French chronograph with tachy- and pulsometer scales Circa 1920

Gold keyless chronograph attributed to Louis G. Tribaudeau
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A fine French 18 carat gold open faced keyless chronograph pocket watch, circa 1920. This watch features a 1/5 second chronograph activated through the winding crown, telemetric scale graduated for 6 kilometres, pulsometer scale graduated for 30 pulsations and a half instantaneous 30 minute counter. The polished case with a taille douce engraved back and the monogram SL, the pendant is based on Swiss patent No. 4 646 delivered to Louis G. Tribaudeau in Besançon, France, on February 15th, 1892, for a pendant perfectionné pour montres de tous genres (pendant perfected for watches of all kinds). White enamel dial with bold Arabic hours, an outer minute and fifth of a second track with five minute numerals, subsidiary seconds at 6 o’clock, a 30 minute counter at 12, tachymeter and pulsometer scales and gold spade hands. The gilded brass movement with a straight line lever escapement, going barrel, compensated balance and palladium hairspring with a terminal curve.
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Diameter: 53 mm
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Signed: No name