Girard-Perregaux celebrates its 225th anniversary this year with several new watches, the star of which is La Esmeralda Tourbillon. As is the tradition with heritage brands, which tend to accumulate large archives and collect historic pieces for brand museums, Girard-Perregaux based the La Esmeralda on an archival piece, a pocketwatch with a chronometer-rated Three Bridges tourbillon movement (pictured below). The original La Esmeralda, with pivoted detent, tourbillon escapement and three gold bridges, won a gold medal at the Universal Exhibition in Paris in 1889. The case was engraved by renowned artist Fritz Kundert, who at the time was at the pinnacle of his career. The one-of-a-kind piece was named La Esmeralda after the Paris and Mexico boutiques of Hauser, Zivy & Cie, a jeweler and watch merchant. The watch was owned by General Porfirio Diaz, then President of Mexico. Girard-Perregaux acquired the piece for its museum in 1970.
Although the new Esmeralda is not a pocketwatch, the case was constructed to imitate the multi-layered original, which was hinged with front and back case covers, plus a second, hunter-style cover protecting the bridges. The case of the new La Esmeralda, in 18k pink gold, is an aesthetic nod to the original, with a rounded bezel ring and a caseback ring slightly overlapping the middle case band to evoke the layered, covered look of the original. It measures 44 mm in diameter and houses the automatic Caliber GP09400, with a 14.3-mm-diameter tourbillon carriage and a 10.5-mm-diameter balance wheel. The unique automatic winding system uses a rotor that is positioned concentrically under the barrel — a larger one than in the original, thus housing a longer mainspring — giving the piece a power reserve of at least 60 hours. (The archival Esmeralda had a 48-hour power reserve.) Like its historical predecessor, the new piece has five screws on each bridge, whereas more contemporary three-bridge tourbillons contain only one. The surfaces of the arrows are mirror-polished, the edges are chamfered by hand, the flanks are drawn and, to better catch the light, the arms of the bridges are carefully rounded by hand using a burnisher. La Esmeralda is water-resistant to 30 meters and will be produced in limited quantities.
Girard-Perregaux’s Tourbillon with Three Bridges caliber is the oldest watch movement still in production, since its overall layout has remained unchanged since its introduction in 1860. The three bridges include a barrel bridge, gear-train bridge and tourbillon bridge, all made from solid gold. Twenty-seven versions of the movement were registered with the Neuchâtel Observatory by Girard-Perregaux from 1865 to 1911.