A circular opening, esp. one at the crown of a dome

An area in the plane of a wall framed by an arch or vault, containing a window, painting, or sculpture

A spherical triangle forming the transition from the circular plan of a dome to the polygonal plan of its supporting structure

An arch or corbeling built acrosd the upper inside corner of a square tower to support the side of a superimposed octagonal structure

A dome built with steel or timber trusses arranged in a radial manner and connected by polygonal rings at various heights

A steel dome structure having members that follow the lines of latitude and longitude, and a third set of diagonals completing the triangulation

A steel dome structure having members that follow the lines of latitude, and two sets of diagonals replacing the lines of longitude and forming a series of isosceles triangles

A steel dome having members that follow three principal sets of great circles intersecting at 60°, subdividing to the dome surface into a series of equilateral spherical triangles

A superstructure crowning a roof or dome and having open or windowed walls to let in light and air

A light structure on a dome or roof, serving as a belfry, lantern, or belvedere

The vertical part of a cupola

The space between the inner and outer shells of a dome

A dormer window in a roof or spire

A space or gallery beneath a dome or vault in which low sounds produced at any of certain points are clearly audible at certain other distant points

A cylindrical or faceted construction, often pierced with windows, supporting a dome

The substructure supporting a dome or cupola

A strap, ring, or chain placed around a structure to secure and gold its parts together, as around the springing of a dome

A semidome or quarter-sphere vault, such as one over an apse or niche

Half a dome formed by a vertical section, such as one over a semicircular apse

A spherical dome formed by removing four segments so that it merges with its pendentives and sits on a square plan