The New International Encyclopædia/Washington Monument

WASHINGTON MONUMENT. A huge obelisk erected in the city of Washington, having a total height of 555 feet 5⅛ inches. It is the highest masonry structure in the world. The cornerstone was laid in 1848 and work on the monument continued slowly until 1877, when it ceased, but was resumed in 1878, and finished in 1884. The Washington National Monument Society originated the plan and controlled the work of construction until 1877, when its property was conveyed to the United States. Maryland marble is the material out of which the monument was constructed. The foundation covers an area of 16,000 feet, and weighs 36,912 gross tons. The shaft is 55 feet 1.5 inches square at the bottom, 34 feet 5.5 inches square at the top, weighs 43,633 gross tons, and is 500 feet 5⅛ inches high; the apex, weighing 300 tons, is 55 feet high, its summit being nearly 600 feet above the tidewater of the Potomac. The apex is capped by an aluminum point. It has 262 marble pieces, of seven-inch thickness. Toward the cost of erection the Monument Society had expended $300,000; the total cost has been $1,187,710.31. Lieutenant-Colonel T. L. Casey, of the United States Engineers, had charge of the work of construction after its passing under the control of the United States. The original designs were by Robert Mills. An elevator and an iron stairway of 900 steps within the monument afford access to the base of the apex.