Squinch

{{Short description|Architectural element used to support a dome}}

{{About|an architectural feature|square-inch analysis|Square-inch analysis}}

File:Odzun cupola.jpg, Armenia, early 8th century]]

In architecture, a squinch is a structural element used to support the base of a circular or octagonal dome that surmounts a square-plan chamber.Webster's Ninth New Collegiate Dictionary, 1986, p. 1145 Squinches are placed to diagonally span each upper corner where the walls meet. Constructed from masonry, they have several forms, including: a graduated series of stepped arches; a hollow, open half-cone (like a funnel) laid horizontally; or a small half-dome niche. They are designed to spread the load of a dome to the intersecting walls on which they are built. By bridging corners, they also visually transition an angular space to a round or near-circular zone.

Squinches originated in the Sassanid Empire of Ancient Persia, remaining in use across Central and West Asia into modern times. From its pre-Islamic origin, it developed into an influential structure for Islamic architecture.{{cite journal |last1=Labisi |first1=Giuseppe |title=Squinches and Semi-domes between the Late Sasanian and Early Islamic Periods |journal=Iran |date=2 July 2020 |volume=58 |issue=2 |pages=236–249 |doi=10.1080/05786967.2019.1633241}}{{multiref2|1={{cite magazine |last1=Cresswell |first1=K. A. C. |title=Persian Domes Before 1400 AD |date=January 1915 |publisher=Burlington Magazine Publications, Ltd |location=London |pages=146–155 |volume=26 |issue=142 |url=https://archive.org/details/burlingtonmagazi26londuoft/page/146/mode/2up |magazine=The Burlington Magazine for Connoisseurs |JSTOR=859853}}|2={{cite magazine |last1=Cresswell |first1=K. A. C. |title=Persian Domes Before 1400 AD: Conclusion |date=February 1915 |publisher=Burlington Magazine Publications, Ltd |location=London |pages=208–213 |volume=26 |issue=143 |url=https://archive.org/details/burlingtonmagazi26londuoft/page/208/mode/2up |JSTOR=859962 |magazine=The Burlington Magazine for Connoisseurs}}}}{{cite encyclopaedia |last1=O'Kane |first1=Bernard |author1-link=Bernard O'Kane (scholar) |title=Domes |date=15 December 1995 |publisher=Encyclopaedia Iranica Foundation |volume =VII |at=Fasc. 5, pp.{{nbsp}}479–485 |edition=Online |url=https://iranicaonline.org/articles/domes |encyclopaedia=Encyclopaedia Iranica |orig-date=Updated 27 February 2013}} Georgia and Armenia also inherited the form from the Sassanids, where squinches were widely employed in buildings of all kinds. They are heavily featured in surviving or ruined medieval Christian churches of the region.{{cite conference |last1=Khoshtaria |first1=David |title=The Squinch in the Architecture of the Caucasus |conference =Against Gravity: Building Practices in the Pre-industrial World |date=2015 |url=https://www.academia.edu/28711134/THE_SQUINCH_IN_THE_ARCHITECTURE_OF_THE_CAUCASUS}} An alternative approach to the structural problem of translating square space to round superstructure is the pendentive, much used in late Roman Empire and Byzantine architecture.{{cite conference |last1=Kula |first1=Seda |title=A Survey and Forms Catalogue for Dome and Transitional Element Usage in the Early Ottoman Architecture |conference=Domes in the World Congress, Florence March 2012 |date=January 2012 |url=https://www.academia.edu/76910387/A_Survey_and_Forms_Catalogue_for_Dome_and_Transitional_Element_Usage_in_the_Early_Ottoman_Architecture}} Domes built in the Roman-influenced world utilised separately-evolved construction methods.

File:Squinch.jpg in Fars province, Iran]]

History

= 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.{{cite encyclopaedia |last1=Huff |first1=D. |title=Architecture iii. Sasanian Period |date= 15 December 1986 |publisher=Encyclopaedia Iranica Foundation |volume =II |at=Fasc. 3, pp.{{nbsp}}329–334 |edition=Online |url=https://iranicaonline.org/articles/architecture-iii |encyclopaedia=Encyclopaedia Iranica |orig-date=Updated 11 August 2011}}{{cite journal |last1=Golzari |first1=Elaheh |last2=Rabb |first2=Péter |title=Revisiting the Geometry of the Transition Zone Using Filposh Squinches in Ardeshir Palace |journal=Építés – Építészettudomány |date=26 September 2022 |volume=50 |issue=3-4 |pages=351–364 |doi=10.1556/096.2022.00079 |url=https://akjournals.com/view/journals/096/50/3-4/article-p351.xml |language=en |issn=1588-2764}} After the rise of Islam, it remained a feature of Islamic architecture, especially in Iran, and was often covered by corbelled stalactite-like structures known as muqarnas. It was used in the Middle East and in eastern Romanesque architecture, although pendentives are more common in Byzantine architecture. The Hagia Sophia features both squinches and pendentives, in combination.

=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".{{multiref2|1={{cite dictionary |url= https://en.oxforddictionaries.com/definition/squinch |archive-url= https://web.archive.org/web/20180312083511/https://en.oxforddictionaries.com/definition/squinch |url-status= dead |archive-date= 12 March 2018 |title=squinch (1) noun |dictionary= Oxford Living Dictionaries |access-date= 11 March 2018}}|2=

{{Cite dictionary

|title =squinch, noun (Architecture)

|url = https://www.dictionary.com/browse/squinch

|dictionary = Dictionary.com

|access-date = 2015-10-24 |date = 2015}}

}}