FERDINAND BERTHOUD & JEAN MARTIN, PARIS | A VERY RARE AND FINE EARLY BRASS CASED MARINE CHRONOMETER1795, NO. 64

• Movement: gilded full plate, early spring detent• Dial: brass dial/top-plate, silvered subsidiary chapter ring for hours and minutes, outer chapter ring with Arabic seconds ring, blued steel hands, signed and numbered Fd. Berthoud Invt., Jn. Martin Exéce. 1795 and numbered 64• Case: brass bound case with hinged gilt-metal bezel, glazed hinged back, broad bezel

Dial: Some spotting and light scuffs to the silver chapter rings. Some tarnishing to the hands Case: wear to the gilding. Pitting to the case throughout. Movement: The movement is not running, balance rotates. Slight tarnishing.
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. All dimensions in catalogue descriptions are approximate. Condition reports may not specify mechanical replacements or imperfections to the movement, case, dial, pendulum, separate base(s) or dome. Watches in water-resistant cases have been opened to examine movements but no warranties are made that the watches are currently water-resistant. Please note that we do not guarantee the authenticity of any individual component parts, such as wheels, hands, crowns, crystals, screws, bracelets and leather bands, since subsequent repairs and restoration work may have resulted in the replacement of original parts. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue. In particular, please note it is the purchaser's responsibility to comply with any applicable import and export matters, particularly in relation to lots incorporating materials from endangered species.NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."

**Please be advised that bands made of materials derived from endangered or otherwise protected species (i.e. alligator and crocodile) are not sold with the watches and are for display purposes only. We reserve the right to remove these bands prior to shipping."

Ferdinand Berthoud (1727-1807) was born in the Swiss Jura and left for Paris following a three year apprenticeship to his brother, Jean Henri.   He received the title of Master Watchmaker in 1754, and dedicated the rest of his life to studying and developing accurate marine chronometers. In 1764, he received the title of Horologer de la Marine; a post particularly esteemed at a period when the race to construct a timepiece capable of finding longitude at sea was of critical importance. 

King Louis XV appointed him to visit London to observe John Harrison’s famous H4. Harrison, suspicious that Berthoud would use his knowledge for the benefit of the French Navy, only showed him H1, H2, and H3. Regardless of this set-back, Berthoud established several key relationships on this trip, and on his second visit in 1765, met with Thomas Mudge, who described the working principles of H4 without showing it to him.

Berthoud returned to France with an understanding of the new British technology, and designed two marine clocks which were successfully used on a number of voyages by the French Navy. From then on, he produced all marine clocks and watches used on the King's ships, dedicating nearly 50 years to the study of accurate marine chronometers. He experimented with multiple design variants, beginning early on with weight driven chronometers, and then moving to spring-powered chronometers.  He later built compensating mechanisms into the balance itself. In all, Berthoud produced between 70 and 80 marine chronometers, of which several important examples reside in the Conservatoire des Arts et Métiers, in Paris. For detailed information on Berthoud's life and work see Hans Von Bertele, Marine and Pocket Chronometers, pp. 42-43, and Rupert T. Gould, The Marine Chronometer, pp.126-166.

Jean Martin worked as Berthoud’s student for many years, before establishing himself as a naval watchmaker in Brest in 1785.  In 1793, two years before the creation of the present lot, he returned to Berthoud’s workshop, and continued to work under him, notably creating several longitude clocks and watches, such as the present piece.