The facts and figures behind Olafur Eliassonís The New York City Waterfalls are impressive. Located at four points along the East River in lower Manhattan, the falls cost $15.5 million to build and involved an American-based crew of almost 200 engineers, designers, consultants, permitting specialists and electricians. There were also scores of architects, engineers, craftsmen and assistants employed by Eliassonís own Berlin-based "laboratory for spatial research," not to mention the gargantuan effort of the Public Art Fund. Things were so specialized that on a boat ride the night of the opening a man told me his job was to coordinate the little red lights atop each fall to protect low-flying aircraft. The fact sheet on the falls says the tallest one is higher than the Statue of Liberty; the other three are as tall as nine- to twelve-story buildings. Thatís big.