An elliptical dome, or an ''oval dome'', is a

dome A dome () is an architectural element similar to the hollow upper half of a sphere. There is significant overlap with the term cupola, which may also refer to a dome or a structure on top of a dome. The precise definition of a dome has been a m ...

whose bottom

cross-section Cross section may refer to: * Cross section (geometry) ** Cross-sectional views in architecture and engineering 3D * Cross section (geology) * Cross section (electronics) * Radar cross section, measure of detectability * Cross section (physics) ...

takes the form of an

ellipse In mathematics, an ellipse is a plane curve surrounding two focus (geometry), focal points, such that for all points on the curve, the sum of the two distances to the focal points is a constant. It generalizes a circle, which is the special ty ...

. Technically, an '' ellipsoidal dome'' has a circular cross-section, so is not quite the same. While the

cupola In architecture, a cupola () is a relatively small, usually dome-like structure on top of a building often crowning a larger roof or dome. Cupolas often serve as a roof lantern to admit light and air or as a lookout. The word derives, via Ital ...

can take different

geometries Geometry is a branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space. Geometry is one of the oldest mathematical sciences. Types, methodologies, and terminologies of geometry. ...

, when the ceiling's cross-section takes the form of an ellipse, and due to the reflecting properties of an ellipse, any two persons standing at a

focus Focus (: foci or focuses) may refer to: Arts * Focus or Focus Festival, former name of the Adelaide Fringe arts festival in East Australia Film *Focus (2001 film), ''Focus'' (2001 film), a 2001 film based on the Arthur Miller novel *Focus (2015 ...

of the floor's ellipse can have one whisper, and the other hears; this is a whispering gallery. The largest elliptical dome in the world is at the Sanctuary of Vicoforte in Vicoforte,

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

In architecture

Elliptical domes have many applications in

architecture Architecture is the art and technique of designing and building, as distinguished from the skills associated with construction. It is both the process and the product of sketching, conceiving, planning, designing, and construction, constructi ...

; and are useful in covering rectangular spaces. The

oblate In Christianity (specifically the Roman Catholic, Orthodox, Lutheran, Anglican and Methodist traditions), an oblate is a person associated with a Benedictine monastery or convent who is specifically dedicated to God and service. Oblates are i ...

, or horizontal elliptical dome is useful when there is a need to limit height of the space that would result from a spherical dome. As the

mathematical Mathematics is a field of study that discovers and organizes methods, Mathematical theory, theories and theorems that are developed and Mathematical proof, proved for the needs of empirical sciences and mathematics itself. There are many ar ...

description of an elliptical dome is more complex than that of spherical dome, design care is needed. In a

geodesic dome A geodesic dome is a hemispherical thin-shell structure (lattice-shell) based on a geodesic polyhedron. The rigid triangular elements of the dome distribute stress throughout the structure, making geodesic domes able to withstand very heavy ...

with a circular base, the triangular elements align so their edges form

great circles In mathematics, a great circle or orthodrome is the circular intersection of a sphere and a plane passing through the sphere's center point. Discussion Any arc of a great circle is a geodesic of the sphere, so that great circles in spheric ...

. Although not geodesic, a new, elliptical design was patented in 1989; it uses hexagons and pentagons to form a dome with a cross section that is elliptical. Due to its mathematical derivation, this design is called " geotangent".

World examples

Elliptical domes come up in the design of all of the following: * A number of

mosques A mosque ( ), also called a masjid ( ), is a place of worship for Muslims. The term usually refers to a covered building, but can be any place where Islamic prayers are performed; such as an outdoor courtyard. Originally, mosques were simple p ...

Cairo, Egypt Cairo ( ; , ) is the Capital city, capital and largest city of Egypt and the Cairo Governorate, being home to more than 10 million people. It is also part of the List of urban agglomerations in Africa, largest urban agglomeration in Africa, L ...

, * Part of

St. Peter's Basilica The Papal Basilica of Saint Peter in the Vatican (), or simply St. Peter's Basilica (; ), is a church of the Italian High Renaissance located in Vatican City, an independent microstate enclaved within the city of Rome, Italy. It was initiall ...

