A gold openface chronograph watch with register and pulsemeter, Ulysse Nardin, Locle & Genève, circa 1915

18k, nickel lever movement, bi-metallic compensation balance, micrometer regulator, gold cuvette, white enamel dial, Breguet numerals, two subsidiary dials indicating constant seconds and 30 minute register, outer ring calibrated for pulsations, case, cuvette, dial and movement signed.