At each of these couriers are stationed, men trained to run at great speed, and these carry the dispatches from post to post, at the rate of eight or nine miles an hour." "But the messages must get changed, where they have to be given so often ?" "Not at all," he said.

"The couriers know nothing of the dispatches they carry." "Oh, they are written dispatches ?" Roger said.

"Then you possess the art of writing ?" "Writing, what is writing ?" the merchant asked.
"Letters are inscribed on paper," Roger said, "so that the person receiving them at a distance understands exactly what the one who wrote wished to say." The merchant shook his head.
"I know nothing of what you call letters," he said.

"We draw pictures, on a fabric formed of prepared skins, or of a composition of silk and gum, but chiefly on a paper prepared from the leaves of the aloe.

Besides the pictures there are marks, which are understood to represent certain things.