The Lime Kilns of Cot Castle and Fairy Burn
Background of Limekilns
In Scotland limestone has been quarried and mined for many industries such as agriculture, building, paper making, stone dusting in coal mines and iron and steel manufacturers. In agriculture, the addition of lime to cultivated earth is essential to ensure the satisfactory growth of crops, as the calcium it contains is a valuable plant nutrient.
The Stonehouse seam forms an outcrop of the Carboniferous Limestone series from north‑west Glasgow, south‑eastward through East Kilbride to Lesmahagow, and thereon to Auchenheath, Crossford and Carluke.
The geological features of limestone can provide important information of the period from which it was formed, for most are comprised in origin, of organic remains, such as shell and coral. However, through metamorphism and recrystallization of the original mineral constituents, differing qualities of limestone evolve. Most limestone seams are thin and were in general reached by mining. For economic purposes the value of limestone depends greatly upon the total quantity of calcium carbonate contained within the stone.
Where the soil is deficient in lime, this can be addressed by adding some form of calcium carbonate, such as, Marl (ground limestone), burnt lime or slaked (wet) lime. Unfortunately, Marl was not cost effective, as large quantities were needed to obtain the desired effect with the soil. However, burnt or slaked lime has twice the strength, and breaks down to a finer, more applicable substance when added to the soil. During Scotland’s former coal mining industry, vast amounts of ground limestone (Marl) were used in the coal mines for diluting, or covering up fine coal dust, which was dangerous and capable of causing coal dust explosions.
In the building industry lime is used for mortar and plaster, and was produced locally where demand existed. Mixing shale with the correct amount of lime will combine to form the chemical composition of cement. Lime is also an ingredient in the paper making industry, however, the quality of the lime content is not of great importance.
Limekilns within Stonehouse