Flanking the main entrance to the Minneapolis Sculpture Garden is Ampersand, a sculpture by Martin Puryear made with two 14-foot granite columns. The artist sculpted the columns from a single rectangular block of granite that he split in two. Then he used a machine lathe--similar to a giant pencil sharpener--to shape each piece into its final form. The artist intentionally left a portion of the column "unfinished" to emphasize the texture and natural quality of the stone. Like the Garden, which is symmetrical and balanced in its layout, the columns are nearly identical. However, Puryear varies the symmetry of the columns by installing them in opposite directions--one on its cylindrical end, the other on its square base. By doing this, the artist calls attention to the smooth, polished, round shape of one column and the rough texture and massive rectangular shape of the other column.