Bachelard was most probably of Swiss origin but hardly any information about this watchmaker can be found.
For the image of a pedometer movement signed Bachelard and dated around 1780, Exhibit No. 10,660 in the Arts et Métiers Museum in Paris see The History of the Self-Winding Watch by A. Chapuis & E. Jaquet, p. 170.
The invention of the self-winding mechanism goes back to the 18th century, at an epoch when portable timekeepers were still pocket watches. Around 1770, Abraham-Louis Perrelet of Le Locle, one of Breguet's early instructors, came up with the idea of maintaining a watch wound by using the energy generated by the movements of the person carrying it. Timekeepers equipped with such a system were called perpetual or pedometer winding watches.
To keep the watch wound, an oscillating weight, or rotor, connected to the winding system and functioning like a pendulum, its movements using the gear trains to wind the barrel spring.
It is thought that Breguet and the English watchmaker Recordon were amongst Perrelet's first customers. Breguet consequently made his first "perpétuelle" around 1780; he had improved Perrelet's mechanism by an eccentric arrangement of the oscillating weight, similar to the one used in the present watch.