Semi-dome

A semi-dome(also called a "half-dome") is the term in architecture for half a dome.The Grove Encyclopedia of Medieval Art and Architecture, Volume 2, ed. Colum Hourihane (New York: Oxford University Press, 2012). p. 303 It is used to cover a semi-circular area, usually an apse.Illustrated Dictionary of Historic Architecture, ed. Cyril M. Harris (New York: Dover Publications, 1983), p. 485 A semi-dome was often used at each end of a barrel vaulted ceiling.'Masonry and Stone Cutting', Carpentry and Building Vol. XI, No. 4 (April 1889), p. 75 

 History 
An early use was to cover Roman cult images. They are a feature found in Ancient Roman and traditional church architecture. The semi-dome is featured in Byzantine architecture and Early Christian architecture. They are prominent in mosques and iwans in Islamic architecture. Some mosques featured semi-domes decorated with glass mosaics.Sheila D. Campbell, The Mosaics of Anemurium (Toronto: Pontifical Institute of Mediaeval Studies, 1998), p. 37 In the second half of the 6th century Ottoman architecture began using half-domes combined with domes.Andrew C. Hess, The Forgotten Frontier: A History of Sixteenth-Century Ibero-African Frontier (Chicago: University of Chicago Press, 2010), p. 203 Semi-domes were common in Roman baths, palaces and large buildings.Francis Bond, Gothic Architecture in England: An Analysis of the Origin & Development of English church Architecture from the Norman Conquest to the Dissolution of the Monasteries (London: B.T. Batsford; New York: Scribner's, 1906), p. 283 During the Dark Ages in Britain whenever an apse was built, a semi-dome covered it. In 11th century Normandy every apse of every church had a semi-dome over it. The semi-dome went out of use when the east end of churches were squared.

 References 

Category:Architectural elements