These were facts known to every student of American archeology and were inexplicable puzzles, mysteries as great as how the Mayas produced their wonderful sculptured monuments, how they worked the hardest of precious stones, how they accomplished many remarkable feats. But here, in Mictolan, their strange paradoxical development had gone beyond all bounds of imagination. They still used their ancient--their immeasurably ancient--system of mathematics, the vigesimal system; they still used the equally ancient calendrical system of the Tonalmatl or religious calendar, the Calendar-Round the Initial Series dates, the Long Count and the Cycles by which any date could be established within a period of five million years, and they still used the glyph writing. Had they possessed wheels, had they discovered the use of iron or steel, had they even acquired a knowledge of machinery, of chemistry, of electricity, I might not have been so greatly astonished. But they had none of these, and yet they possessed an intimate knowledge of matters undreamed of, unsuspected by any other race on earth, of matters that seemed downright uncanny, supernatural and utterly beyond belief. CHAPTER X The Gods Who Carved the Stones I HAD already noticed the gigantic size of vegetable products, and I had assumed that their size was partly, if not wholly, due to the fact that there was no darkness in the valley. In this surmise I found I was correct, but the light itself, which was the basic source of this light that so puzzled me, was most astounding. In fact, its source was also the source of everything amazing that I observed. It was radium, or at least some intensely radioactive material, which apparently existed in vast quantities in a certain section of the valley. How the people had learned to make use of this marvelous force of nature of which we know so little, I cannot say; but as will be seen, certain things that I discovered led me to believe that it had been used, for certain purposes, from the most ancient times by the Mayas--and possibly by other prehistoric American races. This was my first epochal discovery, and it explained many hitherto inexplicable matters. We had passed through the city and had wandered across the fields beyond, when, in gazing across the valley to the east, I noticed a barren, desolate area. Calling the prince’s attention to it, I asked about it. To my astonishment he replied that it was “the sacred place of the gods who cut the stones.” I felt I was on the verge of a most interesting and epochal discovery, so I started towards the spot despite the protests of Azcopil, who seemed to have a superstitious terror of the place. Itza, too, held back, evidently in fear, but neither could give a lucid or intelligent reason for his dread. The gods, or spirits (the two are synonymous in the Zutugil), were powerful, they brought illness and death upon all who invaded their domain, and though they were those