Washington Monument
Components
Components
----------

### Cornerstone

The [cornerstone](/wiki/Cornerstone "Cornerstone") was laid with great ceremony at the northeast corner of the lowest course or step of the old [foundation](/wiki/%23Foundation "#Foundation") on . Robert Mills, the architect of the monument, stated in September 1848, "The foundations are now brought up nearly to the surface of the ground; the second step being nearly completed, which covers up the corner stone." Therefore, the cornerstone was laid below the 1848 ground level. In 1880, the ground level was raised  to the base of the shaft by the addition of a  wide earthen embankment encircling the reinforced foundation, widened another 30 feet in 1881, and then the knoll was constructed in 1887–88\. If the cornerstone had not been moved during the strengthening of the foundation in 1879–80, its upper surface would now be  below the [pavement](/wiki/Pavers_%28flooring%29 "Pavers (flooring)") just outside the northeast corner of the shaft. It would now be sandwiched between the concrete slab under the old foundation and the concrete buttress completely encircling what remains of the old foundation. During the strengthening process, about half by volume of the periphery of the lowest seven of eight courses or steps of the old foundation (gneiss rubble) was removed to provide good footing for the buttress. Although a few diagrams, pictures and descriptions of this process exist, the fate of the cornerstone is not mentioned.John Milner Associates, [*Historic Structure Report: Washington Monument*](http://www.nps.gov/parkhistory/online_books/wamo/wash_hsr1.pdf) , 2004 (HSR) 

The cornerstone was a  marble block  high and  square with a large hole for a zinc case filled with memorabilia. The hole was covered by a copper plate inscribed with the date of the [Declaration of Independence](/wiki/United_States_Declaration_of_Independence "United States Declaration of Independence") (July 4, 1776\), the date the cornerstone was laid (July 4, 1848\), and the names of the managers of the Washington National Monument Society. The memorabilia in the zinc case included items associated with the monument, the city of Washington, the national government, state governments, benevolent societies, and George Washington, plus miscellaneous publications, both governmental and commercial, a coin set, and a Bible, totaling 73 items or collections of items, as well as 71 newspapers containing articles relating to George Washington or the monument.Frederick L. Harvey, [*History of the Washington National Monument and Washington National Monument Society*](https://books.google.com/books?id=6mVBAQAAMAAJ&pg=PA1), Congressional Serial Set, volume 4436, 57th Congress, 2nd session, Senate Doc. 224, 1903\. The smaller 1902 edition has the slightly different name [*History of the Washington National Monument and of the Washington National Monument Society*](https://archive.org/details/historywashingt00harvgoog). The 1903 edition is about three times the size of the 1902 edition principally due to its inclusion of the full texts of many documents and speeches.

The ceremony began with a parade of dignitaries in carriages, marching troops, fire companies, and benevolent societies. A long oration was delivered by the [Speaker of the House of Representatives](/wiki/Speaker_of_the_United_States_House_of_Representatives "Speaker of the United States House of Representatives") [Robert C. Winthrop](/wiki/Robert_C._Winthrop "Robert C. Winthrop"). Then, the cornerstone was pronounced sound after a [Masonic](/wiki/Masonic "Masonic") ceremony using George Washington's Masonic gavel, apron and sash, as well as other Masonic symbols. In attendance were President [James K. Polk](/wiki/James_K._Polk "James K. Polk") and other federal, state and local government officials, [Elizabeth Schuyler Hamilton](/wiki/Elizabeth_Schuyler_Hamilton "Elizabeth Schuyler Hamilton"), [Mrs. Dolley Madison](/wiki/Dolley_Madison "Dolley Madison"), [Mrs. John Quincy Adams](/wiki/Louisa_Adams "Louisa Adams"), and [George Washington Parke Custis](/wiki/George_Washington_Parke_Custis "George Washington Parke Custis"), among 15,000 to 20,000 others, including a bald eagle. The ceremony ended with fireworks that evening.

### Memorial stones

[thumb\|upright\=1\|alt\=Photo of the Washington Monument Memorial Stone from Utah (State of Deseret)\|Memorial stone from [Utah](/wiki/Utah "Utah"), representing the former provisional [State of Deseret](/wiki/State_of_Deseret "State of Deseret")](/wiki/File:Washington_Monument_Deseret_Stone_in_2000.jpg "Washington Monument Deseret Stone in 2000.jpg")
States, cities, foreign countries, benevolent societies, other organizations, and individuals have contributed 194 memorial stones, all inserted into the east and west interior walls above stair landings or levels for easy viewing, except one on the south interior wall between stairs that is difficult to view. The sources disagree on the number of stones for two reasons: whether one or both "height stones" are included, and stones not yet on display at the time of a source's publication cannot be included. The "height stones" refer to two stones that indicate height: during the first phase of construction a stone with an inscription that includes the phrase "from the foundation to this height 100 feet" () was installed just below the  stairway and high above the  stairway; during the second phase of construction a stone with a horizontal line and the phrase "top of statue on Capitol" was installed on the  level.

