A knotted cord was a primitive surveyor's tool for measuring distances. It is a length of cord with knots at regular intervals. They were eventually replaced by surveyor's chains, which being made of metal were less prone to stretching and thus were more accurate and consistent.
Knotted cords were used by many ancient cultures. The Greek schoenus is referred to as a rope used to measure land. Ropes generally became cables and chains with Pythagoras making the Greek agros a chain of 10 stadia equal to a nautical mile c 540 BC. The Romans used a waxed cord for measuring distances.
