The horizontal line is broken at the midpoint, where a stack of Cor-Ten steel rises above the flat roof like a metaphoric mountain peak.

水平线在中点破开，在一堆十钢涨平屋顶上，像一个隐喻的山峰。

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It was the first building to use Cor-Ten steel, a material that weathers and changes color over time, and it is his most completely resolved and expertly detailed and executed design.

WSJ: Eero Saarinen, Shaping the Future, at the Museum of the City of New York | By Ada Louise Huxtable