The *Historic Structure Report* (HSR, 2004\) named 194 "memorial stones" by level, including both height stones. Jacob (2005\) described in detail and pictured 193 "commemorative stones", including the  stone but not the [Capitol](/wiki/United_States_Capitol "United States Capitol") stone.Judith M. Jacob, [*The Washington Monument: A technical history and catalog of the commemorative stones*](http://www.nps.gov/parkhistory/online_books/wamo/stones.pdf) , 2005\. The *Historic American Buildings Survey* (HABS, 1994\) showed the location of 193 "memorial stones" but did not describe or name any. HABS showed both height stones but did not show one stone not yet installed in 1994\. Olszewski (1971\) named 190 "memorial stones" by level, including the Capitol stone but not the 100\-foot stone. Olszewski did not include three stones not yet installed in 1971\.

Of 194 stones, 94 are marble, 40 are granite, 29 are limestone, 8 are sandstone, with 23 miscellaneous types, including stones with two types of material and those whose materials are not identified. Unusual materials include [native copper](/wiki/Native_copper "Native copper") ([Michigan](/wiki/Michigan "Michigan")), [pipestone](/wiki/Catlinite "Catlinite") ([Minnesota](/wiki/Minnesota "Minnesota")), [petrified wood](/wiki/Petrified_wood "Petrified wood") ([Arizona](/wiki/Arizona "Arizona")), and [jadeite](/wiki/Jadeite "Jadeite") ([Alaska](/wiki/Alaska "Alaska")). The stones vary in size from about  square ([Carthage](/wiki/Carthage "Carthage")) to about  ([Philadelphia](/wiki/Philadelphia "Philadelphia") and New York City).

[Utah](/wiki/Utah "Utah") contributed one stone as a territory and another as a state, both with inscriptions that include its pre\-territorial name, [Deseret](/wiki/State_of_Deseret "State of Deseret"), both located on the  level.

A stone at the  level of the monument is inscribed in  (My Language, My Country, My Nation, Welsh forever). The stone, imported from Wales, was donated by Welsh citizens of [New York](/wiki/New_York_%28state%29 "New York (state)").*[The Cambrian](https://books.google.com/books?id=cXgOAQAAMAAJ&dq=%22Fy+iaith%22&pg=RA1-PA139)*, vol. XVII, p. 139\. 1897\. Two other stones were presented by the Sunday Schools of the [Methodist Episcopal](/wiki/Methodist_Episcopal "Methodist Episcopal") Church in New York and the Sabbath School children of the Methodist Episcopal Church in [Philadelphia](/wiki/Philadelphia "Philadelphia")—the former quotes from the Bible verse Proverbs 10:7, "The memory of the just is blessed".

[Ottoman](/wiki/Ottoman_Empire "Ottoman Empire") [Sultan](/wiki/Sultan "Sultan") [Abdul Mejid I](/wiki/Abdul_Mejid_I "Abdul Mejid I") donated $30,000 toward the construction of the Washington monument. The Sultans' donation was the largest single donation toward the building of the Washington Monument. The Sultan's intention was to bridge peace between the Ottomans and the Americans. The stone containing the [Turkish](/wiki/Ottoman_Turkish "Ottoman Turkish") inscriptions commemorating this event is on the  level. The abbreviated translation of the inscriptions states, "So as to strengthen the friendship between the two countries. Abdul\-Mejid Kahn has also had his name written on the monument to Washington." It combines the works of two eminent [calligraphers](/wiki/Islamic_calligraphy "Islamic calligraphy"): an imperial *[tughra](/wiki/Tughra "Tughra")* by [Mustafa Rakım](/wiki/Mustafa_R%C3%A2kim "Mustafa Râkim")'s student Haşim Efendi, and an inscription in *jalī ta'līq* script by [Kazasker Mustafa Izzet Efendi](/wiki/Kazasker_Mustafa_Izzet_Efendi "Kazasker Mustafa Izzet Efendi"), the calligrapher who wrote the giant medallions at [Hagia Sophia](/wiki/Hagia_Sophia "Hagia Sophia") in [Istanbul](/wiki/Istanbul "Istanbul").[Kadiasker Mustafa Izzet Efendi (1801–1876\)](https://web.archive.org/web/20110119073113/http://calligrapher.wordpress.com/2007/04/06/kadiasker-mustafa-izzet-efendi-1801-%E2%80%93-1876-2/) *Journal of Ottoman Calligraphy*

One stone was donated by the [Ryukyu Kingdom](/wiki/Ryukyu_Kingdom "Ryukyu Kingdom") and brought back by Commodore [Matthew C. Perry](/wiki/Matthew_C._Perry "Matthew C. Perry"),Kerr, George H. *Okinawa: The History of an Island People*. (revised ed.) Tokyo: Tuttle Publishing, 2003\. p337n. but never arrived in Washington (it was replaced in 1989\).
Many of the stones donated for the monument carried inscriptions that did not commemorate George Washington. For example, one from the [Templars of Honor and Temperance](/wiki/Templars_of_Honor_and_Temperance "Templars of Honor and Temperance") stated "We will not make, buy, sell, or use as a beverage, any spiritous or malt liquors, Wine, Cider, or any other Alcoholic Liquor." (George Washington himself had owned a whiskey distillery which operated at [Mount Vernon](/wiki/Mount_Vernon "Mount Vernon") after he left the presidency.)

