On May 9, 1792, Louis Berthoud deposited a sealed document at the French Académie des Sciences. The document was lost during the Revolution and was only rediscovered in 1977, at which time it was opened and read by the president of the Académie. It revealed Berthoud’s concepts of precision watchmaking, revolutionary for the time. Previously, French precision timekeepers, made by such pioneers as Pierre Le Roy and Ferdinand Berthoud, had been bulky and fragile instruments. Seeing their disadvantages, Louis Berthoud devised a new portable precision Marine Watch. When Berthoud finished work on a watch for his uncle Ferdinand Berthoud (see previous lot), he devoted all his efforts to developing a portable precision timekeeper. His thoughts were written down in the sealed packet deposited with the French Academy of Sciences; his ideas were implemented in this very watch. Reading the document he deposited at the Academie, it becomes obvious how much research, effort and experimentation went into this project, whose aim was, after all, to profoundly change French precision horology: "I should explain principles that I have used until now, show the reasons that led me to change them… Considering the essential basis for accuracy in a watch, that is constancy and the reduction of friction, the isochronism of its beats and compensation for heat and cold…In the seven years that I have devoted to this end, I have used virtually every metal to make the pivot holes, whether in pure gold, gold combined with copper, silver… Finally, these last two years I have used platinum. I think that I have to abandon this metal too. I believe that it is absolutely indispensable for watches of which the accuracy has to be assured for 3 to 4 years, to use the most reliable means, either very carefully pierced and polished rubies or friction rollers….I have observed in repeated expe-riments that pivots of 3/48 ligne, running in rubies can not carry a balance of more than 15 to 18 grains without being subject to wear. This weight of balance is not sufficient for a regulator... moreover oil is needed with rubies as with metals. It was these considerations that let me to run the balance of the watch that I constructed in 1787 for Monsieur de Chastenay Puységur between very light rollers having very fine pivots. I think that I can assure myself that it is the first of this kind and of so small a size. It has only 24 lignes, each of the rollers is equal in diameter to the radius of the balance. The three are held in the frame between a cock set on the top plate and three bridges. I extended the balance arbor almost up to the dial and instead of rollers, put a ruby…" It should be noted that Louis Berthoud was the first French watchmaker to use pierced jewels for his watches. The present watch is the first that he made after working for his uncle Ferdinand, and while working for his uncle he made no jeweled watches; this is therefore the earliest French jeweled watch, even if its jewels consist of only one ruby and one diamond endstone. It was the first of many French jeweled timepieces: Louis Berthoud continued to use them, and Ferdinand Berthoud followed suit as did Breguet and Lépine. But the beginning was here, in this very watch. The other side of the balance is fitted with friction rollers – the first such arrangement in the world in a portable timepiece. Friction rollers had been used before, but in large clocks, the first by Sully. Berthoud continues: "…Another way of reducing friction to which I applied myself concerns the teeth and meshing, whether between pinions or the wheels. Ordinary manufacturing does not give us anything but 10 or 8 (pinion) leaves. I constructed several machines in which I made the same pinions with 16, 18, or even 20 leaves. Making them becomes infinitely longer and more difficult, but the precision of the gears, and the equalizing the pressure on the arbors, amply repays the trouble. I draw here only the essential pieces and the detent just as I made it for M. Puységur’s watch. … It weighs less than half a grain. The return spring is very weak and its thickness at the bottom is only 1/96 of a ligne. … I have made some with inclination reaching 80o, but detent becoming much heavier, I had to abandon it… I turn now to the compensation….The first that I thought of were formed of a simple strip of brass and steel riveted together…but I soon recognized the imper-fection of this method. ...In 1785 I devised the following composed of three arms and a steel band to which I riveted a second band of brass, each of them cut close to the arms. …It was still necessary to add the weights and make them adjustable. To this end I made brass band with a suitable slot to hold the ring of the compound balance, leaving as much outside as inside and above. …The care that these balances require is in-finite and I must say that it is incredible that they keep their equilibrium so well as they pass through different tempe-ratures... …That of Monsieur de Puységur’s watch was the fourth of this kind….Coming to the details of the balance spring, subject no less important than the preceding. … The first that I have made had eight or ten coils, the steel hardened by rollers and not by dousing…. But they did not allow for a very large arc as the coils knocked against each other... I decided to make springs in a form of a helix. …While acquiring greater experience in making them I won the advantage of hardening them already formed. The first that I used is that in the watch of M. de Puységur. These balance springs seem to me in every respect preferable to others…I experi-mented with gold, silver and laminated brass to make my balance springs and I admit that I could not imagine what can be the advantage over steel." Berthoud continues to describe his adventures in creating the basis for French precision por-table horology, clearly a very long, tedious, and frustrating process; the results, however, were remarkable. When the watch was ready, Ber-thoud sent it to the Director of the Paris Royal Observatory, Comte Cas-sini. Cassini had the watch tested by Monsieur Nouët for positions, and most importantly for temperature. The trial lasted 18 months. The results exceeded all expectations and Berthoud was honored with the most prestigious National Award and 6000 livres. The report by Monsieur Nouët of the Royal Observatory to the Académie Royale des Sciences on May 12, 1790 states among other things: "…Mr. Berthoud’s watch was already made at