HART_150914_035
Existing comment: Calder intended Mountains and Clouds to be considered from multiple vantage points. Viewers can climb the mountain, in a sense, by moving up the floors. Each stage of the ascent offers different views -- indeed, different understandings -- of the mountains and clouds. As in actual mountain climbing, the distant clouds gradually become looming clouds during the ascent, until eventually the climber stands above them.

Although the mobile no longer turns today, the clouds originally rotated slowly, driven by an electrical motor installed in the ceiling.
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