Fig. 494.—Evolution of rectangular forms in primitive architecture.
All this, I need scarcely add, agrees not only with my own observations in the field but with the kind of linguistic research above recorded. It would also apparently explain the occurrence of the circular semisubterranean kí wi tsi we, or estufas. These being sacred have retained the pristine form long after the adoption of a modified type of structure for ordinary or secular purposes, according to the well known law of survival in ceremonial appurtenances.
In a majority of the lava ruins (for example those occurring near Prescott, Arizona), I have observed that the sloping sides rather than the level tops of mesa headlands have been chosen by the ancients as building-sites. Here, the rude, square type of building prevails, not, however, to the entire exclusion of the circular type, which, is represented by loosely constructed walls, always on the outskirts of the main ruins. The rectangular rooms are, as a rule, built row above row. Some of the houses in the upper rows give evidence of having overlapped others below. (See section, Fig. [495].)
FLAT AND TERRACED ROOFS DEVELOPED FROM SLOPING MESA-SITES.
We cannot fail to take notice of the indications which this brings before us.
(1) It is quite probable that the overlapping resulted from an increase in the numbers of the ancient builders relative to available area, this, as in the first instance, leading to a further massing together of the houses. (2) It suggested the employment of rafters and the formation of the flat roof, as a means of supplying a level entrance way and floor to rooms which, built above and to the rear of a first line of houses, yet extended partially over the latter. (3) This is I think the earliest form of the terrace.
