he strengths as well as shortcomings of a horizontally coupled chronograph are categorical and well known. While its two-dimensional architecture is visually attractive, the sudden, imperfect mating of the clutch wheel and chronograph seconds wheel results in the ugly jump of the chronograph seconds hand. At the same time, the power needed to drive an additional set of gears causes a momentary loss of balance amplitude. These weaknesses are inherent and uniform across the board as the basic principles of a horizontal coupling system dictate where the main train ends and where the chronograph train starts, thus limiting the design of the movement as whole. One invariable rule by which a traditional horizontal clutch movement is designed is that the fourth wheel always drives a running seconds hand directly and, as a result, is never located in the middle. As such, the construction of a horizontally coupled mechanism is spatially fixed, with each varying little in gear arrangement to another.
