Within the limits of Canyon de Chelly, where the physical conditions and the character of material are essentially uniform, a considerable variation in the masonry is found, implying that some conditions other than the usual ones have influenced it. Were the masonry of one class of ruins inferior or superior throughout to that of another it might be easily explained, but variations within each class are greater than those between classes. Conditions analogous to those which prevailed in the case of Ojo Caliente and Zuñi may have governed here, or there may have been other conditions of which we now know nothing. It may be that sites originally occupied as farming shelters subsequently became regular villages, as has happened in other regions. The position of the kivas in many of the ruins suggests this. As a whole the masonry is inferior to that found in the Mancos canyon and the Chaco, and superior to that of Tusayan, but, as in Tusayan, where the masonry is sometimes very roughly constructed, the builders were well acquainted with the methods which produced the finer and better work.
The highest type of masonry in the pueblo system of architecture consists of small blocks of stone of nearly uniform size, dressed, and laid in courses, and rubbed down in situ. No attempt was made to break joints. This system requires the careful preparation of the material beforehand, and examples of it are not very common in Canyon de Chelly. As a variant we have walls composed of stones of fairly uniform size, laid with the best face out and with the interstices chinked with small spalls. The chinking is carried to such an extent in some places, as in the Chaco ruins, that the walls present the effect of a mosaic composed of small spalls. Chinking is almost a universal practice, and in some localities had passed, or was passing, from a mere
constructive to a real decorative feature. Here we have the beginning of that architecture which has been defined by Ferguson as "ornamental and ornamented construction"—in other words, of architecture as an art rather than as a craft.
The use of an exterior finish of plaster was conducive to poor masonry. Such plastering is found throughout the region, but it is much more abundant in the modern than in the ancient work. Perhaps we may find in this a suggestion of relative age; not in the use of plastering, but in its prevalence.
Pueblo masonry is composed of very small units, and the results obtained testify to the patience and industry of the builders rather than to their knowledge and skill. In fact, their knowledge of construction was far more limited than would at first sight be supposed. The marked tabular character of the stone used rendered but a small amount of preparation necessary for even the best masonry. For over 90 per cent of it there was no preparation other than the selection of material. The walls and buildings were always modified to suit the ground, never the reverse, and instances in which the site was prepared are very rare, if not indeed unknown. There are no such instances in De Chelly, where sites were often irregular, and a small amount of work would have rendered them much more desirable.
Plate LVII. Masonry in Canyon De Chelly
Plate LVII shows a type of masonry which is quite common in De Chelly. It is the west room of ruin [16], near the mouth of Del Muerto. An attempt at regularity, and possibly at decorative effect, is apparent in the use of courses of fairly uniform thickness, alternating with other courses or belts composed of small thin fragments. Beautiful examples of masonry constructed on this method occur in the Chaco ruins, but here, while the method was known, the execution was careless or faulty. Chinking with small spalls has been extensively practiced and gives the wall an appearance of smoothness and finish. A similar wall, rather better constructed, occurs at the point marked [3] on the map, and in this case the stones composing the wall were rubbed down in situ. Another wall, which occurs in the same ruin, is shown in plate LVIII. In places very large stones have been used, larger than one man could handle conveniently, but the general effect of the wall face is very good. This effect was obtained by placing the best face of the stone outward and by careful chinking.