Stop works are installed on a grandfather clock so the weights won't hit the seatboard when fully wound up. They also prevent the cable from coming unhooked when the cables are fully let down. Seth Thomas also used stop works on some of their spring driven movements. This insures only the center portion of the spring is used to deliver a more even power source.<p> Stop works are a simple device, they only consists of two gears that mesh together. However they are probably the most misunderstood part of clock work. It is not uncommon to run across a movement which has had the stop works removed because some uninformed repairer didn't know how to reinstall them after disassembling the clock movement. <p>However, this needn't be the case. With this book, and about thirty minutes practice one will no longer be intimidated by stop works.