5060 x 3372 px | 42,8 x 28,5 cm | 16,9 x 11,2 inches | 300dpi
Date de la prise de vue:
9 mars 2010
Lieu:
Birk Dale, Yorkshire Dales National Park, Yorkshire, England, United Kingdom, Europe.
Informations supplémentaires:
Limestone is a sedimentary rock composed largely of the mineral calcite (calcium carbonate: CaCO3). The Romans developed the burning of limestone to make lime for use in building as a mortar, although there is little evidence of their kilns in the country. During the Middle Ages, with the increase in building, the demand for lime again increased. However until the middle of the eighteenth century most lime kilns were temporary structures near to the site where the lime was required. These were either left to collapse after use or dismantled. Lime has long been an important material in the Cumbrian Fells and Yorkshire Dales. Apart from its use to bind and render stonework and decorate walls, it has been invaluable for improving the fertility of acidic soils. Limestone was burnt in kilns wherever fuel and raw limestone could be brought together easily. Burning limestone, which is calcium carbonate, gives you quick lime, calcium oxide. Mixed with water this produces slaked lime, calcium hydroxide. When slaked lime or quick lime was added to the land it raised its pH and so improved its fertility. Slaked lime was also used as lime putty for building. This is soft when first mixed, but with time absorbs carbon dioxide from the atmosphere and hardens as it reverts back to calcium limestone. Lime kilns were used from medieval periods right through to the 18th and 19th centuries. They were used in earlier times for the production of mortar for building purposes, and sometimes, as during the 18th and 19th centuries, for the production of lime for agricultural purposes.
