The life of Thwaite Mill began in 1641, when a weir was constructed on a natural bend in the River Aire. This weir stemmed the flow of the water and thus created a large pond; the water supply for the site’s first mill.
Little is known about this mill other than its purpose of ‘fulling’, a textiles process in which cloth was pounded in human urine (sold for a few extra pennies by the poorest in society) and then Fuller’s earth (a clay-like substance). Originally this was completed by foot, as people physically trampled the cloth in tubs, but during the Middle Ages the process was mechanised.
Huge wooden mallets known as ‘fulling stocks’ pummelled the cloth, powered by the turning of a water wheel.
Thwaite Mill had four such wheels powering eight stocks. Fulling was an important part of cloth production, as it cleaned the natural grease from newly woven threads and matted them together more tightly, producing a smooth, thick, compact fabric. Once fulled and stretched to the desired size, cloth was then suitable for dyeing or making into clothes.
Weir - a low dam built across a river.