Dome
A dome is a common structural element of architecture that resembles the hollow upper half of a sphere. Domes do not have to be perfectly spherical in cross-section, however; it is sufficient that they simply be curved surfaces. A saucer dome is a dome section of large radius that caps a space with a low dome. A variant is the Onion dome that resembles more than half of a sphere, exemplified by Saint Basil's Cathedral in Moscow.
The concave triangular sections of vaulting that provides the transition between a dome and the square base on which it is set and transfer the weight of the dome are called pendentives. A less sophisticated version of a pendentive is a squinch.
A dome can be considered as an arch which has been rotated around its vertical axis. As such, domes have a great deal of structural strength. They can be constructed of ordinary masonry, held together by friction and compressive forces.
A half-dome forms the head of an exedra or its smaller version, a niche. In Late Antiquity, the exedra developed into the apse, with separate developments in Romanesque and Byzantine practice.
Many sports stadiums are domed, especially in climates that have widely-variable summer and winter weather. The first such stadium was the Astrodome in Houston, Texas. A major improvement to the domed stadium was accomplished with the construction of SkyDome in Toronto, Ontario, the first domed stadium with a retractable roof.
Famous domes
Listed in order of their completion:
- 27 BC – The Pantheon, Rome, Italy.
- 537 – Hagia Sophia, Constantinople, Turkey.
- 691 – Dome of the Rock, Jerusalem.
- 1436 – The Duomo, Florence, Italy.
- 1502, The Tempietto, Rome, Italy.
- 1593 – St. Peter's Basilica, Rome, Italy.
- 1616 – The Blue Mosque, Istanbul, Turkey.
- 1653 – The Taj Mahal, Agra, India.
- 1708 – Les Invalides, Paris, France.
- 1708 – St Paul's Cathedral, London, England.
- 1749 – The Radcliffe Camera, Oxford, England.
- 1850s – The United States Capitol, Washington, DC, USA.
- 2000 – The Millennium Dome, London, England.
See also
Categories: Architectural elements