Swiss minute repeating split seconds chronograph Circa 1880

Rose gold open faced repeating split seconds lever chronograph
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A very fine, rare Swiss 18 carat rose gold open faced minute repeating keyless split seconds chronograph lever pocket watch made for the American market, circa 1880. Rhodium plated, 32 jewels, counterpoised straight-line lever escapement, cut bimetallic compensation balance, blued steel Breguet balance spring, index regulator, repeating on gongs activated by a slide on the band, visible chronograph work. Hinged gold rimmed glazed cuvette to view the movement. Silver regulator type dial, small dial at 12 with Roman numerals for the hours, outer minute track with red champlevé enamel five minute numerals, subsidiary seconds at 6 and original blued steel double spade hands.  Polished case, bolt at 1 o’clock to lock the chronograph.
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Diameter: 52 mm
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Signed: No name
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A split seconds chronograph, or ‘rattrapante’, is a type of chronograph watch with two coaxial superimposed centre seconds hands that are controlled by two push buttons. One push button controls the split seconds hand to stop or join the chronograph hand. The other push buttons control both hands and all the chronograph functions. The chronograph and split seconds hands are used for timing several events that start simultaneously, but are of different durations. To operate the split seconds chronograph, both hands are started and remain superimposed. Then at the end of the first duration, the split seconds hand can be stopped while the chronograph hand continues to move. The duration of the first event can be read. After recording, the split seconds hand can be released to instantly move and join the chronograph hand, synchronizing with it and thus being ready for another recording. At the end of each event the hands then can be stopped and returned to zero. The split seconds chronograph, in its present form, was first introduced in 1880. Split seconds chronograph wristwatches came on the market circa 1922 by Patek Philippe (the first known wristwatch of this kind was Patek Philippe No. 124824, case No. 235326. This timepiece appeared five years prior to the official release of the split seconds chronograph, making Patek Philippe the first manufacture to create this complication in a wristwatch. As they require a highly complicated and technical mechanism, these watches are desirable, very collectible and extremely difficult to produce accounting for their rarity.