In January 2003 British sculptor Andy Goldsworthy was invited to create a work of art for the National Gallery of Art. The project began with a series of ephemeral works on Government Island in Stafford County, Virginia. From this phase a series of photographic suites and a diary remain. The second phase of the project resulted in Roof, a permanent, site-specific sculpture at the National Gallery comprising nine stacked-slate domes installed over...