Squinch

This article is about an architectural feature. For square-inch analysis, see Square-inch analysis.

Squinches supporting a dome in Odzun Basilica, 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. ^[1] Squinches are placed to diagonally span each of the upper internal corners (vertices) where the walls meet. Constructed from masonry, they have several forms, including a graduated series of stepped arches; a hollow, open half-cone (like half of a funnel laid horizontally); or a small half-dome niche. They are designed to evenly spread the load of a dome across the intersecting walls on which it rests, thus avoiding concentrating higher structural stress on smaller load-bearing areas. By bridging corners, they also visually transition an angular space to a round or near-circular zone. ^[2]

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. ^{[3] [2] [4]} 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. ^[5] 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. ^[6] Domes built in the Roman-influenced world utilised separately-evolved construction methods. ^{[4] [7]}

Squinch in the Palace of Ardashir in Fars province, Iran

History

Western Asia

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. ^{[7] [8]} 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 Western Asia and 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

Squinch in the Baptistery of San Giovanni in Fonte, Italy

The feature spread to the Romanesque architecture of western Europe. The earliest squinch still extant in Europe is the 5th-century Baptistery of San Giovanni in Fonte, Naples. ^[9] A later example is the 12th-century Norman 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". ^[10]

See also

• History of early and simple domes
• History of Persian domes
• History of Roman and Byzantine domes
• Splayed arch, an arch with conical intrados

References

1. Webster's Ninth New Collegiate Dictionary, 1986, p. 1145
2. • Cresswell, K. A. C. (January 1915). "Persian Domes Before 1400 AD". The Burlington Magazine for Connoisseurs. Vol. 26, no. 142. London: Burlington Magazine Publications, Ltd. pp. 146–155. JSTOR   859853.
   • —— (February 1915). "Persian Domes Before 1400 AD: Conclusion". The Burlington Magazine for Connoisseurs. Vol. 26, no. 143. London: Burlington Magazine Publications, Ltd. pp. 208–213. JSTOR   859962.
3. Labisi, Giuseppe (2 July 2020). "Squinches and Semi-domes between the Late Sasanian and Early Islamic Periods". Iran. 58 (2): 236–249. doi:10.1080/05786967.2019.1633241.
4. O'Kane, Bernard (15 December 1995) [Updated 27 February 2013]. "Domes". Encyclopaedia Iranica. Vol. VII (Online ed.). Encyclopaedia Iranica Foundation. Fasc. 5, pp. 479–485.
5. Khoshtaria, David (January 2016). "The Squinch in the Architecture of the Caucasus". In Robert Ousterhout; Dorian Borbonus; Elisha Dumser (eds.). Against Gravity: Building Practices in the Pre-industrial World. Against Gravity: Building Practices in the Pre-industrial World, March 20–22, 2015; Center for Ancient Studies. University of Pennsylvania, School of Arts and Sciences.
6. Kula, Seda (January 2012). A Survey and Forms Catalogue for Dome and Transitional Element Usage in the Early Ottoman Architecture. Domes in the World Congress, Florence – March 2012.
7. Huff, D. (15 December 1986) [Updated 11 August 2011]. "Architecture iii. Sasanian Period". Encyclopaedia Iranica. Vol. II (Online ed.). Encyclopaedia Iranica Foundation. Fasc. 3, pp. 329–334.
8. Golzari, Elaheh; Rabb, Péter (26 September 2022). "Revisiting the Geometry of the Transition Zone Using Filposh Squinches in Ardeshir Palace". Építés – Építészettudomány. 50 (3–4): 351–364. doi:10.1556/096.2022.00079. ISSN   1588-2764.
9. Dalton, O. M. (1925). "The Penditive and Squinch". East Christian Art: A Survey of the Monuments (New York: Hacker Art Books; 1975 facsimile ed.). Oxford: Clarendon Press. pp. 85–87. [Ormonde Maddock Dalton]. p. 86:  ... the squinch was the earliest method employed in Armenia; and its appearance in a domed building over a square plan as far east as Chinese Turkestan (Turfan), which dates from the eighth century at latest, supports [the] ... contention that it is an indigenous Asiatic invention, employed from the first in the domed Iranian dwellinghouse, which is still erected in almost its primitive form to-day. ISBN   978-0-87817-135-4.
10. • "squinch (1) noun". Oxford Living Dictionaries. Archived from the original on 12 March 2018. Retrieved 11 March 2018.
    • "squinch, noun (Architecture)". Dictionary.com. 2015. Retrieved 24 October 2015.

Further reading

• Bier, Lionel (1986). Sarvistan: A study in early Iranian architecture. College Art Association of America by Pennsylvania State University Press. ISBN   978-0-271-00416-7.
• "Palace of Ardashir". Madain Project. Abrahamic History & Archaeology.

External links

• Media related to Squinches at Wikimedia Commons