WASHINGTON MONUMENT

a marble structure built in a public park on the banks of the Potomac, Washington, D. O._ The cornerstone was laid by President Polk, on July 4, 1848, and the capstone was set in position on December 6, 1884. The foundation is 126% feet square, nearly 37 feet deep, and the walls at the base are 15 feet thick, and inches near the top. It stands 555 d|18 feet above ground, being the highest monument in the world. The walls are constructed of blocks of marble, two feet square, and there are said to be 18,000 of them in the structure, weighing 81,000 tons. An elevator runs up the interior, within the staircase, which has 50 flights, of 18 steps each. The cost of construction was $1,500,000.