Jaeger-LeCoultre

Regarding the movement, the Duomètre chronograph is fitted with a Jaeger-LeCoultre Caliber 380, whose major advantage is that it displays the time with the precision of a chronometer. To my knowledge, this is the first movement that used this new construction principle. Thanks to the Dual-Wing concept, a first gear train is entirely dedicated to the time function (hours, minutes, seconds), the second gear train is dedicated exclusively to the chronograph function, with a lightning second to 1 / 6th of a second . Each of the two mechanisms is powered by its own barrel providing a 50-hour power reserve (50 hours for the hour, 50 hours for the chronograph). No energy transfer takes place on either side. To simplify use and perhaps also to ensure the aesthetics of the watch, a single crown is used to wind the two barrels: it is thus necessary to turn the crown clockwise to wind the time and turn it anti-clockwise to ensure the winding of the chronograph. Unlike most watches, it is therefore necessary to make a movement in one direction and then a movement in the other direction to wind the two barrels equally. Unless I am mistaken, the Duomètre chronograph with its Caliber 380 was the very first wrist watch chronograph to operate without having to resort to a clutch to ensure the functions of starting and stopping time measurement: One and only one pusher ensures perfect synchronization of the five chronograph counters.

Beyond its operation, the aesthetics of Caliber 380 have been meticulous. The independent barrels are snailed and bevelled by hand, the ratchets are sunray with the engraved and gilded “chronograph” and “hour minutes” indications. The bridges, made in nickel silver (maillechort), reflect the Dual-Wing concept, with taut and straight shapes for the hour mechanism, and arabesques for the chronograph, revealing the hearts, hammers, jumpers, the column wheel and mechanism wheels. This decoration, which I find particularly successful, seems to be inspired by the brand's pocket watches. We can also note that the cogs have a circular satin finish and polished moldings. The mobiles, also bevelled or adorned with polished moldings, are snailed or softened. Finally, the flame-blued steel screws underline the complexity of the caliber. Another little trick that I find cool is that the main lines of the bridges point to the single regulator.

In short, from my point of view it is beautiful and efficient. This watch has a rather rare form of poetry.

I can add that this is a limited series of 200 copies, but that's almost a shame given the appeal I find in this piece.

It is of course full set, with its magnifying glass and in excellent condition given its age (both aesthetically and mechanically). Only the box is in bad condition and disintegrates, but a member who will recognize himself kindly offered to help me to remedy this problem ;-)