Ledge has applications in mining, architecture, shipbuilding, carpentry, printing, and geology, and is used to describe the outside boundary or overhanging edge of a surface. Ledges can be jagged outward projections, or they can run in long narrow shelves from mountains, cliffs, or buildings. Standing on a ledge, one feels both the precariousness of being suspended above and over a space and the thrill of looking out and being drawn to the beauty and mystery of an expanse. Certainly this is what one experiences when standing on the brittle and crumbling sandstone ledges along the top of Canyon de Chelly in Arizona. And when William Meredith writes, in “The Wreck of the Thresher,” “I stand on a ledge where rock runs into the river/As night turns brackish with morning, and mourn the drowned,” one fathoms not only the depth of the sea that waits beyond the ledge but the depth of grief that leads the poet to elegize the lost submariners.