[Roof Studies], untitled, undated, 02/08/1987, 06/05/1987
Blue, green and black ink sketches on thirteen sheets of tracing paper, 12x11 to 12x28 inches, two sheets of graph paper, 8-1/2x11 inches, and one sheet of white paper, 8-1/2x11 inches, one initialed and dated 2/8/87 and three initialed and dated 6/5/87 with notation "Columbus"