Philippe Wurtz GRAMAT

The GRAMAT beautifully reinterprets historical observatory chronometers.  Similar to its most accurate forerunners, the GRAMAT has a gravity escapement.  However, in a departure from all previously known escapement designs, the pendulum of the GRAMAT is not in contact with any mechanical element like a spring, lever or anchor. The impulse required to drive the seven kilogram Invar pendulum is provided by very little displacement of its suspension axis.

Philippe Wurtz further innovates in the GRAMAT by housing the clock in a sealed chamber in which the density of the air is regulated.  Through study, it was determined that it is the density, not the pressure, of the ambient air that affects the accuracy of the clock. This forward-thinking approach to an historical challenge delivers a further degree of accuracy in the performance.

The GRAMAT is the first precision pendulum clock to combine a four-month power reserve, detached escapement, central seconds hand, and uninterrupted operation during rewinding via epicycloidal gearing.  These technical achievements are exquisitely showcased in a transparent tall case.