Sand pendulum

Features:
1) Secured in its oak stand, the all metal pendulum converts kinetic energy into
potential energy
2) The extremely fine sand (included) provides minimal friction allowing the pendulum
to swing for extended periods of time
3) As the pendulum swings, it gently "writes" ever changing geometric patterns in
the sand
4) The patterns get bigger then smaller then bigger again as the arc of the pendulum
also changes