The portion of a vault by means of which the square space in the middle of a building is brought to an octagon or circle to receive a cupola.
The part of a groined vault which is supported by, and springs from, one pier or corbel.
a concave spandrel leading from the angle of two walls to the base of a circular dome; the structural means of support for a circular dome to rest on a square dome, a common Byzantine architecture
A triangular segment that transfers the weight of a dome to a square or polygonal base.
A transitional form used to move from a square base ground plan to a round area upon which a cylinder, dome, or both can be rested. It is designed by removing a circular section from a groin vault.
1. Carved triangular surface formed to support a circular dome over a square structure. 2. More specifically, a concave spandrel leading from the angle of two walls to the base of a circular dome. 3. It is one of the means by which a circular dome is supported over a square or polygonal compartment.
Curved triangular surface which makes the transition between an angle and a curve to support a dome.
The curved and sloping surfaces beneath a dome that mark the transition from the circle of the dome (or its drum) to the square of the supports.
One of the four concave, triangular shaped braces which form arches from one corner to another, when joined together at the top of a structure, for support of a dome over a square structure.
A curved support shaped like an inverted triangle, used to support a dome.
A pendentive is a constructive device permitting the placing of a circular dome over a square room or an elliptical dome over a rectangular room. The pendentives, which are triangular segments of a sphere, taper to points at the bottom and spread at the top to establish the continuous circular or elliptical base needed for the dome. In masonry the pendentives thus receive the weight of the dome, concentrating it at the four corners where it can be received by the piers beneath.
