Squinch A squinch in architecture is a construction filling in the upper angles of a square room so as to form a base to receive an octagonal or spherical dome
Dome
A dome is an architectural element that resembles the hollow upper half of a sphere. The precise definition has been a matter of controversy. There are also a wide variety of forms and specialized terms to describe them. A dome can rest upon a rotunda or drum, and can be supported by colum…
What is a squinch used for?
squinch, in architecture, a piece of construction used for filling in the upper angles of a square room so as to form a proper base to receive an octagonal or spherical dome.
How do you make a squinch in architecture?
The squinch is achieved by building a short bridge across each corner of a square to transform the base of the dome into an octagon. This can either be achieved by a system of corbelling or by constructing a small arch. Pendentives: A curved triangle that connect the space between the arches and walls.
What is a squinch on a dome?
Almost all domes are on squinches (supports carried across corners to act as structural transitions to a dome). Most squinches, as in the Kairouan domes, are classical Greco-Roman niches, which transform the square room into an octagonal opening for the dome.
What are pendentives and squinches in architecture?
Ancient architects came up with two solutions that came to be known as pendentives and squinches. Pendentives and squinches are architectural supports that bridge the difference between a square room and the curved dome that rises above it. Both developed in the ancient world and although in some cases they look similar, they're very different.
What is the purpose of squinch?
A squinch is a small arch places on the inner corner of a square base and is used to connect the dome to the base, transferring some of the dome's weight to the corners.
What is a pendentive in architecture?
pendentive, in architecture, a triangular segment of a spherical surface, filling in the upper corners of a room, in order to form, at the top, a circular support for a dome.
Does the pantheon have Squinches?
The Romans were the first to truly master arched construction. A dome construction either demanded that the supporting structure is round, such as in Rome's Pantheon, or are supported on a square base by using a squinch or a pendentive. The squinch is the simpler of the two.
Does the pantheon have pendentives?
By transferring the weight to piers rather than to the wall itself, pendentive construction makes possible a lofty, unobstructed interior space... The domes of earlier, central plan buildings, like the Pantheon and Santa Costanza, spring from the circular bases of a continuous wall or arcade.
What is the purpose of a pendentive?
Pendentive is the term given to a construction element that allows a dome to be placed over square or rectangular spaces. Pendentives are triangular segments of a sphere that spread at the top and taper to points at the bottom, thereby enabling the continuous circular or elliptical base needed to support the dome.
Did the Romans use pendentives?
Although rarely used, the pendentive dome was known in 2nd century Roman architecture and possibly earlier, in funerary monuments such as the Sedia dei Diavolo and the Torracio della Secchina on the Via Nomentana. Pendentive domes would be used much more widely in the Byzantine period.
Is Hagia Sophia bigger than Pantheon?
The Hagia Sophia's original dome, which collapsed in 559, was thought to be slightly bigger in diameter but shallower than the current one, built in 563. Even so, the Hagia Sophia's dome today is 102 feet in diameter — just 40 feet smaller than the Pantheon's.
Why does the Pantheon have columns?
The columns of the Pantheon have prompted a lot of discussion because scholars believe that if the columns had only been 10 Roman feet taller, they would have allowed for continuity between the porch and intermediate block that is lacking in the current structure.
What is Muqarnas vault?
A form of decorative vaulting in Islamic architecture. In muqarnas, the surface of a vault or dome is subdivided into niche-like cells that have no load-bearing function. Also know as stalactite vaulting or honeycomb vaulting. Web resource here.
Whats an upside down dome called?
inverted dome | architecture | Britannica.
Who is interred at the Pantheon?
Among those buried in its necropolis are Voltaire, Rousseau, Victor Hugo, Émile Zola, Jean Moulin, Louis Braille, Jean Jaurès and Soufflot, its architect.
What is the top of a dome called?
crownApex: The uppermost point of a dome (also known as the 'crown'). Cupola: A small dome located on a roof or turret. Extrados: The outer curve of a dome. Haunch: Part of an arch that that lies roughly halfway between the base and the top.
Where is the Romanesque squinch?
In Italy the Romanesque squinch form is either the conical type as in the church of Sant’Ambrogio at Milan or a succession of arched rings as in the 13th-century central tower of the abbey church at Chiaravalle.
What is a pendentive arched?
Pendentive, in architecture, a triangular segment of a spherical surface, filling in the upper corners of a room, in order to form, at the top, ...
Where are squinches placed?