### Aluminum apex

[thumb\|upright\=1\|Aluminum apex showing inscriptions on its east (left) and north (right) faces](/wiki/File:Aluminum_apex_Repaired_1934.png "Aluminum apex Repaired 1934.png")
The aluminum apex, composed of a metal that at the time was as rare and valuable as silver, was cast by [William Frishmuth](/wiki/William_Frishmuth "William Frishmuth") of [Philadelphia](/wiki/Philadelphia "Philadelphia"). At the time of casting, it was the largest piece of aluminum in the world. Before the installation, it was put on public display at [Tiffany's](/wiki/Tiffany%27s "Tiffany's") in New York City and stepped over by visitors who could say they had "stepped over the top of the Washington Monument". It was  tall before  was vaporized from its tip by lightning strikes during 1885–1934, when it was protected from further damage by tall lightning rods surrounding it. Its base is  square. The angle between opposite sides at its tip is 34°48'. It weighed  before lightning strikes removed a small amount of aluminum from its tip and sides.\[Thomas Lincoln Casey], [*Letter from the Joint Commission for Completion of the Washington Monument, transmitting their annual report. December 15, 1885*](http://infoweb.newsbank.com/iw-search/we/Digital/?p_product=SERIAL&p_theme=sset2&p_nbid=U64Q5BHYMTQyMzY5Njg4NS44MDg5ODg6MToxNToxMzIuMTcwLjIwOC4yMjQ&p_action=doc&p_docnum=1&p_queryname=3&p_docref=v2:0FD2A62D41CEB699@SERIAL-10F552FC5400ED08@-@0) Congressional Serial Set, volume 2333, 49th Congress, 1st session, Senate Doc. 6\. Available for free in most large United States libraries in government documents or online. Establish a connection to [*Readex* collections](http://www.Readex.com/log-through-your-library) before clicking on link. Spectral analysis in 1934 showed that it was composed of 97\.87% aluminum with the rest impurities. It has a shallow depression in its base to match a slightly raised area atop the small upper surface of the marble capstone, which aligns the sides of the apex with those of the capstone, and the downward protruding lip around that area prevents water from entering the joint. It has a large hole in the center of its base to receive a threaded  diameter copper rod which attaches it to the monument and used to form part of the lightning protection system. In 2015 the National Geodetic Survey reported the coordinates of the 1 mm dimple atop the aluminum apex as  (WGS 84\).

The four faces of the external aluminum apex all bear inscriptions in [cursive](/wiki/Cursive "Cursive") writing (Snell [Round hand](/wiki/Round_hand "Round hand")), which are incised into the aluminum. The apex was inscribed on site after it was delivered. Most inscriptions are the original 1884 inscriptions, except for the top three lines on the east face which were added in 1934\. From 1885 to 1934 a wide gold\-plated copper band that held eight short lightning rods, two per side but not at its corners, covered most of the inscriptions, which were damaged and illegible as shown in the accompanying picture made in 1934\. A new band including eight long lightning rods, one at each corner and one at the middle of each side, was added in 1934 and removed and discarded in 2013\. The inscriptions that it covered were still damaged and illegible in 2013\. Only the top four and bottom two lines of the north face, the first and last lines of the west face, the top four lines of the south face, and the top three lines of the east face are still legible. Even though the inscriptions are no longer covered, no attempt was made to repair them when the apex was accessible in 2013\.

The following table shows legible inscriptions in  and illegible inscriptions in . No colors appear on the actual apex. The inscriptions occupy the lower portions of triangles, thus the inscribed upper lines are necessarily shorter than some lower lines.

| North face | West face | South face | East face |
| --- | --- | --- | --- |
|   |  |  |  |

Although most printed sources, Harvey (1903\), Olszewski (1971\), Torres (1984\), and the *Historic Structure Report* (2004\), refer to the original 1884 inscriptions, the National Geodetic Survey (2015\) refers to both the 1884 and 1934 inscriptions. All sources print them according to their own editorial rules, resulting in excessive capitalization (Harvey, Olszewski, and NGS) and inappropriate line breaks. No printed source uses cursive writing, although pictures of the apex clearly show that it was used for both the 1884 and 1934 inscriptions.[External apex east and north faces](http://loc.gov/pictures/resource/thc.5a48088/) [External apex west and south faces](https://www.loc.gov/pictures/resource/thc.5a48091/) 

A replica displayed on the 490\-foot level uses totally different line breaks from those on the external apex—it also omits the 1934 inscriptions. In October 2007, it was discovered that the display of this replica was positioned so that the Laus Deo (Latin for "praise be to God") inscription could not be seen and Laus Deo was omitted from the placard describing the apex. The National Park Service rectified the omission by creating a new display.