, in

Rome Rome (Italian language, Italian and , ) is the capital city and most populated (municipality) of Italy. It is also the administrative centre of the Lazio Regions of Italy, region and of the Metropolitan City of Rome. A special named with 2, ...

* The Basilica of St. Lawrence, Asheville, in Asheville,

North Carolina North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...

, * The Church of Saint Roch, Žižkov, in

Prague Prague ( ; ) is the capital and List of cities and towns in the Czech Republic, largest city of the Czech Republic and the historical capital of Bohemia. Prague, located on the Vltava River, has a population of about 1.4 million, while its P ...

Czech Republic The Czech Republic, also known as Czechia, and historically known as Bohemia, is a landlocked country in Central Europe. The country is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the south ...

, * The Four Domes Pavilion, in Wroclaw, Poland, * The Indiana Theatre, in

Indiana Indiana ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Michigan to the northwest, Michigan to the north and northeast, Ohio to the east, the Ohio River and Kentucky to the s ...

, city of

Indianapolis Indianapolis ( ), colloquially known as Indy, is the List of capitals in the United States, capital and List of municipalities in Indiana, most populous city of the U.S. state of Indiana and the county seat of Marion County, Indiana, Marion ...

, * The Joe and Rika Mansueto Library, at the

University of Chicago The University of Chicago (UChicago, Chicago, or UChi) is a Private university, private research university in Chicago, Illinois, United States. Its main campus is in the Hyde Park, Chicago, Hyde Park neighborhood on Chicago's South Side, Chic ...

, * The Kanteerava Indoor Stadium, in

Bangalore, India Bengaluru, also known as Bangalore (List of renamed places in India#Karnataka, its official name until 1 November 2014), is the Capital city, capital and largest city of the southern States and union territories of India, Indian state of Kar ...

, * The

Mayflower Hotel The Mayflower Hotel is a historic hotel in downtown Washington, D.C., located on Connecticut Avenue NW. It is two blocks north of Farragut Square and one block north of the Farragut North (Washington Metro), Farragut North Washington Metro, Me ...

, in

Washington, DC Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and Federal district of the United States, federal district of the United States. The city is on the Potomac River, across from ...

, * The

Mosque–Cathedral of Córdoba The Mosque–Cathedral of Córdoba ( ), officially known by its ecclesiastical name of Cathedral of Our Lady of the Assumption (), is the cathedral of the Roman Catholic Diocese of Córdoba, Diocese of Córdoba dedicated to the Assumption of Ma ...

, in

Andalusia Andalusia ( , ; , ) is the southernmost autonomous communities of Spain, autonomous community in Peninsular Spain, located in the south of the Iberian Peninsula, in southwestern Europe. It is the most populous and the second-largest autonomou ...

, * The

Palau Nacional The (Catalan language, Catalan for 'National Palace') is a building on the hill of Montjuïc (Barcelona), Montjuïc in Barcelona. It was the main site of the 1929 Barcelona International Exposition, 1929 International Exhibition. It was designed ...

, in

Barcelona Barcelona ( ; ; ) is a city on the northeastern coast of Spain. It is the capital and largest city of the autonomous community of Catalonia, as well as the second-most populous municipality of Spain. With a population of 1.6 million within c ...

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

, * The

Pisa Cathedral Pisa Cathedral (), officially the Primatial Metropolitan Cathedral of the Assumption of Mary (), is a medieval Catholic cathedral dedicated to the Assumption of the Virgin Mary, in the Piazza dei Miracoli in Pisa, Italy, the oldest of the three s ...

, in

Pisa, Italy Pisa ( ; ) is a city and ''comune'' (municipality) in Tuscany, Central Italy, straddling the Arno just before it empties into the Ligurian Sea. It is the capital city of the Province of Pisa. Although Pisa is known worldwide for the Leaning Tow ...

, * The

Rose Hill Mansion, Bluffton Rose Hill Plantation House (sometimes Rose Hill Mansion) is an historic Carpenter Gothic house located on US 278 in Bluffton, South Carolina, Bluffton, Beaufort County, South Carolina, Beaufort County, South Carolina. It was begun in 1858 for ...

