15 
plus one for the upper platform equals 3^5 J the number of days in the 
solar year. Each face of the pyramid rising in 9 terraced steps , is 
divided midway by its stairway. This results in 18 sections corresponding 
to the 18 months of the yearly Mayan calendar. On each pyramid face can 
be counted also 52 "panels,’' none too distinctly marked in the photo- 
graphs, which in number equal the number of years in the Toltec cycle, 
or phase of the Mayan civilization at the tin®. How coincidental is 
the correspondence of the number of these panels with the weeks in our 
calendar year? 
Our guide to the ruins, Felipe Castillo, called to our attention 
the fact that the stairways are actually wider at the top than at the 
bottom, a device here employed by the Maya architects to overcome the 
otherwise apparent convergence of the sides of the stairs in visual 
perspective had they been built truly parallel. This greater width 
at the top of each staircase is not apparent in frontal view. Only in 
an angle "shot" is it apparent. (Fig. ) 
The pyramid, and the temple facing north on its upper platform, are 
not precisely oriented with respect to the cardinal points of the compass. 
There is a slight deviation east of north. In the light of the known 
competence of the Maya astronomers, could it have been purposeful and 
be related to some recurring celestial phenomenon not yet correlated 
with this deviation? 
On revisiting the Castillo early the following morning, I could not 
help but notice the sharply defined triangular shadows cast by the west 