### Lightning protection

[thumb\|upright\=1\|Lightning strikes near the Washington Monument](/wiki/File:Three-lighting-strikes-washingtondc-night_-_West_Virginia_-_ForestWander.jpg "Three-lighting-strikes-washingtondc-night - West Virginia - ForestWander.jpg")
The [pyramidion](/wiki/Pyramidion "Pyramidion"), the pointed top  of the monument, was originally designed with an  tall inscribed aluminum apex which served as a single lightning rod, installed . Six months later on  lightning damaged the marble blocks of the pyramidion,M., ["The Washington Monument, and the Lightning Stroke of June 5"](https://books.google.com/books?id=Pw5M1V3DEDUC&pg=PA517) , *Science* 5 (1885\) 517–518\. so a net of gold\-plated copper rods supporting 200  gold\-plated, platinum\-tipped copper points spaced every  was installed over the entire pyramidion. The original net included a gold\-plated copper band attached to the aluminum apex by four large set screws which supported eight closely spaced vertical points that did not protrude above the apex. In 1934 these eight short points were lengthened to extend them above the apex by .Gabriel Escobar, "Workers prepare to fill a tall order", *Washington Post* Tuesday, October 13, 1998, page B1\. In 2013 this original system was removed and discarded. It was replaced by only two thick solid aluminum lightning rods protruding above the tip of the apex by about  attached to the east and west sides of the marble capstone just below the apex.

Until it was removed, the original lightning protection system was connected to the tops of the four iron columns supporting the elevator with large copper rods. Even though the aluminum apex is still connected to the columns with large copper rods, it is no longer part of the lightning protection system because it is now disconnected from the present lightning rods which shield it. The two lightning rods present since 2013 are connected to the iron columns with two large braided aluminum cables leading down the surface of the pyramidion near its southeast and northwest corners. They enter the pyramidion at its base, where they are tied together (electrically shorted) via large braided aluminum cables encircling the pyramidion  above its base. The bottom of the iron columns are connected to ground water below the monument via four large copper rods that pass through a  square well half filled with sand in the center of the foundation. The effectiveness of the lightning protection system has not been affected by a significant draw down of the [water table](/wiki/Water_table "Water table") since 1884 because the soil's water content remains roughly 20% both above and below the height of the water table.Jean\-Louis Briaud *et al*, ["The Washington Monument case history"](http://casehistories.geoengineer.org/volume/volume1/issue3/IJGCH_1_3_3.pdf) , *International Journal of Geoengineering Case Histories* 1 (2009\) 170–188, pp. 176–179\.

### Walls

[thumb\|upright\=1\|Cross section of rubble in shaft at 150\-feet and typical of rubble below 150 feet\|alt\=Showing about 85 irregular large stones in mortar between empty shaft well and outer marble veneer](/wiki/File:Washington_Monument_rubble_at_150_feet.png "Washington Monument rubble at 150 feet.png")
During the first phase of construction (1848–1854\), the walls were built with bluestone gneiss rubble, ranging from very large irregular stones having a cross section of about  down to spalls (broken pieces of stone) all embedded in a large amount of mortar. The outer surface is marble stones  thick in  high courses or rows horizontally encircling the monument. Although each course contains both stretchers (stones parallel to the wall) and headers (stones projecting into the wall), about two to three times as many stretchers as headers were used. Their joints were so thin that some stones pressed on bare stone below them, breaking off many pieces since it was constructed. The batter or slope of the outer surface is 0\.247 inches per foot (2\.06 cm/m, 1°11'). The inner surface has disorderly rows of smaller roughly dressed bluestone gneiss. The base of the first phase walls has an outer dimension of  square and a thickness of . The interior well is  square and has square corners. The weight of the first phase walls up to  is .

During the second phase (1879–1884\), the walls were constructed of smoothly dressed ([ashlar](/wiki/Ashlar "Ashlar")) large marble and granite blocks ([rectangular cuboids](/wiki/Cuboid%23Rectangular_cuboid "Cuboid#Rectangular cuboid")) laid down in an orderly manner ([Flemish bond](/wiki/Flemish_bond "Flemish bond")) with thick joints. Two\-foot high marble surface stones, using an equal number of stretchers and headers, were backed by granite blocks from the 152\-foot level (the first course above the rubble) to the 218\-foot level, where marble headers become increasingly visible on the internal surface of the walls up to the 450\-foot level, above which only marble stones are used.
Between the 150\- and 160\-foot levels the inner walls rapidly slope outward, increasing the shaft well from 25 feet 1 inch square to  square with a corresponding decrease in the thickness of the walls and their weight. The second phase walls at the 160\-foot level were  thick, which, combined with the larger shaft well, yields an outer dimension of  square at that level. The top of the second phase walls are  square and  thick. The second phase interior walls have rounded corners ( radii). The weight of the second phase walls (from 150 feet to 500 feet) are . The walls of the entire shaft (combined first and second phases) are  high.

