Escapement

 I disassembled the entire movement.  Split this image in half and you have the two separate trains of the movement. The four wheels on the left are the time train and the five on the right are the strike train (that fifth one at the top is not easy to discern in this shot... it's the dark fan). Each train starts at the bottom from its power source. The largest wheels are geared to accept the chains from the weights. The time train is composed of four wheels, signifying that it is an eight day movement, topped by the escape wheel which is easily identified by its sharply pointed teeth.  The fly tops the five wheeled strike train. The addition of a fifth wheel helps slow the speed of the train as does the fly which is that thin, flat fan at the top, made of brass that is built specifically as a kind of braking / regulating system. When it spins the fan slows the train just enough (from wind resistance) to keep the train from moving too fast and thus limits the clock from s...