, in

Bluffton, South Carolina Bluffton is a town in southern Beaufort County, South Carolina, United States. The population as of the 2020 United States Census, 2020 census was 27,716, an increase of over 120% since the 2010 United States census, 2010 census, making it the Li ...

, * The San Filippo Neri, in

Turin Turin ( , ; ; , then ) is a city and an important business and cultural centre in northern Italy. It is the capital city of Piedmont and of the Metropolitan City of Turin, and was the first Italian capital from 1861 to 1865. The city is main ...

, region of

Piedmont Piedmont ( ; ; ) is one of the 20 regions of Italy, located in the northwest Italy, Northwest of the country. It borders the Liguria region to the south, the Lombardy and Emilia-Romagna regions to the east, and the Aosta Valley region to the ...

, Italy, * The

Sant'Andrea in Via Flaminia Sant'Andrea in Via Flaminia () is a Roman Catholic churches of Rome, church dedicated to St Andrew the Apostle in Rome, Italy. The edifice is also known as ''Sant'Andrea del Vignola'', after its architect Giacomo Barozzi da Vignola. History It w ...

, in

Rome, Italy Rome (Italian language, Italian and , ) is the capital city and most populated (municipality) of Italy. It is also the administrative centre of the Lazio Regions of Italy, region and of the Metropolitan City of Rome. A special named with 2, ...

, * The Santa Caterina, Casale Monferrato, in

Casale Monferrato Casale Monferrato () is a town in the Piedmont region of Northwest Italy, northwestern Italy, in the province of Alessandria. It is situated about east of Turin on the right bank of the Po River, Po, where the river runs at the foot of the Montfe ...

Province of Alessandria The province of Alessandria (; ; in Piedmontese of Alessandria: ''provinsa ëd Lissändria'') is an Italian Provinces of Italy, province, with a population of some 425,000, which forms the southeastern part of the region of Piedmont. The prov ...

, region of

, Italy, * The

Seville Cathedral The Cathedral of Saint Mary of the See (), better known as Seville Cathedral (), is a Catholic cathedral and former mosque in Seville, Andalusia, Spain. It was registered in 1987 by UNESCO as a World Heritage Site, along with the adjoining Alc� ...

, Spain, * The Skyspace Lech, Tannegg/ Oberlech in

Vorarlberg Vorarlberg ( ; ; , , or ) is the westernmost States of Austria, state () of Austria. It has the second-smallest geographical area after Vienna and, although it also has the second-smallest population, it is the state with the second-highest popu ...

, the westernmost federal state of

Austria Austria, formally the Republic of Austria, is a landlocked country in Central Europe, lying in the Eastern Alps. It is a federation of nine Federal states of Austria, states, of which the capital Vienna is the List of largest cities in Aust ...

, * The State Savings Bank Building, in

City of Sydney The City of Sydney is the Local government in Australia, local government area covering the Sydney central business district and surrounding inner city suburbs of the Greater Sydney, New South Wales, Australia. Established by Act of Parliament ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, * The Temple Sinai, in

Oakland, California Oakland is a city in the East Bay region of the San Francisco Bay Area in the U.S. state of California. It is the county seat and most populous city in Alameda County, California, Alameda County, with a population of 440,646 in 2020. A major We ...

, * The Sanctuary of Vicoforte, in Italy, * BAPS Swaminarayan Akshardham (New Jersey), in Robbinsville, New Jersey.

References

External links and references

Creating elliptical domes

Elliptical domes site

Calculations

Another site for calculations

Dome calculator

More general references

Buckling of Externally Pressurized Prolate Ellipsoidal Domes

An article addressing many topics, including elliptical domes
{{Webarchive, url=https://web.archive.org/web/20201023114302/http://www.hms.civil.uminho.pt/sahc/2006/0299.pdf , date=2020-10-23
Use of elliptical domes, notably in Islamic architecture
Domes Architectural elements Ellipses

In architecture

World examples

See also

References

External links and references

Creating elliptical domes

Calculations

More general references