The first phase of the walls was constructed under the direction of William Dougherty. Its white [Cockeysville marble](/wiki/Cockeysville_Marble "Cockeysville Marble") exterior came from the Texas quarry now adjacent to and east of north I\-83 near the Warren Road exit in [Cockeysville, Maryland](/wiki/Cockeysville%2C_Maryland "Cockeysville, Maryland"). The quarry was named for the Texas Station (no longer extant) and 19th\-century town on the [Northern Central Railway](/wiki/Northern_Central_Railway "Northern Central Railway"). During the first phase it was operated by Thomas Symington, but is now operated by [Martin Marietta Materials](/wiki/Martin_Marietta_Materials "Martin Marietta Materials") and no longer produces building stone. The second phase of construction was under the direction of Lt Col/Col [Thomas Lincoln Casey](/wiki/Thomas_Lincoln_Casey_Sr. "Thomas Lincoln Casey Sr.") of the [United States Army Corps of Engineers](/wiki/United_States_Army_Corps_of_Engineers "United States Army Corps of Engineers"), who removed two defective courses added by the [Know\-Nothings](/wiki/Know_Nothing "Know Nothing") and the last 152\-foot course added by Dougherty before Casey began his construction. The next three courses of white marble () came from [Sheffield, Massachusetts](/wiki/Sheffield%2C_Massachusetts "Sheffield, Massachusetts"), while all courses above them came from the Beaver Dam quarry just west of the 19th\-century town of Cockeysville. The latter quarry is located on Beaver Dam Road near its intersection with McCormick Road. During the second phase the quarry was operated by Hugh Sisson, but is now flooded, is called Beaverdam Pond, and is the home of the Beaver Dam Swimming Club. Both 19th\-century towns are now within the city limits of Cockeysville.

### Pyramidion

[thumb\|upright\=1\|Rib structure of pyramidion with letter designations for courses](/wiki/File:Washington_Monument_pyramidion_rib_structure.png "Washington Monument pyramidion rib structure.png")
The marble capstone of the pyramidion is a truncated pyramid with a cubical keystone projecting from its base and a deep groove surrounding the keystone. The [aluminum apex](/wiki/%23Aluminum_apex "#Aluminum apex") replaces its truncated top. The inside upper edges of the topmost slabs on the four faces of the pyramidion rest on the keystone and in the groove. It has a large vertical hole through which a  threaded copper rod passes and screws into the base of the apex, which used to form part of its [lightning protection system](/wiki/%23Lightning_protection "#Lightning protection"). The keystone and groove occupy so much of its base that only a small horizontal area near its outer edge remains. The weight of the capstone is transferred to both the inner and outer portions of the [shiplap](/wiki/Shiplap "Shiplap") upper edges of the slabs. It weighs , is  high from its base to its top, and is  square at its base.

The marble pyramidion has an extremely complex construction to save weight yet remain strong. Its surface slabs or panels are usually only  thick (with small thick and thin portions) and generally do not support the weight of slabs above them, instead transferring their own weight via  wide internal marble ribs to the shaft's walls. The slabs are generally  wide and  high with a  vertical overlap (shiplap) to prevent water from entering the horizontal joints. Twelve such courses, the internal ribs, the marble capstone, and the aluminum apex comprise the pyramidion. Its height is . Its weight is . The slope of the walls of the pyramidion is 17°24' from the vertical. There are twelve ribs, three per wall, which spring from the  level, all being integrated into the walls up to the  level. All are free standing above 500 feet, relying on [mortise and tenon](/wiki/Mortise_and_tenon "Mortise and tenon") joints to attach neighboring stones. The eight corner ribs terminate six courses above the shaft, each corner rib resting on its neighboring corner rib via a [miter joint](/wiki/Miter_joint "Miter joint"), forming four corner arches. Each such arch supports a pair of square corner stones, one above the other totaling one course in height. Each corner rib is linked to the nearest center rib at the sixth course via a marble tie beam. The four center ribs terminate eight courses above the shaft at a marble cruciform (cross shaped) keystone, forming two main arches that cross each other. Two stones, each one course high, are mounted on each of the four ribs, supporting two additional courses above the cruciform keystone, leaving two courses to support the capstone's weight by themselves.

The observation floor (nominally the 500\-foot level) is  above the entry lobby floor or lowest landing level. It is  above the marble base of the pyramidion and the top of the shaft walls.

Four pairs of  wide observation windows are provided, spaced  apart, inner stone edge to edge, all just above the lowest course of slabs (504\-foot level). Six are  high while two on the east face are  high for easier egress. All were originally provided with thin marble shutters in a bronze frame each of which could be opened inward, one left and the other right per wall. After two people committed suicide by jumping through the open windows in the 1920s, hinged horizontal iron bars were added to them in 1929\. A ninth opening in a slab on the south face just below the capstone is provided for access to the outside of the pyramidion. It is covered by a stone slab which is internally removable. In 1931, four red aircraft warning lights were installed, one per face in one of its observation windows. Pilots complained that they could not be easily seen, so the monument was floodlit on all sides as well. In 1958, eight  diameter holes for new red aircraft warning lights were bored, one above each window near the top edge of the fourth course of slabs (516\-foot level) in the pyramidion. In 1958 the observation windows were glazed with shatterproof glass. In 1974–1976, they were glazed with bulletproof glass and the shutters removed. New bulletproof glass was installed during 1997–2000\.

