1851
- On 1 January the name of Patek & Co. is changed to Patek Philippe & Co..
- On 7 January the councilmen of Grenchen at the instigation of Dr. Josef Girard decide to start the building of a watch industry.
- Jules-Louis Audemars is born on 28 March in Le Brassus.
- Foucault demonstrates the rotational movement of the earth using the pendulum.