I am seeking any information on Ferdinand Berthoud, clock - and watch maker, Paris, mid-1700's to 1807. His work was continued by his nephew, Louis Berthoud. Ferdinand was known for his work in the field of marine chronometers. I have a very old chatelaine watch signed by this maker. As best as I can describe it, heavy gold, diamonds, several enamels with enameling on the back of the watch. It's beautiful (if a bit gaudy) and quite heavy. If I am understanding correctly, this was worn by a man on his waistband. This watch was supposedly awarded to my ancestor by . . "the king of France". In the time period, I suspect this would have been Louis XVI. I've narrowed the time to: 1780-1791. Louis XVI lost his head (sorry) in 1792. I suspect royal or official records may have been lost due to the French Revolution. Thanking you in advance, JuliW I've attempted to attach a photo, hope it works.