Untangling an Accounting Tool and an Ancient Incan Mystery

LIMA, Peru — In a dry canyon strewn with the ruins of a long-dead city, archaeologists have made a discovery they hope will help unravel one of the most tenacious mysteries of ancient Peru: how to read the knotted string records, known as khipus, kept by the Incas. At the site called Incahuasi, about 100 miles south of Lima, excavators have found, for the first time, several khipus in th…