Japan's Osaka Station City is filled with public clocks, but there's one timepiece that's more striking than most: the Water Clock in the complex's South Gate building, by Japanese mechatronics manufacturer Koei Industry. A work of high-tech art, the Water Clock delivers digital time using H2O and space printing. At the top of the clock are 400 computer-controlled nozzles that dispense water in both preprogrammed patterns, in shapes such as musical notes, and as a numeric display of the actual time. After the water falls and tells the time, it collects in a basin at the bottom of the clock to be recirculated into the system. Altogether the clock requires 30 liters of water per minute.
Four Canadian engineering students created the Iron Ring Clock as their thesis project in 2003. The nearly 5-foot-tall timepiece is now on display at their alma mater, McMaster University in Hamilton, Ontario. The clock, named for the rings most Canadian engineering students wear upon graduating, uses a synchronous electric motor, which synchronizes with the frequency of electricity it receives. Two stainless steel rings more than 3 feet in diameter rotate independently. The lower ring displays the minutes, while the upper ring, which displays the hour, uses a Geneva-drive mechanism to slow down its rotation. The rings are decorated with 6-inch-high numbers that, when read straight on, tell the time. A stained-glass portrayal of the McMaster crest stands between the two rings, doing double duty as a school symbol and as a cover for the clock's mechanical drives and power-transmission systems.