Roads were another key element of Pachacutec's program to solidify his empire. Under his reign, the Incas con-
Strutted some 2,500 miles of stone roads, many of them across high mountain passes and others through steaming swamps. Though they were extremely well built, with tightly fitted stones, these were not roads as Europeans would understand them: most were only about three feet wide, which was sufficient to accommodate travelers on foot or load-bearing llamas (YAHM-uz). The latter, a relative of the camel, constituted the Incas' principal form of pack animal, though llamas could not carry anything like the weight supported by camels.
Along with the roads, the Incas built way stations placed at intervals equal to a day's travel, so that travelers could rest and obtain supplies. Trained runners traversed the road system, keeping the emperor abreast of events throughout his empire. Compared to the slow postal system of Europe (which, like that of the Inca Empire, was only for the use of the government, not ordinary citizens), the Incas' messenger service was extraordinarily fast and efficient. to the relay runners, who could transport a message at the rate of 140 miles a day, Pachacutec's army was never caught unawares by rebellions on their borders. In addition, the emperor kept troops stationed throughout the empire, ready to go into action whenever the alert was sounded.
It is hard to understand how the Incas managed to achieve their mighty feats of organization, given their lack of a written language. In order to run a government, it is necessary to keep records, particularly of inventory or supplies. In place of written records, the Incas under Pachacutec used an ingenious system of strings in varying lengths and colors, with which they recorded numerical information. For mathematical calculations, they made use of the abacus, an early form of calculator that used movable beads strung along parallel wires within a frame.
World History
