I am in a class and a fellow student wants to put a long pendulum on a movement from shorter case (longer case is nicer and has a window at the bottom to show pendulum). From looking at the "everything you ever wanted to know about pendulum" posting here, https://mb.nawcc.org/showthread.php?114670-All-about-pendulums&highlight=everything+you+wanted+to+know+about+pendulums I understood that a compound pendulum will allow someone to "lengthen" a pendulum's effective length to act as if it were longer (and work slower) than its physical length. In other words I can see how a compound pendulum can make a short pendulum act longer - but I don't see how I can make a long pendulum 'act shorter' .... If she just puts the long one on I assume it will drastically slow down the clock (I am talking about doubling or tripling the length of the current pendulum). Any ideas? Maybe make pendulum heaver at top half and lighter on bottom half with a very light bob? What about one of those pendulum's that have branches that go out to the left and right of the main pendulum assembly?