Processing and Manufacturing Please choose one ADMINISTRATION AGRICULTURAL BUILDINGS COMMUNICATIONS CONFLICT CULTIVATION ENCLOSURES ENERGY EXTRACTION FLOODING GRAZINGS HOUSING KNOWLEDGE LEISURE MANUFACTURE PERCEPTION SETTLEMENTS TRADES Animal products Plant products Textiles Minerals Metals Lime-burning clamps near Carlops, Peebles-shire Clamps were an early means of heating limestone so as to transform it into powdered lime which could be used as a fertiliser on acid soils. The hollows were filled with alternate layers of coal and crushed limestone, lit and covered over. The slow-burning process was needed to transform the limestone into lime. The fertilising properties of lime were already known by the 17th century. Lime was also used as a building mortar; limestone was used as a 'flux' in iron smelting to help draw off impurities. By the 18th century, structures known as lime kilns were being built to burn lime in a more efficient way. Resource pack   1     2     3     4     5