百達翡麗

• 手動上弦鍍鎳機芯21'''，棘爪計時擒縱機構，30顆寶石，雙金屬補償擺輪，藍鋼螺旋游絲，游絲，雙錘雙簧 • 白色琺瑯錶盤，寶璣式數字，小錶盤連秒速顯示，外環分鐘刻度，藍色梨形指針 • 18K黃金亮面錶殼，揭蓋式藍寶石水晶背透蓋，錶側設打問滑桿 • 錶殼、錶盤及機芯印有品牌標誌

* 拍品資料以英文圖錄為準。

From the family of the original owner 

Please note that the movement has not been checked for timekeeping accuracy and Sotheby's will not be held responsible for any repairs should they be required. The movement and the striking mechanism are running at the time of cataloguing. Dial in very good condition case with few scratches due to use and age. Very nice example.
"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.

Important Notice regarding importation into the United States of Rolex watches
Sotheby's cannot arrange for the delivery of Rolex watches to the United States because U.S. laws restricts the import of Rolex watches. The buyer or a designated agent may collect the property in the country of sale."

THE DETENT ESCAPEMENT AT PATEK PHILIPPE

During the final 20 years of the twentieth century, Patek Philippe started to case and complete a small number of movements with detent escapements (numbers 866’xxx). This extremely limited production appears to have consisted of no more than 2 movements every 3 years.

At the present time, only 33 Patek Philippe movements with detent escapement are known to the market, and according to our research there
are:

• between 7 and 8 movements that have never been cased

• 5 movements that are known to incorporate quarter
repetition 

• between 2 and 3 with minute repeaters (present lot and see
also lot 170, Sotheby’s Geneva, 12^th November 2013) and between 9
and 12 movements starting with the number 866’xxx     

• 3 deck marine chronometers

• 2 detent escapement movements with tourbillon

The complexity and skill required to produce the detent escapement has resulted in historically low production numbers. It is interesting to note that, by comparison, 93 tourbillon movements are known to have been cased as pocket watches by Patek Philippe, three times the number of detent movements known.

THE CHRONOMETER

It is to Pierre Le Roy, son of the famous French watchmaker
Julien Le Roy, that we owe thanks for the three fundamental principles that led
to the development of the modern chronometer timepieces:

1. the free escapement

2. the self-regulating balance

3. the isochronous hairspring

Comparing the construction of the free escapement introduced
by Pierre Le Roy, represented in his ‘Works’ in 1748, published in the History
of the Academy of Sciences and applied in 1763, one can see how this device differs from its earlier version. The innovations capture the huge amount of effort which Le Roy deployed during this long period in order to achieve both principles with the free escapement and conditions of isochronous oscillations linked to the adjustment of temperature compensation.
In his “Précis des recherches ...”, Pierre Le Roy mentioned, in 1768, a work
that he had already announced in 1750, called “Essai de physique et de
dynamique sur les ressorts des corps”, which was never published. The
manuscript of this essay shows that, from this period, his researches on
friction, the elasticity of springs and the phenomena of metal dilatation had
led him to conceive a primitive form of equalizing winder and a mechanism to
compensate the effects of temperature on the functioning of watches. Pierre Le Roy presented many papers to the Academy, concerning both watches and clocks. However, his work in the field of marine clock making is so important that it possible to speak of him as a true genius. In 1748 he conceived a detent escapement whose design, published by Gallon in “Machines et inventions approuvées par l’Académie Royale des Sciences”, does not entirely explain its way of functioning. It does, however, show the first attempt at making an escapement which ensured that the balance would have complete freedom of motion, outside the phases of unlocking and impulse. The successful design of the escapement, which enabled the vibrations of the balance all the freedom and necessary regularity, allowed Pierre Le Roy to realize that in any spiral spring of sufficient stretch, there was a certain length in which all vibrations are isochronous. This meant that the oscillations, large or small, could be fulfilled in the same period of time. Consequently, this finding led Pierre Le Roy to vary the length of the spiral setting to compensate for temperature variations. It was mandatory that the compensation be made directly on the balance itself. He therefore devised a circular cut bi-metallic balance, in which the segments were distorted inward or outward, due to the difference in coefficient from the thermal expansion of its components, thus compensating for temperature variations. In England, based on Le Roy’s principles, John Arnold, followed by Thomas Earnshaw, produced the very first truly operational marine chronometer watches, which equipped the ships of the British Navy. On the continent, it was Louis Berthoud who was the first, along with his nephew and pupil, Henri Motel,
who also built on these principles, the chronometer watches which equipped the French Navy. Thereafter, the pivoted detent escapement allowed the development of this device in almost all important chronometer watches.