Quadrant in architecture refers to a curve in a wall or a vaulted ceiling. Generally considered to be an arc of 90 degrees - one quarter of a circle, or a half of the more commonly seen architectural feature - a crescent

Crescent (architecture)

A crescent is an architectural structure where a number of houses, normally terraced houses, are laid out in an arc to form of a crescent shape. A famous historic crescent is the Royal Crescent in Bath, England.-See also:* Lansdown Crescent, Bath...

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The quadrant curve in architecture was a feature popularised by Palladio who used it often for the wings and colonnades which linked his classical style villas to their service wings

Servants' quarters

Servants' quarters are those parts of a building, traditionally in a private house, which contain the domestic offices and staff accommodation. From the late 17th century until the early 20th century they were a common feature in all large houses...

 and out-buildings. However, curved quadrant buildings should not be confused with the canted

Cant (architecture)

Cant is the architectural term describing part, or segment, of a facade which is at an angle to another part of the same facade. The angle breaking the facade is less than a right angle thus enabling a canted facade to be viewed as, and remain, one composition.Canted facades are a typical of, but...

 facades of Baroque

Baroque

The Baroque is a period and the style that used exaggerated motion and clear, easily interpreted detail to produce drama, tension, exuberance, and grandeur in sculpture, painting, literature, dance, and music...

 architecture or the slightly curved buildings of the era such as the Quattro Canti

Quattro Canti

Quattro Canti, officially known as Piazza Vigliena, is a Baroque square in Palermo, Sicily, southern Italy.It was laid out on the orders of the Viceroy the Duke of Maqueda between 1608-1620 by Giulio Lasso at the crossing of the two principal streets in Palermo, the Via Maqueda and the Corso...

 in Palermo

Palermo

Palermo is a city in Southern Italy, the capital of both the autonomous region of Sicily and the Province of Palermo. The city is noted for its history, culture, architecture and gastronomy, playing an important role throughout much of its existence; it is over 2,700 years old...

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The quadrant vault, a feature of Tudor architecture, is a curving interior - a continuous arc usually of brick, as seen in a tunnel

Tunnel

A tunnel is an underground passageway, completely enclosed except for openings for egress, commonly at each end.A tunnel may be for foot or vehicular road traffic, for rail traffic, or for a canal. Some tunnels are aqueducts to supply water for consumption or for hydroelectric stations or are sewers...

 - as opposed to a ribbed vault where a framework of ribs or arches supports the curves of the vault. A quadrant arch was often employed in Romanesque architecture

Romanesque architecture

Romanesque architecture is an architectural style of Medieval Europe characterised by semi-circular arches. There is no consensus for the beginning date of the Romanesque architecture, with proposals ranging from the 6th to the 10th century. It developed in the 12th century into the Gothic style,...

 to provide decorative support, as seen in the flying buttress

Flying buttress

A flying buttress is a specific form of buttressing most strongly associated with Gothic church architecture. The purpose of any buttress is to resist the lateral forces pushing a wall outwards by redirecting them to the ground...

es of Notre-Dame de Chartres built in the second half of the 12th century.

During the 18th century, the quadrant once again became a popular design shape for the terraces

Terrace (building)

A terrace is an outdoor, occupiable extension of a building above ground level. Although its physical characteristics may vary to a great degree, a terrace will generally be larger than a balcony and will have an "open-top" facing the sky...

 of smart houses in fashionable spa town

Spa town

A spa town is a town situated around a mineral spa . Patrons resorted to spas to "take the waters" for their purported health benefits. The word comes from the Belgian town Spa. In continental Europe a spa was known as a ville d'eau...

s such as Buxton

Buxton

Buxton is a spa town in Derbyshire, England. It has the highest elevation of any market town in England. Located close to the county boundary with Cheshire to the west and Staffordshire to the south, Buxton is described as "the gateway to the Peak District National Park"...

. Henry Currey's "Quadrant", built to rival the architecture of Bath, is considered one of Buxton's finest buildings.