Fatton's patent No. 4645 of February 9, 1822 concerned an ?astronomical instrument or watch, by which the time of the day, the progress of the celestial bodies, as well of carriages, horses or other animals, may be correctly ascertained? making this one of the earliest inking chronographs.In inking chronographs,when a push-button in the pendant is depressed, the chronograph hand deposits a small drop of ink on the dial. Depressing the pushbutton, which in turn lifts one portion of the chronograph hand, takes time; this is only a fraction of a second, but in precise time measurement it is significant. In Fatton's chronograph this small time interval is minimized by the ingenious incorporation of the strength of the mainspring barrel. It has a device similar to an escapement that, upon depressing the pushbutton, releases the mainspring barrel, which takes over and almost instantaneously lifts part of the chronograph hand causing an ink deposit. The solution is far from intuitively obvio s. Most watchmakers would never think of releasing the click from the barrel to let it loose; this is how pinions and wheels are broken! Fatton used this force, via escapement-like device, to let the barrel down in a controlled manner, allowing superior control over the measurement of small time intervals. Frederick Louis Fatton Was one of Breguet's most eminent pupils and one of his London agents. He settled in New Bond Street, London, and made many fine watches and clocks in the Breguet style, which he frequently signed ?Fatton élève de Breguet?.