After the first involuntary start at the discovery, he silenced his feelings, and asked how many skulls there were in the heap.

He could not, however, understand the reply, as he had not yet mastered the Aztec method of enumeration, which was a very complicated one.
Roger walked along one side of the pile, counted the number of skulls in a line, and the number of rows, and then tried to reckon how many skulls there were.

Roger was not quick at figures, although his father had tried hard to teach him to calculate rapidly, as it was necessary for one who traded, and bought and sold goods of all descriptions, to be able to keep his own figures; or he would otherwise be forced always to carry a supercargo, as was indeed the custom in almost all trading ships, for there were few masters who could read and write, far less keep accounts.
However, as he found there were a hundred skulls in each line, and ten rows, and as the heap was nearly square, it was not a difficult task to arrive at the conclusion that there must be a hundred thousand skulls in the pile.
This seemed to him beyond belief, and yet he could arrive at no other conclusion.

If a hundred thousand victims had been offered up, in one temple of this comparatively small city, what must be the total of men killed throughout the country?
The pile had, no doubt, been a long time in growing, perhaps a hundred years; but even then it would give a thousand victims, yearly, in this one temple.
Although it seemed well-nigh impossible to Roger, it was yet by no means excessive, for according to the accounts of all historians, Mexican and Spanish, the number of victims slain, annually, on the altars of Mexico amounted to from twenty-five to fifty thousand.
"The god has good reason to be pleased ?" the Aztec ambassador, who was watching Roger's face closely, remarked.
"If he is fond of blood and sacrifices, he should indeed be pleased," Roger said quietly; "but all gods do not love slaughter.
Quetzalcoatl, your god of the air, he who loved men and taught them what they know--such a god would abhor sacrifices of blood.
Offerings of fruit and flowers, which he taught men to grow, of the arts in which he instructed them, would be vastly more pleasing to him than human victims." Roger spoke in a tone of authority, as if he were sure of what he stated.
"When the white god left your shores, there were no human sacrifices offered to the gods"-- this fact Roger had learned from Malinche, who had told him that the custom had been introduced in comparatively late years.

She said ten generations, which he supposed would mean about two hundred years--"and such a custom would be abhorrent to him." The Aztec governor looked very grave.