As far as Roger could learn the distance, from the coast which they had lately been following to Mexico, was by this route about three hundred miles.
On the fifth day after the messenger had been dispatched, a courier ran into the camp, just as the caravan was about to start, and handed to the chief merchant what looked to Roger like a portfolio.
This, indeed, was something of its character.

It consisted of two thin boards, within which was a sheet of paper.

It contained a number of paintings and signs, of which Roger could make nothing, but the merchants informed him that it expressed the satisfaction of the King of Tezcuco, at the news that had been sent him of the arrival of a strange white personage in the land; that the priests would consult the auguries, and decide whether it boded well or ill for the country; and in the meantime that they were to journey on to Tepeaca, where they would be met by an envoy, charged to receive the white stranger and to conduct him to Tezcuco.
The merchants themselves were only able to gather the general contents of this picture dispatch, but the slave who had drawn the one sent forward interpreted every sign and color; for Roger found that colors, as well as signs, had their meaning.

He learned from the merchants that this picture writing was a science in itself, and that it needed years of instruction and labor to acquire it.

In every town and village there were certain persons skilled in the art, so that messages of all kinds could be sent to the capital, and orders and instructions received.