The pyramidion has two inscriptions, neither of which is regarded as a memorial stone. One is the year "1884" on the underside of the cruciform keystone; the other is at the same level as that keystone on the north face of the west center rib containing the names and titles of the four highest ranked builders. Its inscription (["Chief Engineer ..."](/wiki/Media:Washington_Monument_inscription_interior_pyramidion.png "Washington Monument inscription interior pyramidion.png")) is almost identical to the inscription on the south face of the aluminum apex except for "U.S.", which is part of the phrase "14th U.S. Infantry" in the inscription inside the pyramidion, but the apex has only "14th Infantry". Additionally, the internal inscription does not use cursive writing and all letters in all names are capitals.

### Foundation

[thumb\|upright\=1\|Cross section of foundation, both old and reinforced, showing dimensions](/wiki/File:Washington_Monument_foundation.png "Washington Monument foundation.png")
The first phase began with the excavation of about  of topsoil down to a level of [loam](/wiki/Loam "Loam"), consisting of equal parts of sand and clay, hard enough to require [picks](/wiki/Pickaxe "Pickaxe") to break it up. On this "bed of the foundation" the [cornerstone](/wiki/%23Cornerstone "#Cornerstone") was laid at the northeast corner of the proposed foundation. The rest of the foundation was then constructed of bluestone gneiss rubble and spalls, with every crevice filled with [lime mortar](/wiki/Lime_mortar "Lime mortar"). The dimensions of this old foundation were  high,  square at the base, and  square at the top, laid down in eight steps, similar to a truncated [step pyramid](/wiki/Step_pyramid "Step pyramid"). At the center of the foundation a brick\-lined  square well was dug to a depth of  below the bed of the foundation to keep it dry and to supply water during construction.

During the second phase, after determining that the proposed weight of the monument was too great for the old foundation to safely bear, the thickness of the walls atop the unfinished stump was reduced and the foundation was strengthened by adding a large unreinforced concrete slab below the perimeter of the old foundation to increase the monument's load bearing area two and one half times. The slab was  thick, with an outer perimeter  square, an inner perimeter  square, with undisturbed loam inside the inner perimeter except for the water well. The area at the base of the second phase foundation is . The strengthened foundation (old foundation and concrete slab) has a total depth of  below the bottom of the lowest course of marble blocks (now below ground), and  below the entry lobby floor. Casey reported that nowhere did the load exceed  and did not exceed  near the outer perimeter. To properly distribute the load from the shaft to slab, about half by volume of the outer periphery of the old rubble foundation below its top step was removed. A continuous sloping unreinforced concrete buttress encircles what remains. The buttress is  square at its base,  square at its top, and  high. The perimeter of the original top step of the old rubble foundation rests on the larger top of the concrete buttress. Its slope (lower external angle from the vertical) is 49°. This buttress rests in a depression (triangular cross\-section) on the top surface of the concrete slab. The slab was constructed by digging pairs of  wide [drifts](/wiki/Drift_mining "Drift mining") on opposite sides of the monument's center line to keep the monument properly balanced. The drifts were filled with unreinforced concrete with depressions or dowel stones on their sides to interlock the sections. An earthen terrace  wide with its top at the base of the walls and steep sides was constructed in 1880–81 over the reinforced foundation while the rest of the monument was being constructed. During 1887–88, a knoll was constructed around the terrace tapering out roughly  onto the surrounding terrain. This earthen terrace and knoll serves as an additional buttress for the foundation. The weight of the foundation is , including earth and gneiss rubble above the concrete foundation that is within its outer perimeter.

### Stairs and elevator

[thumb\|right\|upright\=1\|North interior wall with its stairs and their wire screening](/wiki/File:Sections_-_Washington_Monument%2C_High_ground_West_of_Fifteenth_Street%2C_Northwest%2C_between_Independence_and_Constitution_Avenues%2C_Washington%2C_District_of_Columbia%2C_DC_HABS_DC%2CWASH%2C2-_%28sheet_31_of_37%29.png "Sections - Washington Monument, High ground West of Fifteenth Street, Northwest, between Independence and Constitution Avenues, Washington, District of Columbia, DC HABS DC,WASH,2- (sheet 31 of 37).png")
The monument is filled with ironwork, consisting of its stairs, elevator columns and associated tie beams, none of which supports the weight of the stonework. It was redesigned in 1958 to reduce congestion and improve the flow of visitors. Originally, visitors entered and exited the west side of the elevator on the observation floor, causing congestion. So the large landing at the 490\-foot level was expanded to a full floor and the original spiral stair in the northeast corner between the  levels was replaced by two spiral stairs in the northeast and southeast corners. Now visitors exit the elevator on the observation floor, then walk down either spiral stair before reboarding the elevator for their trip back down.

