The sorting shed at Calstock (Cotehele). Here can be seen the one of the cobbing stools, and two of the jigging machines. Balmaidans (women workers) would sit on the cobbing stool breaking up stone to approx 6mm diameter. When there was enough, about 1hudredweight (56kg) the material would be sown into sacks and placed into the jigging machines. With water flowing down the wooden water shute (the headgear IS present) the operator would move the lever up and down for about two hours. In so doing would force water through the sack and cause the wanted material to seperate out from the waste.