Final answer:
Pendentives and squinches are architectural solutions for supporting domes over square spaces, with pendentives providing a smooth, concave transitional surface and squinches offering a more angular, step-like transition. Material use and construction method vary by time and location, influenced by local resources and cultural practices.
Step-by-step explanation:
What is a Pendentive and a Squinch?
A pendentive is an architectural device used when transitioning from a rectangular base to a circular dome overhead. It allows for a smooth transition and can be recognized by its curved triangle shape that spans the corner of a room. On the other hand, a squinch is a construction solution in which arches or a series of concentric diminishing layers of masonry are built across the upper corners of a square space to carry a dome. While both serve to support a dome over a square room, they differ in functionality and design.
Unique Aspects of Pendentives and Squinches
Pendentives are unique because they allow for the placement of a round dome over a square room by smoothing out the transition between the two shapes. The construction of pendentives typically involves curved surfaces that connect the circular base of a dome with the supporting vertical walls below. This creates a spherical triangle, which is concave and can be decorated with mosaics or frescoes.
Squinches, in contrast, are more like a bridge of material between the corner of a square and the dome, usually in the form of simple arches. These are structures that lend themselves to a more angular and step-like transition from the walls to the dome.
Difference in Materials and Influence of Location
The materials for a pendentive or a squinch typically depend on the period and location of the buildings they are part of. For example, the Hagia Sophia in Istanbul, Turkey, famed for its pendentives, used brick and mortar for this feature to support its massive central dome. The use of materials and the style of construction are influenced by the local environment, resources available, technological sophistication, and cultural preferences of the time.