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Auktionen Dr. Crott 88. Auktion

THE PERFECT MARINE BALANCE OF THIS CLOCK AND THE ESCAPEMENT The balance or, rather, a foliot is placed in the back of the escapement mechanism. It consists of two cylindrical weights placed on threaded ends of the foliot ends. In the middle there is a short brass pendulum swinging between curved cheeks11 with a ribbon suspension. At the top there is a nut for adjusting the apparatus. The escape wheel has two wheels, each of 15 teeth. The smaller one gives impulse directly to the balance via a large pallet placed on the balance arbor, the same as in a chronometer or duplex escapement. The large wheel is for locking. Huygens needed to find a place for the pendulum. Outside the plate was not possible due to the balance (foliot). Therefore, he caged the 4 wheel and the seconds wheels, which gave him enough space for the pendulum between the plates. There are two sets of anti-friction rollers (disc bearings), two large ones in the back and two small ones in the front. The case is based on a rectangular frame, almost exactly as in a Huygens drawing of his pendulum clock12 . All observations support dating BMP2 to the 1680s. Quoting Jean-Dominique Augarde,13 “until the end of the eighteenth century, the great cabinet-makers who were responsible for the glory and the fame of France in this domain were not native born, … most distingu- ished came directly from the countries situated within the ancient bound- aries of the German Holy Roman Empire, especially from the Rhineland, the Dutch provinces, and Flanders“. Some of the artists must have stayed in the Dutch provinces: Huygens would not have had a problem finding one. The mask of Apollo within sunrays at the top of the clock is typical for the period and many similar ones can be found such as a Louis XIV decoration from a panel in the Louvre. It represents the Sun God to whom Louis XIV likened himself The central sunburst pattern also alludes to Louis XIV, the Sun King. THE SECRET LOCKING OF THE CASE The clocks case is constructed in such a way that, unless one is quite familiar with it, it is impossible to see anything inside or even quickly take it apart. Even if one figures out the role of two small pin holes which let the front panel open, one needs a screwdriver and a good half an hour to get to the movement. This is entirely consistent with the research of the two foremost Huygens experts: John Leopold and Prof. Michael Mahoney. In addition to Leopolds statement, Huygens work in establishing longitude by timepieces was a matter of some secrecy, Mahoney joins him with “… Huygens jealously guarded the fortune that might result from his inven- tions“.14 The maintaining power is of the bolt and shutter form acting on the center wheel. It is one of earliest designs known. Few clocks by Fromanteel from 1665-70 are known with a similar arrangement.15 THE EQUATION OF TIME Since this is the earliest surviving clock with equation of time, it deserves detailed description. The first known equation of time clock was built by John Fromanteel to the specifications of Nicholas Mercator, who showed it to the Royal Society in 1666 and then presented it to the king. In France, Pierre Gaudron claimed that his father built one in 1688, which was the first in France. These have not survived, or if they have, their whereabouts are unknown. This clock is from the same period and has survived. The equation is based on an annual calendar wheel which is driven by a worm mechanism starting from an endless screw driven directly from the hour wheel, which has a worm gear milled on its thick sleeve. This is inherited from not much earlier Renaissance mechanisms. CONCLUSION The clock is one of those rare, important objects from the past that has changed our understanding of the history of the technology. Many of them have been lost forever. This one was in front of our eyes from the 1980s but wrongly attributed. We now know that it is Huygens Balancier Marin Parfait, the oldest longitude clock in existence, the inspiration for Harrisons prize-winning longitude clock, and the oldest surviving equation of time clock. While Huygens premature death prevented him from finding the ultimate solution for longitude, he came very close to this discovery. Eventually, it was captured by John Harrison (who, coincidently, was born the year Huygens died) who found the answer in metallurgy (bimetallic compensation), but it was Huygensoriginal work that guided Harrison through the mechanics.16 These mechanics achieved their pinnacle in this newly discovered Huygens clock, the BMP2, the last one he ever built, partially with his own hands,17 the one to which he applied his lifetime of experience, and which eventually was to lead to the solution of the longitude problem. 1 W. S. Laycock in The Lost Science of John “Longitude” Harrison (1976) stated: “…the Englishman [Harrison] owed far more to his Dutch prede- cessor than he either knew or would admit“. 2 The Proceedings of the Longitude Symposium (Cambridge: Harvard University, November 4-6, 1993), p. 112. 3 Oeuvres Complètes de Christiaan Huygens (farther O.C.), vol. 10, No. 2891, pp. 709. 4 And later by C.A. Crommelin, published in Les horloges de Chris- tiaan Huygens, Bulletin No. 61 of the Musée National d’Histoire des Sciences, Leiden. 5 Thanks to Patricia H. Atwood for this information. 6 See note 3. 7 O.C., vol. 18, pp. 571-91. 8 Huygens letter to Alexander Rolas de Roisey, the Chamberlain to the Prince. O.C., vol. 10, no 2878, pp. 684-5  9 O.C., vol. 18, p. 572  10 O.C., vol. 18, p. 576  11 Following his 1693 discovery of involutes of circles, Huygens specifically described the suspension cheeks as involutes of circles, not cycloids. 12 Christiaan Huygens, Horologium Oscillatorium, 1673. 13 Jean-Dominique Augarde, Les ouvriers du temps, Geneva, 1996. 14 J. H. Leopold, The Longitude Timekeepers of Christiaan Huygens, The Longitude Symposium, Harvard University, 1993. Michael S. Mahoney, Christian Huygens: The Measurement of Time and of Longitude at Sea, in Studies on Christiaan Huygens, ed. H.J.M. Bos et al. (Lisse: Swets, 1980), pp. 234-270. 15 Longcase clock ca 1670 in the G. Marsh Collection, Winchester, England; table clock in the Prestige Collection; longcase clock ca 1665 in the British Museum (inv. CAI-2099). 16 W. S. Laycock, The Lost Science of John Longitude Harrison (Ashford, Kent, 1976). 17 Judged by the fact that Huygens worked on previous clocks himself; in 1683 he made a model for his torsion pendulum. For his first Perfect Marine Balance, he made a balance himself and experimented with different types of chains. O.C., vol. 18, pp. 546-561 and 592-96. 傳奇性,極富歷史價值的經度儀壁鐘,附完美擺輪”BMP2” 37819  G/C: 2 Z/D: 2 W/M: 2, 17, 41  600.000 - 1.000.000 EUR 810.000 - 1.350.000 USD 6.600.000 - 11.000.000 HKD Eine umfangreiche Dokumentation mit detailliertem Bildmaterial finden sie auf unserer Homepage unter News. For an extensive documentation with detailed visual material visit our homepage, under the news section.

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