The name Type 20 originates from a French Ministry of War directive, which ordered that all of its military units be equipped with chronographs which had a flyback function. This function provided sailors and pilots with a quick and reliable device on which they could rely, notably for precisely calculating when to change course. They also needed to be able to precisely calculate longitudes in order to avoid making mistakes with regard to course and targets. Until that time, four separate actions had been required in order to achieve the equivalent of the flyback function (that is, to start the chronometer, reset it to zero and then restart it): start, stop, reset to zero, start. With the Type 20 model, only two actions were required for the flyback function: Pressing the button above 2 o’clock starts the chronograph:
URL:
http://en.auricoste.abemadi.com/?
Photo:
http://www.prlog.org/




