IWC Schaffhausen DA VINCI TOURBILLON RÉTROGRADE CHRONOGRAPH Mode D'emploi page 21

— 2 1 —
error of the balance influences the accuracy, depending on the
position of the watch. Fortunately, there is a way to overcome this
problem caused by one of the basic laws of physics: the balance,
the pallets and the escape wheel are mounted in a minute cage
that rotates around itself once every minute. In this way, the effect
of the gravitational error is practically eliminated. To ensure that this
extraordinary watch continues to perform faultlessly in the future,
it is essential to observe a few important operating instructions.
D A V I N C I T O U R B I L L O N R É T R O G R A D E C H R O N O G R A P H