is mostly because it often took an entire month for the driving-weights to drop the full length of their cords many systems were invented to increase the duration of run of a watch meeting with various degrees of success given the small volume of a wristwatch the spring could not be as large as one might wish watchmakers therefore discovered the trick of placing an additional wheel inside the customary gear-train so as to extend the duration of its development unfortunately actually using this system even with a stronger spring led them to observe that the energy actually reaching the spring remained low to compensate for this they fitted a smaller balance using less energy but which nonetheless lost a considerable amount of stability it is therefore not unusual to find that some watches able to run for several days have an extremely unpredictable level of precision this challenge was a powerful source of motivation i then imagined that the best and also the most obvious solution to extend the duration of run would be to extend the capacity of the spring development the difficulty lay in integrating it on the same level as the gear-train and the escapement due to its size 1 metre long and 1 millimetre thick given the low torque of this spring i could achieve extremely fast automatic winding one and a half hours in a chappuis cyclotest for more than 5 days running with the challenge of autonomy now won through this automatic winding calibre i then knuckled down to the second challenge of inserting various complications into that same movement power-reserve with large date display fly-back chronograph with large date display retrograde annual calendar etc while maintaining exactly the same size on all models in the octa collection three years of research and more than two years of development were required before this automatic winding movement that is unique in the world could be presented to the public françois-paul journe

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