Dome From Wikipedia, the free encyclopedia For other uses, see Dome (disambiguation). "Domal" redirects here. For "domal consonants", see Retroflex consonant. Dome of St. Peter's Basilica in Rome crowned by a cupola. Designed primarily by Michelangelo, the dome was not completed until 1590 Fiberglass dome cottage in Davis, California. This dome was built in 1972 and is part of theBaggin's End student housing cooperative. A dome is a structural element of architecture that resembles the hollow upper half of a sphere. Dome structures made of various materials have a long architectural lineage extending into prehistory. Corbel domes and true domes have been found in the ancient Middle East in modest buildings and tombs. The construction of the first technically advanced true domes in Europe began in the Roman Architectural Revolution,[1] when they were frequently used by the Romans to shape large interior spaces of temples and public buildings, such as the Pantheon. This tradition continued unabated after the adoption of Christianity in the Byzantine (East Roman) religious and secular architecture, culminating in the revolutionary pendentive dome of the 6th century church Hagia Sophia. Squinches, the technique of making a transition from a square shaped room to a circular dome, was most likely invented by the ancient Persians. The Sassanid Empireinitiated the construction of the first large-scale domes in Persia, with such royal buildings as the Palace of Ardashir, Sarvestan and Ghal'eh Dokhtar. With the Muslim conquest of Greek-Roman Syria, the Byzantine architectural style became a major influence on Muslim societies. Indeed the use of domes as a feature of Islamic architecture has gotten its roots from Roman Greater-Syria (see Dome of the Rock). An original tradition of using multiple domes was developed in the church architecture in Russia, which had adopted Orthodox Christianity from Byzantium. Russian domes are often gilded or brightly painted, and typically have a carcass and an outer shell made of wood or metal. The onion domebecame another distinctive feature in the Russian architecture, often in combination with the tented roof. Domes in Western Europe became popular again during the Renaissance period, reaching a zenith in popularity during the early 18th century Baroque period. Reminiscent of the Roman senate, during the 19th century they became a feature of grand civic architecture. As a domestic feature the dome is less common, tending only to be a feature of the grandest houses and palaces during the Baroque period. Construction of domes in the Muslim world reached its peak during the 16th – 18th centuries, when the Ottoman, Safavid and Mughal Empires, ruling an area of the World compromising North Africa, the Middle East and South- and Central Asia, applied lofty domes to their religious buildings to create a sense of heavenly transcendence. The Sultan Ahmed Mosque, the Shah Mosque and the Badshahi Mosque are primary examples of this style of architecture. Many domes, particularly those from the Renaissance and Baroque periods of architecture, are crowned by a lantern or cupola, a Medieval innovation which not only serves to admit light and vent air, but gives an extra dimension to the decorated interior of the dome. Contents [hide] 1 Characteristics 2 History o 2.1 Early history and primitive domes o 2.2 Roman and Byzantine domes o 2.3 Chinese domes o 2.4 Arabic and Western-European domes o 2.5 Persian domes o 2.6 Russian domes o 2.7 Italian Renaissance and Ottoman domes o 2.8 South-Asian and Mughal domes o 2.9 Early modern period domes o 2.10 Modern period domes 3 Symbolism 4 Influential domes 5 General types o 5.1 Onion dome o 5.2 Corbel dome o 5.3 Geodesic dome o 5.4 Oval dome o 5.5 Parabolic dome o 5.6 Polygonal dome o 5.7 Sail dome o 5.8 Saucer dome o 5.9 Umbrella dome 6 See also 7 References 8 Gallery [edit]Characteristics Comparison of a generic "true" arch (left) and a corbel arch (right). A dome can be thought of as an arch which has been rotated around its central vertical axis. Thus domes, like arches, have a great deal of structural strength when properly built and can span large open spaces without interior supports. Corbel domes achieve their shape by extending each horizontal layer of stones inward slightly farther than the previous, lower, one until they meet at the top. These are sometimes called false domes. True, or real, domes are formed with increasingly inward-angled layers of voussoirs which have ultimately turned 90 degrees from the base of the dome to the top. A compound dome (red) with pendentives (yellow) from a sphere of greater radius than the dome. When the base of the dome does not match the plan of the supporting walls beneath it (for example, a circular dome on a square bay), techniques are employed to transition between the two. The simplest technique is to use diagonal lintelsacross the corners of the walls to create an octagonal base. Another is to use arches called squinchs to span the corners, which can support more weight. The invention of pendentives superseded the squinch technique.