The main stairs spiral up the interior walls from the entry lobby floor to the elevator reboarding floor at the  level. The elevator occupies the center of the shaft well from the entry lobby to the observation floor, with an elevator machine room (installed 1925–26\) whose floor is  above the observation floor and an elevator pit (excavated 1879\) whose floor is  below the entry lobby floor. The stairs and elevator are supported by four wrought iron columns each. The four supporting the stairs extend from the entry lobby floor to the observation floor and were set at the corners of a  square. The four supporting the elevator extend from the floor of the elevator pit to  above the observation floor and were set at the corners of a  square. The weight of the ironwork is . [Cast iron](/wiki/Cast_iron "Cast iron"), [wrought iron](/wiki/Wrought_iron "Wrought iron"), and steel were all used. The two small spiral stairs installed in 1958 are aluminum.

Most landings occupy the entire east and west interior walls every  from and including the east landing at the  level up to the west landing at the  level, east then west alternately. Three stairs with small landings rise from the entry lobby floor to the  level successively along the north, west and south interior walls. Landings from the  level up to the  level are  by , while landings from the  level to the  level are  by . All stairs are on the north and south walls except for the aforementioned west stair between the  levels, and the two spiral stairs.

About one fourth of visitors chose to ascend the monument using the stairs when they were available. They were closed to up traffic in 1971, and then closed to all traffic except by special arrangement in 1976\. The stairs had 898 steps until 1958, consisting of 18 [risers](/wiki/Stair_riser "Stair riser") in each of the 49 main stairs plus 16 risers in the spiral stair. Since 1958 the stairs have had 897 risers if only one spiral stair is counted because both spiral stairs now have 15 risers each. These figures do not include two additional steps in the entry passage that were covered up in 1975 by a ramp and its inward horizontal extension to meet the higher (since 1886\) entry lobby floor. One step was  away from the outer walls and the other was at the end of the passage,  away from the outer walls.

As initially constructed, the interior was relatively open with two\-rail [handrails](/wiki/Handrail "Handrail"), but a couple of suicides and an accidental fall prompted the addition of tall wire screening  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](/wiki/Dynamo "Dynamo") in 1901 which took five minutes to ascend. The monument was connected to the [electrical grid](/wiki/Electrical_grid "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. From 1997 to 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 while passing them during its descent.

### Flags

[thumb\|upright\=1\|50 American flags representing the 50 U.S. states surround the Washington Monument.](/wiki/File:Overhead_view_of_Washington_Monument.jpg "Overhead view of Washington Monument.jpg")
Fifty [American flags](/wiki/Flag_of_the_United_States "Flag of the United States") (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  tall aluminum flag poles (anticipating Alaska and Hawaii) were installed, evenly spaced around a  diameter circle. During 2004–05, the diameter of the circle was reduced to . Since Washington's birthday 1958, 48 American flags were flown on a daily basis, increasing to 49 flags on , and then to 50 flags since . 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 , 50 American flags have flown 24 hours a day.[Michael D. Hoover, *The origins and history of the Washington Monument flag display*, 1992](http://www.nps.gov/parkhistory/online_books/wamo/flag.pdf) 

### Vesica piscis

[thumb\|upright\=1\|The monument stands at a height of about 555 feet.](/wiki/File:Washington_Monument_-_night.JPG "Washington Monument - night.JPG")
In the 2004 grounds renovation, two large circles were added to the landscaping with the obelisk in the intersection or [vesica piscis](/wiki/Vesica_piscis "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.

### Miscellaneous details

The total cost of the monument from 1848 to 1888 was $1,409,500Charles W. Snell, [A Brief History of the Washington Monument and Grounds, 1783–1978](http://www.nps.gov/parkhistory/online_books/wamo/wamo_history.pdf)  (1978\) 17–19\. ().[Download Conversion Factors](http://liberalarts.oregonstate.edu/spp/polisci/faculty-staff/robert-sahr/inflation-conversion-factors-years-1774-estimated-2024-dollars-recent-years/download-conversion-factors)  Oregon State University. The weight of the above ground portion of the monument is , whereas its total weight, including the foundation below ground and any earth above it that is within its outer perimeter is . 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\.

The monument stands  tall according to the National Geodetic Survey (measured 2013–14\) or  tall according to the [National Park Service](/wiki/National_Park_Service "National Park Service") (measured 1884\). In 1975, a ramp covered two steps at the entrance to the monument, so the ground next to the ramp was raised to match its height, reducing the remaining height to the monument's apex. It is both the world's tallest predominantly stone structure and the world's tallest obelisk. It is the tallest monumental column in the world if all are measured above their pedestrian entrances, but two are taller when measured above ground, though they are neither all stone nor true obelisks. The tallest [masonry structure](/wiki/Masonry_structure "Masonry structure") in the world is the brick [Anaconda Smelter Stack](/wiki/Anaconda_Smelter_Stack "Anaconda Smelter Stack") in [Montana](/wiki/Montana "Montana") at  tall. But this includes a  non\-masonry concrete foundation, leaving the stack's brick chimney at  tall, only about  taller than the monument's 2015 height. If the monument's aluminum apex is also discounted, then the stack's masonry portion is  taller than the monument's masonry portion.

