Parchment is a writing material made from specially prepared untanned skins of animals—primarily sheep, calves, and goats. It has been used as a writing medium for over two millennia. Vellum is a finer quality parchment made from the skins of young animals such as lambs and young calves.
A spandrel is a roughly triangular space, usually found in pairs, between the top of an arch and a rectangular frame; between the tops of two adjacent arches or one of the four spaces between a circle within a square. They are frequently filled with decorative elements.
A seal is a device for making an impression in wax, clay, paper, or some other medium, including an embossment on paper, and is also the impression thus made. The original purpose was to authenticate a document, or to prevent interference with a package or envelope by applying a seal which had to be broken to open the container.
Hagia Sophia, officially the Holy Hagia Sophia Grand Mosque, and formerly the Church of Hagia Sophia and formerly museum is a Late Antique place of worship in Istanbul, designed by the Greek geometers Isidore of Miletus and Anthemius of Tralles. Built in 537 as the patriarchal cathedral of the imperial capital of Constantinople, it was the largest Christian church of the eastern Roman Empire and the Eastern Orthodox Church, except during the Latin Empire from 1204 to 1261, when it became the city's Latin Catholic cathedral. In 1453, after the Fall of Constantinople to the Ottoman Empire, it was converted into a mosque. In 1935, under the direction of Mustafa Kemal Atatürk, the secular Republic of Turkey established it as a museum. In 2020, under the direction of Recep Tayyip Erdoğan, it re-opened as a mosque.
An arch is a vertical curved structure that spans an elevated space and may or may not support the weight above it, or in case of a horizontal arch like an arch dam, the hydrostatic pressure against it.
A dome is an architectural element similar to the hollow upper half of a sphere. There is significant overlap with the term cupola, which may also refer to a dome or a structure on top of a dome. The precise definition of a dome has been a matter of controversy and there are a wide variety of forms and specialized terms to describe them.
Roman bridges, built by ancient Romans, were the first large and lasting bridges built. Roman bridges were built with stone and had the arch as the basic structure. Most utilized concrete as well, which the Romans were the first to use for bridges.
In architecture, a pendentive is a constructional device permitting the placing of a circular dome over a square room or of 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 a 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.
Gazi Husrev-beg Mosque is a mosque in the city of Sarajevo, Bosnia and Herzegovina. Built in the 16th century, it is the largest historical mosque in Bosnia and Herzegovina and one of the most representative Ottoman structures in the Balkans. Being the central Sarajevo's mosque since the days of its construction, today it also serves as the main congregational mosque of the Islamic Community of Bosnia and Herzegovina. It is located in the Baščaršija neighborhood in the Stari Grad municipality and, being one of the main architectural monuments in the town, is regularly visited by tourists.
In architecture, a squinch is a construction filling in the upper angles of a square room so as to form a base to receive an octagonal or spherical dome. Another solution to this structural problem was provided by the pendentive.
Centring, centre, centering, or center is a type of formwork: the temporary structure upon which the stones of an arch or vault are laid during construction. Until the keystone is inserted an arch has no strength and needs the centring to keep the voussoirs in their correct relative positions. A simple centring without a truss is called a common centring. A cross piece connecting centring frames is called a lag or bolst.
In architecture, a vault is a self-supporting arched form, usually of stone or brick, serving to cover a space with a ceiling or roof. As in building an arch, a temporary support is needed while rings of voussoirs are constructed and the rings placed in position. Until the topmost voussoir, the keystone, is positioned, the vault is not self-supporting. Where timber is easily obtained, this temporary support is provided by centering consisting of a framed truss with a semicircular or segmental head, which supports the voussoirs until the ring of the whole arch is completed.
Muqarnas, also known in Iranian architecture as Ahoopāy and in Iberian architecture as Mocárabe, is a form of ornamented vaulting in Islamic architecture. It is the archetypal form of Islamic architecture, integral to the vernacular of Islamic buildings. The muqarnas structure originated from the squinch. Sometimes called "honeycomb vaulting" or "stalactite vaulting", the purpose of muqarnas is to create a smooth, decorative zone of transition in an otherwise bare, structural space. This structure gives the ability to distinguish between the main parts of a building, and serve as a transition from the walls of a room into a domed ceiling.
A conical roof or cone roof is a cone-shaped roof that is circular at its base and terminates in a point.
Cultures from pre-history to modern times constructed domed dwellings using local materials. Although it is not known when or where the first dome was created, sporadic examples of early domed structures have been discovered. Brick domes from the ancient Near East and corbelled stone domes have been found from the Middle East to Western Europe. These may indicate a common source or multiple independent traditions. A variety of materials have been used, including wood, mudbrick, or fabric. Indigenous peoples around the world produce similar structures today.
Domes were a characteristic element of the architecture of Ancient Rome and of its medieval continuation, the Byzantine Empire. They had widespread influence on contemporary and later styles, from Russian and Ottoman architecture to the Italian Renaissance and modern revivals. The domes were customarily hemispherical, although octagonal and segmented shapes are also known, and they developed in form, use, and structure over the centuries. Early examples rested directly on the rotunda walls of round rooms and featured a central oculus for ventilation and light. Pendentives became common in the Byzantine period, provided support for domes over square spaces.
The early domes of the Middle Ages, particularly in those areas recently under Byzantine control, were an extension of earlier Roman architecture. The domed church architecture of Italy from the sixth to the eighth centuries followed that of the Byzantine provinces and, although this influence diminishes under Charlemagne, it continued on in Venice, Southern Italy, and Sicily. Charlemagne's Palatine Chapel is a notable exception, being influenced by Byzantine models from Ravenna and Constantinople. The Dome of the Rock, an Umayyad Muslim religious shrine built in Jerusalem, was designed similarly to nearby Byzantine martyria and Christian churches. Domes were also built as part of Muslim palaces, throne halls, pavilions, and baths, and blended elements of both Byzantine and Persian architecture, using both pendentives and squinches. The origin of the crossed-arch dome type is debated, but the earliest known example is from the tenth century at the Great Mosque of Córdoba. In Egypt, a "keel" shaped dome profile was characteristic of Fatimid architecture. The use of squinches became widespread in the Islamic world by the tenth and eleventh centuries. Bulbous domes were used to cover large buildings in Syria after the eleventh century, following an architectural revival there, and the present shape of the Dome of the Rock's dome likely dates from this time.
Italian Renaissance domes were designed during the Renaissance period of the fifteenth and sixteenth centuries in Italy. Beginning in Florence, the style spread to Rome and Venice and made the combination of dome, drum, and barrel vaults standard structural forms.
Domes built in the 16th, 17th, and 18th centuries relied primarily on empirical techniques and oral traditions rather than the architectural treatises of the time, but the study of dome structures changed radically due to developments in mathematics and the study of statics. Analytical approaches were developed and the ideal shape for a dome was debated, but these approaches were often considered too theoretical to be used in construction.
This glossary of structural engineering terms pertains specifically to structural engineering and its sub-disciplines. Please see glossary of engineering for a broad overview of the major concepts of engineering.
