Inka khipu, AD 1400–1600. Nasca region, Peru. Cotton, 103 x 48 cm.
Khipu were Inka recording devices made of wool or cotton strings knotted in various ways and sometimes dyed different colors. They were composed of a primary cord from which hang secondary cords that carry the information. Khipu were used to record census reports, the movement of goods and people, historical events, and religious and military information.
Ernest Amoroso / National Museum of the American Indian