Cane is a very tough fibrous material similar to grass and bamboo. The earliest way to crush the cane in the Americas for commercial production of sugar was with an animal mill with its toller acting as a wheel and rollin gover the canes. This was replaced in 1550 with animal mills of the form you see here. There were far more efficient. Two or four horses, bullocks, oxen or other draft animals walked around in a circle at the end of the arms above turing the geared rollers. A enslaved person would stand on one side of the mill and take cane stalks from a pile brought by donkey cart, and feed the cane between the center roller and the outside roller turing away from him. This would break the cane's structure. It could also destroy a slave's hand or arm, so a machete was kept near by to cut off the mangled arm when accidents happened. Another slave, standing on the other side of the mill would guide the crushed canes back between the central roller and the other outside roller, where the juice would be pressed out of the cane.