RARE 46MM EXPERIMENTAL BALANCE JULES JURGENSEN POCKET WATCH 20J MOVEMENT ONLY. RUNNING STRONG WHEN WOUND NOT TIMED OR CHECKED FOR TIME. DIAL IS SIGNED JULES JURGENSEN COPENHAGUE AND HAS NO LINES CHIPS OR CRACKS AN EXCELLENT DIAL AND ORIGINAL GOLD HANDS.Precision pocket watch by Jules Jurgensen with counterpoised lever escapement, experimental. Unusual, cut bimetallic balance with rim made up of alternating prismatic sections of brass and steel resembling a saw blade. And large gold timing screws. This is a very unusual movement and dial. The dial is stamped on back Ohara Dial Co Waltham Mass and also is scratched into the enamel the serial number 10430-- which is the serial number on the front plate.
The serial number on the back plate is engraved 14532 and the balance arm has no serial number scratched on the bottom of the crossarm and the balance cock has no serial number stamped into the bottom. My guess is as good as yours so guess away. This watch movement is from an estate of a watch collector and no more information is forthcoming but the actual piece itself.
Open face silver case 20 jewel watch with same counterpoised lever escapement and balance. This may have been an experiment by Jules Jurgensen using his patent balance (1827- 1899). Theodore studied watchmaking under Simon Vissiere, and later worked for both Winnerl and Breguet. He was a very skilled watch and chronometer maker, and was appointed "Horloger de la Marine" in 1859, the same year in which his son, the celebrated Louis Leroy was born. It is interesting to note the similarity between the balance in this watch, and the patent balance of Charles Vander Woerd.
While the Woerd balance patent specifies that the prismatic laminae are to be approximately one sixth of the circumference of the balance diameter, with the bimetallic portion located at the fixed ends of the rim, the Leroy balance uses the prismatic laminae for the full length of the rim. The "Reports of the United States Commissioners to the Paris Universal Exposition 1878" discuss Woerds new balance on pages 412- 414, and may have influenced Leroy to experiment with the design. The item "46MM RARE EXPERIMENTAL BALANCE JULES JURGENSEN POCKET WATCH 20J MOVEMENT RUNS" is in sale since Wednesday, March 18, 2020.
This item is in the category "Jewelry & Watches\Watches, Parts & Accessories\Parts, Tools & Guides\Parts\Movements". The seller is "partimeart" and is located in tampa, FL. This item can be shipped worldwide.