People ran to deliver messages faster. When running with a message, to deliver it in spoken form, it is safer to do it oneself. Sending anyone else is unreliable, as the game of Chinese whispers demonstrates. So a system of writing was necessary. When writing appeared messages on stone columns communicated very well across time, but they were an inefficient method of communication across space. The system became more efficient when it was the message that travelled. People ran with the written messages, rode horses to save time. For example, the network of Persian roads in the 5th century BC made communication faster and more reliable. New men and fresh horses were available at posting stations. A message could travel the full distance of the road from Susa to Sardis (3200 km) in ten days. What helped to make communication even more efficient was the Aramaic language as a lingua franca used in Ancient Persia.