"Details of Peristyle of Dome," by Thomas U. Walter, Ink and Watercolor on Paper, 1857
In order to make the dome as broad and tall as possible, the dome’s designers decided to cantilever the lower ring of columns beyond the existing rotunda walls and to drop a skirt in front to give it a visual sense of support. Consequently, the lower diameter of the new dome was about 30 feet wider than the old dome. This pleased members of Congress as well as the designers, all of whom wanted the Capitol’s new dome to be as big and as imposing as conditions allowed.
Architect of the Capitol