In the most common form of window in present use in Tusayan and Cibola the width usually exceeds the height. Although found often in what appear to be the older portions of the present pueblos, this shape probably does not date very far back. The windows of the ancient pueblos were sometimes square, or nearly so, when of small size, but when larger they were never distinguishable from doorways in either size or finish, and the height exceeded the width. This restriction of the width of openings was due to the exceptionally small size of the building stone made use of. Although larger stones were available, the builders had not sufficient constructive skill to successfully utilize them. The failure to utilize this material indicates a degree of ignorance of mechanical aids that at first thought seems scarcely in keeping with the massiveness of form and the high degree of finish characterizing many of the remains; but as already seen in the discussion of masonry, the latter results were attained by the patient industry of many hands, although laboring with but little of the spirit of cooperation. The narrowness of the largest doors and windows in the ancient pueblos suggests timidity on the part of the ancient builders. The apparently bolder construction of the present day, shown in the prevailing use of horizontal openings, is not due to greater constructive skill, but rather to the markedly greater carelessness of modern construction. [Illustration: Fig. 87. Diagram illustrating symmetrical arrangement of small openings in Pueblo Bonito.] The same contrast between modern and ancient practice is seen in the disposition of openings in walls. In the modern pueblos there does not seem to be any regularity or system in their introduction, while in some of the older pueblos, such as Pueblo Bonito on the Chaco, and others of the same group, the arrangement of the outer openings exhibits a certain degree of symmetry. The accompanying diagram, Fig. 87, illustrates a portion of the northern outer wall of Pueblo Bonito, in which the small windows of successive rooms, besides being uniform in size, are grouped in pairs. The degree of technical skill shown in the execution of the masonry about these openings is in keeping with the precision with which the openings themselves are placed. Pl. CV, gives a view of a portion of the wall containing these openings.