A squinch is a wedge that fits on the top corners of a square space. At the point where the dome's bottom edge meets the room's upper horizontal edges, four triangular-like wedges (often similar to a small bridge or arch) are placed in the corners. Think of squinches as diagonal supports constructed across corners.
When was the squinch invented?
The squinch developed in the Middle East and ancient Rome around the 5th century AD , and it was often used in early Islamic and Byzantine architecture. It solved the problem of supporting the dome but tended to have a blocky, chunky appearance. Example of a corner squinch from a tomb in New Delhi, India.
What is the difference between a pendentive and a squinch?
A squinch, the more basic of the two , is a wedge that fits into the top corner of a space. The use of four squinches turns a square into an octagon to support the dome, but they have a blocky appearance. A pendentive is more elegant, like a spherical triangle.
What is a pendentive in architecture?
Essentially, a pendentive is a spherical triangle that serves as an arch. Architects used four pendentives on the upper corners of a room, where they arched inward to meet the dome's circular base.
What is a pennant and squinch?
Pendentives and squinches are architectural supports that bridge the difference between a square room and the curved dome that rises above it. Both developed in the ancient world and although in some cases they look similar, they're very different.
What are pendentives used for?
Pendentives helped spread the development of domed architecture throughout Europe and the Middle East. Cathedrals, palaces, and other types of structures often featured domes with pendentives, sometimes decorated with paintings, mosaics or other images. Example of decorated pendentives supporting a dome in a cathedral in St. Petersburg, Russia.
What is a wedge that fits into the top corner of a space?
Both forms developed around the 5th century and were first used in Byzantine and Islamic architecture. A squinch, the more basic of the two, is a wedge that fits into the top corner of a space.
squinch
squinch1 / skwinch / • n. a straight or arched structure across an interior angle of a square tower to carry a superstructure such as a dome. squinch2 • v. [tr.] tense up the muscles of (one's eyes or face): Gina squinched her face up.
squinch
squinch (archit.) †stone cut for a scuncheon XV; support constructed across an angle XIX. Shortening of SCUNCHEON .
Squinch: Concept and construction
Straight walls are erected on a square base, a dome is placed on the top of these four walls. This means that the load is transferred from the points the dome meets the walls i.e. the centre of the wall. A heavy structure like dome needs uniform weight distribution hence the load must be transferred through the corners of the square as well.
Pendentives: Concept and construction
Though squinches solved the problem of supporting the dome they the tended to have a blocky-chunky appearance, hence a much more elegant solution- pendentive was developed by the Byzantines. It is simpler in appearance but more complex in its geometry.
Evolution of Pendentives
During the Renaissance and the Baroque the preference for domed churches, especially in Roman Catholic Europe and Latin America, gave great importance to the pendentive. Pendentives are also frequently used in Islamic architecture. They are often decorated with stalactite work or as in Iran, with delicate ribbing.
Difference between Pendentives and Squinches
An arch in each of the corners of a square base that transforms the base of the dome into an octagon and allows the dome to rest on the square base.
What is a squinch?
squinch. / ( skwɪntʃ) /. noun. a small arch, corbelling, etc, across an internal corner of a tower, used to support a superstructure such as a spireAlso called: squinch arch.
What is an arch in architecture?
noun Architecture. a small arch, corbeling, or the like, built across the interior angle between two walls, as in a square tower for supporting the side of a superimposed octagonal spire.
Overview
In architecture, a squinch is a construction filling in (or rounding off) the upper angles of a square room so as to form a base to receive an octagonal or spherical dome. Another solution to this structural problem was provided by the pendentive.
Construction
Squinches may be formed by masonry built out from the angle in corbelled courses, by filling the corner with a vise placed diagonally, or by building an arch or a number of corbelled arches diagonally across the corner.
History in the Middle East
The dome chamber in the Palace of Ardashir, the Sassanid king, in Firuzabad, Iran is the earliest surviving example of the use of the squinch, suggesting that the squinch may have been invented in Persia. After the rise of Islam, it was used in the Middle East in both eastern Romanesque and Islamic architecture. It remained a feature of Islamic architecture, especially in Iran, and was often covered by corbelled stalactite-like structures known as muqarnas.
History in Western Europe
It spread to the Romanesque architecture of western Europe, one example being the Normans' 12th-century church of San Cataldo, Palermo in Sicily. This has three domes, each supported by four doubled squinches.
Etymology
The word may possibly originate, the Oxford English Dictionary suggests, from the French word escoinson, meaning "from an angle", which became the English word "scuncheon" and then "scunch".
External links
• Media related to Squinches at Wikimedia Commons