This odd clock is at the europa center. There's a pump somewhere, and it keeps time. A bulb at the top center fills over the course of a few seconds, filling some tubes next to the large glass spheres over the course of two minutes. Then, that water drains away and one of the discs on the right fills. When that column fills, it drains away and one of the bulbs on the right fills to mark the beginning of the next hour. It's fun to watch.
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