Important Collectors’ Wristwatches, P...

Hong Kong,the Ritz Carlton Hotel,harbour Room, 3rd Floor, Nov 25, 2006

LOT 15

?Special Patented Power Source? Isaac Grasset & Cie, Geneva. Made circa 1898. Interesting and rare, silver and gold, keyless pocket watch with special patented power source.

C. Three-body, "bassine et filet", engine-turned back with polished gold border and bezel, vacant cartouche. Glazed silver-rimmed cuvette. D. White enamel, Arabic numerals, outer minute track with five-minute Arabic numerals, subsidiary seconds. Blued steel, "spade" hands. M. 43 mm. (19'''), Grasset bridge caliber, 15 jewels, straight-line lever escapement, cut bimetallic compensation balance, blued steel Breguet balance spring, power source in the form of a narrow coiled spring wound around the winding stem which terminates with a contrate gear meshing with the center wheel pinion. Movement signed. Diam. 50 mm.