PHS simulates a 4-pendulum harmonograph.

To show you the kinds of patterns this
program can generate, use the mouse to
move the pointer to the blue area labeled
"Auto-Randomize", then click the left or right
mouse button.  When you see a pattern you like,
click anywhere on the screen to stop
Auto-Randomize.

A real harmonograph has pendulums connected
to a pen and paper that move the two back
and forth to create circular patterns.
