Swiss stainless steel open faced chronograph Circa 1950

Steel open faced keyless lever chronograph
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A rare Swiss stainless steel Extrafort pocket chronograph watch made by Eberhard & Co. in La Chaux-de-Fonds, circa 1950. It has a mechanical 16”’ calibre crown winding movement with a lever chronograph mechanism and Extrafort slide button, and is signed Eberhard & Co. The original galvanic black dial features radium luminous Arabic numerals and vertical sub dials showing constant seconds at 6 o’clock and a 30 minute recorder at 12 o’clock. It also has inner telemeter and outer tachymeter scales, a central chronograph hand, and luminous pencil hands, signed Eberhard & Co. The timepiece is housed in a large stainless steel open faced case with a plain polished finish. It has a slide push piece at 2 o’clock to lock or unlock the chronograph function, a flat top suspension bow, a fluted winding crown, and a snap on back cover.
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Diameter: 56 mm
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Signed: Eberhard & Co. La Chaux-de-Fonds
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Eberhard & Co.
Founded in 1887 in La Chaux-de-Fonds by Georges-Lucien Eberhard, Eberhard & Co. established itself as a premier Swiss watchmaker known for technical innovation and precision chronographs. Over the decades, the independent brand introduced landmark creations including early wrist chronographs, the secure Extra fort line, the Scafograf diver’s watch, the 8 day power reserve 8 Jours, and the revolutionary Chrono 4 with four horizontally aligned sub dials.
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Extra fort
In the 1930s, Eberhard & Co. introduced the Extra fort chronograph mechanism, which featured an innovative slide button designed to lock and protect the chronograph function against accidental resetting or damage. Thanks to its remarkable success and enhanced security, the Extra fort became one of the brand’s most iconic and enduring model lines for both pocket watches and wristwatches.