[2] Pendentives are triangular sections of a sphere used to transition from the flat surfaces of supporting walls to the round base of a dome. Domes can be divided into two kinds: simple and compound, depending on the use of pendentives.[3] In the case of the simple dome, the pendentives are part of the same sphere as the dome itself; however, such domes are rare.[4] In the case of the more common compound dome, the pendentives are part of the surface of a larger sphere below that of the dome itself and form a circular base for either the dome or a drum section.[3] Drums, also called tholobates or tambours, are cylindrical or polygonal walls supporting a dome which may contain windows. Domes have been constructed from a wide variety of building materials over the centuries: from mud to stone, wood, brick, concrete, metal, glass and plastic. [edit]History [edit]Early history and primitive domes Apache wigwam, by Edward S. Curtis, 1903 Cultures from pre-history to modern times constructed domed dwellings using local materials. Although it is not known when the first dome was created, sporadic examples of early domed structures have been discovered. The earliest discovered may be four small dwellings made of Mammoth tusks and bones. The first was found by a farmer in Mezhirich, Ukraine, in 1965 while he was digging in his cellar and archaeologists unearthed three more.[5] They date from 19,280 - 11,700 BC.[6] In modern times, the creation of relatively simple dome-like structures has been documented among various indigenous peoples around the world. The Wigwamwas made by Native Americans using arched branches or poles covered with grass or hides. The Efé people of central Africa construct similar structures, using leaves as shingles.[7] Another example is the Igloo, a shelter built from blocks of compact snow and used by the Inuit people, among others. The Himba people ofNamibia construct "desert igloos" of wattle and daub for use as temporary shelters at seasonal cattle camps, and as permanent homes by the poor.[8] Drawing of an Assyrian bas-relief from Nimrud showing domed structures The historical development from structures like these to more sophisticated domes is not well documented. That the dome was known to early Mesopotamia may explain the existence of domes in both China and the West in the first millennium BC.[9] Another explanation, however, is that the use of the dome shape in construction did not have a single point of origin and was common in virtually all cultures long before domes were constructed with enduring materials.[10] The recent discoveries of seal impressions in the ancient site of Chogha Mish (c. 6800 to 3000 BC), located in the Susiana plains of Iran, show the extensive use of dome structures in mud- brick and adobe buildings.[11][12] Other examples of mud-brick buildings, which also seemed to employ the "true" dome technique have been excavated at Tell Arpachiyah, a Mesopotamian site of the Halaf (c. 6100 to 5400 BC) and Ubaid (ca. 5300 to 4000 BC) cultures.[13] Excavations at Tell al-Rimah have revealed brick domical vaults from about 2000 BC.[14] At the Sumerian Royal Cemetery of Ur, a "complete rubble dome built over a timber centring" was found among the chambers of the tombs for Meskalamdug and Puabi, dating to around 2500 BC.[15] Set in mud mortar, it was a "true dome with pendentives rounding off the angles of the square chamber." Other small domes can be inferred from the remaining ground plans, such as one in the courtyard of Ur-Nammu's ziggurat, and in later shrines and temples of the 14th century BC.[16] Corbelled beehive domes were used as granaries in Ancient Egypt from the first dynasty, in mastabas of the Old Kingdom, as pressure-relieving devices in private brick pyramids of the New Kingdom, and as kilns and cellars. Examples have been found in brick and in stone.[17] Ancient tombs have been found from Oman to Portugal with stone corbel domes. The "Hafeet graves", also called "Mezyat graves", were structures built above ground, dating to the Bronze Age period between 3200 and 2700 BC in an area straddling the borders between Oman, UAE, and Bahrain.[18][19] Similar above-ground tombs made of corbelled stone domes have been found in the fourth cataract region of Nubia with dates beginning in the second millennium BC.[20] Examples on the Mediterranean island ofSardinia have been dated to 2500 BC.