The roadrunners were the mailmen of the Inca empire. They were allowed to run on the roads. They worked by a relay system. One roadrunner would carry a message about a mile down the road and tell it to the next roadrunner. Most messages were oral. Some were sent by a quipu, the knotted language of the Inca. To the Inca, quipu means knot. The quipu is a series of colored knotted strings of wool, each tied to a main string. The type of knot, the placement of the knot, and the color of the string each had meaning to the Incas. This was a way of sending a message without the messenger understanding what was being said. As long as the person receiving the quipu understood the code in the message, it was an extremely private way to communicate.
Mostly, these
knotted strings were used by specialized workers, the record
keepers, to keep
track of the wealth of the empire – how much gold, how much
silver, how many people were in a farming community for tax
purposes. Historians believe this record system was based on the
number 10 – 1, 10, 100, and so on.
Not many people in the empire could read a quipu. Those
specialized workers who could were called rememberers.