The visitor turns a crank that drives a generator. Immediately a light bulb and 3 leds leading to the tower come on and whose brightness is related to how fast the crank is turned. As the crank is turned the led lights on each floor of the tower start to turn on from the bottom in sequence. The two red tower top leds come on as soon as the bottom row is lit up. When the visitor stops cranking the tower lights all go off.