To prevent the striking train of a clock running too fast, it is controlled by a. "fly," which is a small fan fixed to the last pinion of the train. The fly should be sufficiently tight to turn when the pinion turns. If it is loose, the pinion is liable to run round quickly while the fly stands still and allow the clock to strike too rapidly. Therefore, see that the fly is tight upon its pinion. If it is, and the clock still strikes too fast, try extending the surface of the fly as much as possible by gumming paper to its edges.