The National Underground Railroad Freedom Center opens in Cincinnati this week. Blair Kamin reports that the building is a mixed success. “The architecture of the Freedom Center rises and falls to the extent it exploits and expresses this tension. The museum is, in some respects, powerful and poetic, its undulating travertine walls symbolizing the indirect, often-torturous routes — through mountains and forests, and over rivers — that slaves took to freedom. The trouble is, this sort of poetry doesn’t occur with enough consistency, especially inside, to make the museum the powerhouse combination of intellect and emotion, the visual and the visceral, it might have been.”