the time of the voyage that Monsieur de Chastenet had to make in the Mediter-ranean. He was even able to study its going at the Observatory of Malta. …Monsieur de Chastenet consigned the watch to me to observe its going at the Royal Observatory. I have compared it since the 28 January, 1789 up to now, with an excellent clock constructed by Monsieur Berthoud, the uncle, which we have often had occasion to check either with the sun, or with a large number of stars. During 19 days I kept the watch in an temperature of 9° with a variation of only 2°….Its greatest variation was 1"9… I placed it for 8 days in a hot box where day and night I maintained constant temperature of 25°, …its greatest variation 1"4…." He continues giving the details of its going for the next nine months. After that he summarizes the results: "…For how many centuries has humanity tried to trace a reliable route on the vast ocean… Astronomy was our first guide… It seems that this watch, which I have the honor to present to the Académie with such satisfying results, can compete with Astronomy since it offers, by its performance, such great precision for long voyages. Monsieur Berthoud the younger has thus rendered an important service to the marine…I feel obliged to render him this homage before the Académie whose approbation is the most worthy recompense of his talents…" Cassini followed the report with his own in which he also highly praised the watch and added: "…These results greatly honor the talents of M. Berthoud. We think that in applauding his success, the Académie will encourage him to redouble his efforts to merit further approbation. Our hope is the better grounded in that this able artist concerns himself particularly with the perfection of the pocket watches…" The commissioners of the Bureau of Consultation wrote a report stating: "…Monsieur Berthoud merits the maximum in the first class of national awards, of a value of 6000 livres, and considering the great importance of the object, in addition with the epithet ‘honorable’…" Paris, this 19 August 1792, fourth year of liberty, and the first of equality. In 1793, this watch was considered so important that the Academy’s organ Lycée des Arts, reported on May 5: "France is indebted to several very knowledgeable men who should be congratulated and encouraged. Among them one has to be especially encouraged. His high reputation does leaves no doubt about whom we are speaking – Louis Berthoud. Several years ago he made a Montre à Longitude, the precision of which was so great that it surpassed all that had been made at the time. Its rate was as good as the excellent clock from the Observatory of Paris of which we have already spoken. Jean Baptiste LeRoy and Berny." In 1809, at the Exposition de L’An X, Berthoud received a gold medal. The Commission in its report stated : "…The first of these efforts is a small marine pocket watch which Monsieur Chastenay de Puységur ordered from him. It was made in 1786 and turned over to M. Cassini, Director of the Observatory for testing. The trials were made for 18 months in all degrees of temperature and it was recognized to be just as accurate as the best watches coming from abroad…." At some point before delivering the watch to von Humboldt Berthoud decided to replace the mainspring for a stronger one. In his journal in February, 1795 he wrote: "…concerning the watch Puységur, in the beginning it had a smaller and shorter barrel." Most likely it is the same change which was mentioned in an earlier report of Monsieur Nouët of the Royal Observsatory, dated January 1787: …On his return to Paris, Monsieur Berthoud wished to add a piece to his watch. This addition was the result of his new observation…" The watch performed equally well for its next owner, the celebrated physicist and naturalist, Alexander von Humboldt. On December 10, 1798, Von Humboldt, soon after having bought the watch wrote to Berthoud to express his satisfaction: "…this delay made me realize how much I owe you. I have been able to observe the going of my chronometer in relation to the movement of the stars, and citizen Thuilier was astonished, as was I, by the beauty of your work. Despite the fact that this chronometer suffered the most horrible shaking in the diligence from Paris to Marseille (above all near Avignon), a shaking that damaged my lovely English theodolite, I was yet able to give the longitude of Marseille to Citizen Thuillier to within 9"4…" During the trip to Marseille von Humboldt took notes regarding the rate of the watch. The average error was 1"5. He continued: "This recognized, the maximum error should only be 0"7, a very small amount, that the best of Emery’s chronometers do not attain, their minimum error being as much as 1"5. From 27 Brumaire to 7 Frimaire a great shaking that I gave to the chronometer was the cause of its going slowly…. …I hope that this report will give you the same satisfaction as it has me. If you see our respected Monsieur Borda, express to him my gratitude for the happy advice that he gave me to acquire this superb chronometer". Literature: J.-C. Sabrier, "La Longitude en mer à l’heure de Louis Berthoud et de Henri Motel", Antiquorum Editions, Geneva, 1993, pp. 49, 61,83-10, 179, 180, 224, 230, 231, 245, 267, 288, 294, 322-325, 430-431. Baron Alexander von Humboldt (1769-1859) Physicist and naturalist, born in Berlin, the brother of diplomat and philologist Wilhelm von Humboldt. Alexander was a great traveler who explored the American continent along with Aimé Bonpland, journeying through the equatorial regions from 1799-1804. France was his second country; upon arriving in Paris in 1805, he was admitted as an associate member of the Académie des Sciences. Among his friends were the most eminent savants of the capital, such as Arago, Gay-Lussac, Cuvier, Latreille, and Achille Valenciennes. His sovereign recalling him to Berlin in 1827 to fill the role of Privy Counselor, it was in this capacity that he officially recognized the new king of France following the July revolution. At the request of Czar Nicholas I of Russia, Humboldt undertook a second Asian journey, of which an account was published in 1838 as "Fragments de géologie et de climatologie asiatique", which made important contributions to these disciplines. His most important work is "Kosmos, ou description physique du monde". Humboldt did significant work in what today are the sciences of climatology, oceanography, biogeography, geology, volcanology, and geomagnetism.