### Security

[thumb\|upright\=1\|A low\-profile [ha\-ha](/wiki/Ha-ha "Ha-ha") wall surrounds the monument.](/wiki/File:Buildings_in_Washington%2C_D.C._01907_%28cropped%29_ha-ha_wall_2.JPG "Buildings in Washington, D.C. 01907 (cropped) ha-ha wall 2.JPG")
In 2001, a temporary visitor security screening center was added to the east entrance of the Washington Monument in the wake of the [September 11 attacks](/wiki/September_11_attacks "September 11 attacks"). The one\-story facility was designed to reduce the ability of a terrorist attack on the interior of the monument, or an attempt to seize and hold it. Visitors obtained their timed\-entry tickets from the Monument Lodge east of the memorial and passed through metal detectors and bomb\-sniffing sensors prior to entering the monument. After exiting the monument, they passed through a turnstile to prevent them from re\-entering. This facility, a one\-story cube of wood around a metal frame, was intended to be temporary until a new screening facility could be designed.[National Park Service and National Capital Planning Commission. "Visitor Screening Facility, Washington Monument Between 14th and 17th Streets, NW and Constitution Avenue, NW and the Tidal Basin." Executive Director's Recommendation. NCPC File Number 6176\. March 6, 2014, pp. 5, 7](http://www.ncpc.gov/DocumentDepot/Actions_Recommendations/2014March/Washington_Monument_Visitor_Screening_Facility_Recommendation_6176_March2014_.pdf) . Retrieved March 7, 2014\.

On March 6, 2014, the [National Capital Planning Commission](/wiki/National_Capital_Planning_Commission "National Capital Planning Commission") approved a new visitor screening facility to replace the temporary one. The  facility will be two stories high and contain space for screening 20 to 25 visitors at a time. The exterior walls (which will be slightly frosted to prevent viewing of the security screening process) will consist of an outer sheet of [bulletproof glass](/wiki/Bulletproof_glass "Bulletproof glass") or [polycarbonate](/wiki/Polycarbonate "Polycarbonate"), a metal mesh insert, and another sheet of bulletproof glass. The inner sheet will consist of two sheets (slightly separated) of [laminated glass](/wiki/Laminated_glass "Laminated glass"). A  airspace will exist between the inner and outer glass walls to help insulate the facility. Two (possibly three) [geothermal heat pumps](/wiki/Geothermal_heat_pump "Geothermal heat pump") will be built on the north side of the monument to provide heating and cooling of the facility. The new facility will also provide an office for National Park Service and United States Park Police staff. The structure is designed so that it may be removed without damaging the monument.[Neibauer, Michael. "Here's Where You'll Queue to Visit the Washington Monument." *Washington Business Journal.* March 7, 2014](http://www.bizjournals.com/washington/breaking_ground/2014/03/heres-where-youll-queue-to-visit-the.html) . Retrieved March 7, 2014\. The [United States Commission of Fine Arts](/wiki/United_States_Commission_of_Fine_Arts "United States Commission of Fine Arts") approved the aesthetic design of the screening facility in June 2013\.[National Park Service and National Capital Planning Commission. "Visitor Screening Facility, Washington Monument Between 14th and 17th Streets, NW and Constitution Avenue, NW and the Tidal Basin." Executive Director's Recommendation. NCPC File Number 6176\. March 6, 2014, pp. 15–16](http://www.ncpc.gov/DocumentDepot/Actions_Recommendations/2014March/Washington_Monument_Visitor_Screening_Facility_Recommendation_6176_March2014_.pdf) . Retrieved March 7, 2014\.

A recessed trench wall known as a [ha\-ha](/wiki/Ha-ha "Ha-ha") has been built to minimize the visual impact of a security barrier surrounding the monument. After the [September 11 attacks](/wiki/September_11_attacks "September 11 attacks") and another unrelated terror threat at the monument, authorities had put up a circle of temporary [Jersey barriers](/wiki/Jersey_barrier "Jersey barrier") to prevent large motor vehicles from approaching. The unsightly barrier was replaced by a less\-obtrusive low  granite stone wall that doubles as a seating bench and also incorporates lighting. Designed by the famed landscape architect [Laurie Olin](/wiki/Laurie_Olin "Laurie Olin"), the installation received the 2005 Park/Landscape Award of Merit from the [American Society of Landscape Architects](/wiki/American_Society_of_Landscape_Architects "American Society of Landscape Architects").[Washington Monument](http://www.theolinstudio.com/flash#/projects/type/washington-monument)  (from the [OLIN](/wiki/OLIN "OLIN") website)\[[https://www.asla.org/awards/2008/08winners/236\.html](https://www.asla.org/awards/2008/08winners/236.html) Monument Security] (from the [American Society of Landscape Architects](/wiki/American_Society_of_Landscape_Architects "American Society of Landscape Architects") website, ASLA awards 2006\)


How will the new facility provide an office for National Park Service and United States Park Police staff?