Editing Dome (section)

== Elements ==
[[File:Cúpula de l'església de l'Assumpció de Carcaixent (Ribera Alta-País Valencià).jpg|thumb|Dome of the Church of the Assumption in [[Carcaixent]]]]
The word "[[cupola]]" is another word for "dome", and is usually used for a small dome upon a roof or [[Turret (architecture)|turret]].{{sfn|Fleming|Honour|Pevsner|1991|p=114}} "Cupola" has also been used to describe the inner side of a dome.{{sfn|Technical|1872|p=252}}{{efn|name=Parker definitions 2012b}} The top of a dome is the "crown". The inner side of a dome is called the "intrados" and the outer side is called the "extrados".{{sfn|Dumser|2010|p=436}} As with arches, the "springing" of a dome is the base level from which the dome rises and the "haunch" is the part that lies roughly halfway between the base and the top.{{sfn|Dumser|2010|p=436}}{{sfn|Fleming|Honour|Pevsner|1991|p=203}} Domes can be supported by an elliptical or circular wall called a "drum". If this structure extends to ground level, the round building may be called a "[[Rotunda (architecture)|rotunda]]".{{sfn|Curl|Wilson|2015|p=236}} Drums are also called "[[tholobate]]s" and may or may not contain windows. A "[[tambour]]" or "[[Roof lantern|lantern]]" is the equivalent structure over a dome's oculus, supporting a cupola.{{sfn|Ching|2011|p=63}}

When the base of the dome does not match the plan of the supporting walls beneath it (for example, a dome's circular base over a square [[Bay (architecture)|bay]]), techniques are employed to bridge the two.{{sfn|Fleming|Honour|Pevsner|1991|p=127}} One technique is to use corbelling, progressively projecting horizontal layers from the top of the supporting wall to the base of the dome, such as the corbelled triangles often used in Seljuk and Ottoman architecture.{{sfn|Arun|2006|pp=304–305}} The simplest technique is to use diagonal [[Lintel (architecture)|lintels]] across the corners of the walls to create an [[octagon]]al base. Another is to use arches to span the corners, which can support more weight.{{sfn|Nuttgens|1997|p=123}} A variety of these techniques use what are called "[[squinch]]es".{{sfn|Ward|1915|p=2}} A squinch can be a single arch or a set of multiple projecting nested arches placed diagonally over an internal corner.{{sfn|Fleming|Honour|Pevsner|1991|pp=127, 419}} Squinch forms also include trumpet arches, [[Niche (architecture)|niche]] heads (or half-domes),{{sfn|Ward|1915|p=2}} trumpet arches with "anteposed" arches, and muqarnas arches.{{sfn|Mediati|Colistra|Arena|2020|p=3}} Squinches transfer the weight of a dome across the gaps created by the corners and into the walls.{{sfn|Ibrāhīm|1975|p=5}} Pendentives are triangular sections of a sphere, like concave [[spandrel]]s between arches, and transition from the corners of a square bay to the circular base of a dome. The curvature of the pendentives is that of a sphere with a diameter equal to the diagonal of the square bay.{{sfn|Fleming|Honour|Pevsner|1991|pp=127, 329}} Pendentives concentrate the weight of a dome into the corners of the bay.{{sfn|Ibrāhīm|1975|p=5}}