Glossary

The differential is a gear system, which is mainly found in watches with more than one escapement, such as double balance wheels or double tourbillons. Its main function is to provide an average between two different rates of timekeeping. It helps ensure accurate timekeeping in watches that have more than one escapement by averaging the rates of the different escapement wheels, which ultimately contributes to the watch's overall accuracy and functionality.

The differential is constructed using conical gears that connect the two shafts, facilitating the transfer of energy from the faster side to speed up the slower one while maintaining an overall energy balance. This mechanism was originally invented in the 1830s by a French engineer.