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Cob, cobb or clom (in Wales) is a natural building material made from subsoil, water, some kind of fibrous organic material (typically straw), and sometimes lime.〔Wright, Joseph. "COB(B, sb3. 1.", ''The English Dialect Dictionary, Being the Complete Vocabulary of All Dialect Words Still in Use, or Known to Have Been in Use during the Last Two Hundred Years''. London: H. Frowde;, 1898. 676-677. Print.〕 The contents of subsoil naturally varies and if it does not contain the right mixture it can be modified with sand or clay. Cob is fireproof, resistant to seismic activity, and inexpensive. It can be used to create artistic, sculptural forms and has been revived in recent years by the natural building and sustainability movements. In technical building and engineering documents such as the Uniform Building Code, cob may be referred to as an "unburned clay masonry" when used in a structural context. It might also be referred to as an "aggregate" in non-structural contexts, such as a "clay and sand aggregate" or more simply an "organic aggregate," such as where the cob is an insulating filler between post and beam construction. ==History and usage== ''Cob'' is an English term attested to around year 1600〔"cob, n2. 1." ''Oxford English Dictionary'' 2nd. ed. 2009. CD-rom.〕 for an ancient building material that has been used for building since prehistoric times. The etymology of ''cob'' and ''cobbing'' is unclear but in several tenses means to ''beat'' or ''strike'' which is how cob material is applied to a wall. Some of the oldest man-made structures in Afghanistan are composed of rammed earth and cob. Cobwork (''tabya'') was used in the Maghreb and al-Andalus in the 11th and 12th centuries and was described in detail by Ibn Khaldun in the 14th century. Cob material is known by many names including adobe,〔Rapp, George Robert. "Unbaked clay or mud", ''Archaeomineralogy''. 2nd ed. Berlin: Springer, 2009. Print.〕 lump clay,〔 puddled clay, chalk mud,〔 wichert,〔 clay daubins,〔 swish (African), torchis (French),〔Edwards, Jay Dearborn, and Nicolas Verton. "mud with straw", ''A Creole Lexicon Architecture, Landscape, People''. Baton Rouge: Louisiana State UP, 2004. Print.〕 bauge (French),〔 bousille (French mud with moss),〔 cat and clay〔("cat and clay" Websters Online Dictionary accessed March 23, 2015. )〕 Cob structures can be found in a variety of climates across the globe. European examples include: * in England, notably in the counties of Devon and Cornwall in the West Country * in the Vale of Glamorgan and Gower Peninsula in Wales * in Donegal Bay in Ulster and in Munster, South-West Ireland * in Finisterre in Brittany, where many homes have survived over 500 years and are still inhabited Many old cob buildings can be found in Africa, the Middle East, and some parts of the eastern United States. A number of cob cottages survive from mid-19th century New Zealand.〔Dozens of cob cottages are (listed on the Register ) of the New Zealand Historic Places Trust, e.g. 〕 Traditionally, English cob was made by mixing the clay-based subsoil with sand, straw and water using oxen to trample it. English soils contain varying amounts of chalk and cob made with significant amounts of chalk are called ''chalk cob'' or wychert. The earthen mixture was then ladled onto a stone foundation in courses and trodden onto the wall by workers in a process known as ''cobbing''. The construction would progress according to the time required for the prior course to dry. After drying, the walls would be trimmed and the next course built, with lintels for later openings such as doors and windows being placed as the wall takes shape. The walls of a cob house are generally about thick, and windows were correspondingly deep-set, giving the homes a characteristic internal appearance. The thick walls provided excellent thermal mass which was easy to keep warm in winter and cool in summer. Walls with a high thermal mass value act as a thermal buffer inside the home.〔 〕 The material has a long life-span even in rainy climates, provided a tall foundation and large roof overhang are present. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cob (material)」の詳細全文を読む スポンサード リンク
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