<P> As initially constructed, the interior was relatively open with two - rail handrails, but a couple of suicides and an accidental fall prompted the addition of tall wire screening (7 feet (2.1 m) high with a large diamond mesh) on the inside edge of the stairs and landings in 1929 . The original steam powered elevator, which took 10 to 12 minutes to ascend to the observation floor, was replaced by an electric elevator powered by an on - site dynamo in 1901 which took five minutes to ascend . The monument was connected to the electrical grid in 1923, allowing the installation of a modern electric elevator in 1925--26 which took 70 seconds . The latter was replaced in 1958 and again in 1998 by 70 - second elevators . During 1997--2000, the wire screening at three platforms was replaced by large glass panels to allow visitors on the elevator to view three clusters of memorial stones that were synchronously lit as the elevator automatically slowed as it passed them during its descent . </P> <P> Fifty American flags (not state flags), one for each state, are now flown 24 hours a day around a large circle centered on the monument . Forty eight American flags (one for each state then in existence) were flown on wooden flag poles on Washington's birthday since 1920 and later on Independence Day, Memorial Day, and other special occasions until early 1958 . Both the flags and flag poles were removed and stored between these days . In 1958 fifty 25 - foot (7.6 m) tall aluminum flag poles (anticipating Alaska and Hawaii) were installed, evenly spaced around a 260 - foot (79 m) diameter circle . During 2004--05, the diameter of the circle was reduced to 240 feet (73 m). Since Washington's birthday 1958, 48 American flags were flown on a daily basis, increasing to 49 flags on July 4, 1959, and then to 50 flags since July 4, 1960 . When 48 and 49 flags were flown, only 48 and 49 flag poles of the available 50 were placed into base receptacles . All flags were removed and stored overnight . Since July 4, 1971, 50 American flags have flown 24 hours a day . </P> <P> In the 2004 grounds renovation, two large circles were added to the landscaping with the obelisk in the intersection or vesica piscis . The monument's vesica piscis is not ideal because neither circle passes through the center of its neighbor . Furthermore, both "circles" are slightly elliptical . </P> <P> The total cost of the monument from 1848 to 1888 was $1,409,500 (equivalent to $30,000,000 in 2016). The weight of the above ground portion of the monument is 44,208 long tons (49,513 short tons; 44,917 tonnes), whereas its total weight, including the foundation below ground and any earth above it that is within its outer perimeter is 81,120 long tons (90,854 short tons; 82,422 tonnes). The total number of blocks in the monument, including all marble, granite and gneiss blocks, whether externally or internally visible or hidden from view within the walls or old foundation is over 36,000 . The number of marble blocks externally visible is about 10,000 . </P>

What is on the top of the washington monument