Several elements suggest that this watch was a unique prototype: the 12?? movement (2.255 mm smaller than the usual 13??? one); the fact that the watch is flatter by 1 1/2 mm; and that the chronograph bridge is not engraved in the usual manner. The signature is engraved on the movement, as is stated in the Extract from the Archives. A similar watch is published in ?Collecting Patek Philippe Wristwatches? by Osvaldo Patrizzi, Guido Mondani Editore, 2004, vol. II, pp. 49 & 50. Ref. 130 Production of this reference started in 1934, being made in stainless steel, Staybrite, yellow gold, pink gold, stainless steel and gold, and only three in white gold. It is one of the most desirable and sought-after sport watches ever created by the Patek Philippe firm. Sophisticated collectors appreciate this model's perfect proportions, its large and clearly-read dial, encircled by a slender, concave bezel which gives the dial an even greater luminosity. It is very rare to find a chronograph with a single button; Ref. 130 usually has one button at 2 and another at 4. Only a very few examples were made with a single button on the crown. This reference was first used with Victorin Piguet ebauches, and later with Valjoux ebauches. Two examples of the Ref. 130 single button chronograph are known to exist; one was sold by Antiquorum: Exceptional Horological Works of Art, Geneva, 19 October 2002, Lot 74. The present watch is the only known example of a Ref. 130 single-button chronograph to feature an experimental 12''' movement. This watch was recently completely overhauled by Patek Philippe, including its case and dial. Patek Philippe single-button chronograph wristwatches are technically and esthetically remarkable, both in terms of iconography and the conception of the movement. The present watch, with the simplicity and clarity of its dial, is a particularly impressive example. The register dials, tachometer grad-uation and outer 1/5th second scale are arranged on the dial with perfect elegance. This, associated to the pure lines of the case, creates an especially satisfying impression of geometrical harmony, an example of the best in Art Deco design.