A Pendulum Clock
At first glance, the giant see-through-erector-set-like structure seems to be a realization of one of Leonardo da Vinci's mechanical inventions. Totally open and exposed, it is constructed of steel, ropes, bicycle chains and a bowling ball , and stands 24 feet tall. The clock has gear-like teeth protruding from it, marking off the sixty minutes of the hour, as well as a large and a small hand. It is powered by the weight of a large metal basket filled with artifacts which in turn acts on the crown wheel: the key to the clock's turning.