Ledgers of Rope

Picture a string, lying across.

There are more strings tied to it, stretched toward you.

Each of these strings has a knot.

Knots to count who owes who what, who got what, and who lost the most.

These were the Quipu that ran the Incan Empire.

In 1533, as Pizarro's men looted an Inca storehouse, they watched as a native keeper recorded their theft using knots on strings.