and that, amongst the edifices of the great temple,
a tezca-tlachtli=obsidian-mirror-observatory, is described. I shall
demonstrate more fully, on another occasion, that the chief purpose of
these enclosures was to serve as astronomical observatories. Dr. Brinton,
Senor Troncoso and other authorities have already observed that the game
of ball itself was intended to represent the idea of the perpetual motion
of the heavenly bodies. (See American Hero-myths, p. 119.)

Returning to reexamine the divine title Tezcatlipoca we see that, when
interpreted as "the lord of the shining obsidian mirror," it was the most
appropriate title of the lord of the Nocturnal Heaven, which myriads of
mirrors reflected each night, throughout the land. It is easy to see how
the habit of referring to the Temple Minor, in order to ascertain the
positions of the stars, would naturally lead to its being consulted more
extensively as an oracle later on. We thus clearly perceive how the lord
of the Night, whose priests called themselves "the sons of the Night,"
became intimately associated with divination and how the idea of a
definite connection between the movements of the stars or human destinies
would, in the lapse of centuries, make a deep and indelible impression
upon the minds of men.

If the obsidian mirror was the symbol, par excellence, of Mexican star
cult, there are evidences that the small mirror of polished pyrites was
that of the sun-cult. The latter seems to have been employed, in some way
or other, for the concentration of the rays of the sun required for the
lighting of the sacred fire, at noon, on the days of the vernal equinox
and summer solstice. As in Peru, this duty devolved upon the high priest
of the Above or the Son of the Sun, a title which undoubtedly pertained
also to the Mexican ruler, though not employed so ostentatiously as in
Peru. A keen emulation, which may almost be termed an intense rivalry,
seems to have existed between the two cults, which Sahagun even goes so
far as to designate as two religions. From a chapter of his Historia we
even learn that the entire population of Mexico was divided into two
halves who respectively belonged to one or the other religion, a fact
which naturally affected the position of the two classes of people and had
created the native ideas, of an upper and a lower class or caste which
will be further discussed.

Sahagun's informants explained to him that, when a child was born, its