Talking Knots of the Inka - ArchaeologyIncas used knotted strings to record numerical data such as census figures, warehouse inventories, and the number of taxpayers. This accounting system was called quipus. Quipus may have also been used for calendars, astronomy, battle accounts, dynasties, and even literature. Quechua, the Incan language, had few words and may have been recorded on royal quipus, which have elaborate woven symbols that hang from the main string. The controversial Naples Manuscript, believed to be written in the 1600's, contains a quipu fragment, and is entitled History and Rudiments of the Language of the Peruvians.