There's a good reason why not many Foucault pendulums are built close to

the Equator. As this demonstration shows, not much happens at the Equator!

Here the pendulum at the Equator is started swinging along the North-South

direction, represented by the red line. The entire model, including the earth

and pendulum is slowly rotated in a counterclockwise direction. As the model

earth rotates, notice how the pendulum maintains its swing along the

North-South starting line, even after the earth model has been rotated by

approximately 90 degrees.