opening sentence of this introduction, to look at the
familiar constellations, with a view to verifying the resemblance noted
above. As my gaze sought "the pointers" in Ursa Major, and then
mechanically turned to Polaris, I thought of some passages I had recently
re-read, in Professor Lockyer's Dawn of Astronomy, realizing that his
observations, dealing with the latitude 26 deg. (taking Thebes as representing
Egypt), could equally apply to Mexico as this country stretches from
latitude 15 deg. to 31 deg..

[Illustration.]

Figure 2

"The moment primitive man began to observe anything, he must have taken
note of the stars, and as soon as he began to talk about them he must have
started by defining, in some way or other, the particular star he
meant.... Observers would first consider the brightest stars and separate
them from the dimmer ones; they would then discuss the stars which never
set (the circumpolar constellations) and separate them from those which
did rise and set. Then they would naturally, in a northern clime, choose
out the constellation of the Great Bear or Orion, and for small groups,
the Pleiades (_op. cit._ p. 132).... A few years' observation would have
appeared to demonstrate the absolute changelessness of the places of the
rising and setting of the same stars. It is true that this result would
have been found to be erroneous when a long period of time had elapsed and
when observation became more accurate, but for hundreds of years the stars
would certainly appear to represent fixity, while the movements of the
sun, moon and planets would seem to be bound by no law ... would appear
erratic, so long as the order of their movements was not known."

The reflection that Ursa Major was probably the first constellation which
made any deep impression upon the mind of prehistoric man in America, as
elsewhere, lent an additional interest to the star-group, as I
concentrated my mind upon its form and endeavored to imagine it in four
equidistant positions, corresponding to the numerals in the symbol _Ollin_
of the calendar-stone of Mexico (fig. 2, no. 2).

I succeeded in obtaining, in succession, mental images of the
constellation in four opposite positions. This effort led to an unforeseen
result which surprised me. In a flash of mental vision I perceived a
quadrupled image of the entire constellation, standing out in
scintillating brilliancy fr