Important Collectors’ Wristwatches, P...

Geneva, Mandarin Oriental Hotel Du Rhône, Oct 15, 2006

LOT 403

"One-Minute Tourbillon Early Keyless Winding" Jules Jürgensen, Copenhagen, No. 8603. Made circa 1855. Very fine, extremely rare and important, large, 18K gold pocket detent chronometer with one-minute tourbillon regulator, experimental early keyless winding and Réaumur thermometer with Fahrenheit and Centigrade scales.

CHF 140,000 - 160,000

EUR 90,000 - 100,000 / USD 115,000 - 130,000

C. Four-body, "bassine et filets", engine turned and polished, reeded band. Hinged gold cuvette. D. White enamel with narrow radial Roman numerals, outer minute track, large subsidiary seconds at 6, Réaumur thermometer scale in the upper half of the dial with scales for heat and cold, calibrated from -15 to +55, Centigrade scale from -20 to +45, and Fahrenheit from -10 to +120. Blued steel Breguet hands. M. 47 mm., (21???), bar caliber, frosted gilt, steel winding wheel fitted above the going barrel and the intermediate winding wheel fitted on to the central bar plate, polished steel one-minute Henchoztype tourbillon carriage with three equidistant arms, foliate engraved brass rim, Earnshaw's spring detent escapement, cut bimetallic compensation balance, blued steel Breguet balance spring, index regulator arm on the carriage. Dial, movement and case signed. Diam. 56 mm.


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Grading System
Grade:
Case: 3-15

Good

Slightly rusted
Movement: 3*

Good

Overhaul recommended, at buyer's expense
Dial: 3-01

Good

HANDS Original

Notes

Tourbillon watches by the Jürgensens are extremely rare; we know of only three completed ones. The present watch is No. 8603; the second one is No. 9557; the third No. 14168. All three have detent escapements. The present watch has been fitted with an early form of keyless winding, almost certainly whilst it was still in the Jürgensen workshop. The type of early winding with separate hand setting used in this watch is consistent with a date around the early 1850s and from the Jürgensen workbooks the number of this watch falls between 1853 and 1857. This is a very interesting addition to the predecessors of the modern stem-winding system and stands alongside those systems patented by Audemars, LeCoultre, Adolphe Nicole and Adrien Philippe in the 1840s. The system exhibited on the present watch has some similarities to the one Adolphe Nicole patented in 1844 with the exception that the hand-setting lever is in the bezel. The Réaumur thermometer is sometimes encountered on the watches of Jules Jürgensen and also his father Urban. They used the system invented by Jacques Frederic Houriet, whereby a "U" shaped bimetallic strip activates a spiral hairspring connected to the thermometer hand.

René Antoine Ferchault de Réaumur (1683 - 1757)
Born in La Rochelle, René Antoine Ferchault de Réaumur pursued his studies first in his native city, and then in Poitiers and in Bourges. After studying law, he turned to mathematics, which he studied in Paris beginning in 1703. The publication of his ?Memoirs in Geometry? brought him to the attention of the Académie des sciences. Réaumur joined the Académie when he was only twenty-five and became director of the publication "Description des divers arts et métiers". Réaumur studied many things, including the ductility of metals, the resistance of cables, and the magnetism of iron. His research into iron alloys is particularly important and was presented in "l'Art de convertir le fer forgé en acier et l'art d'adoucir le fer fondu" in 1722. This research led to the introduction of steel in France. Réaumur studied the composition of metals under a microscope, thus founding the study of metallography. In 1730, he constructed the first alcohol thermometer, for which he designed a scale from 0 to 80 and whose indications allow for comparison. Réaumur also made important contributions to the natural sciences, being particularly interested in the study of invertebrates. A similar watch is published in ?Le Tourbillon? by Reinhard Meis, p. 196-197