Fig. 94 also embodies two specimens of this form. The special object of this arrangement is in some cases difficult to determine; the raised end in all the examples on any one roof always takes the same direction, and in many cases its position relative to drainage suggests that it is a provision against flooding by rain on the slightly sloping roof; but this relation to drainage is by no means constant. Roof holes on the west side of the village in such positions as to be directly exposed to the violent sand storms that prevail here during certain months of the year seem in some cases to have in view protection against the flying sand. We do not meet with evidence of any fixed system to guide the disposition of this feature. In many cases these trap holes are provided with a thin slab of sandstone large enough to cover the whole opening, and used in times of rain. During fair weather these are laid on the roof, near the hole they are designed to cover, or lie tilted against the higher edge of the trap, as shown in Fig. 97. [Illustration: Fig. 97. A Zuñi roof hole with cover.] When the cover is placed on one of these holes, with a high slab at one end, it has a steep pitch, to shed water, and at the same time light and air are to some extent admitted, but it is very doubtful if this is the result of direct intention on the part of the builder. The possible development of this roof trap of unusual elevation into a rudimentary chimney has already been mentioned in the discussion of chimneys. A development in this direction would possibly be suggested by the desirability of separating the access by ladder from the inconvenient smoke hole. This must have been brought very forcibly to the attention of the Indian when, at the time a fire was burning in the fireplace, they were compelled to descend the ladder amidst the smoke and heat. [Illustration: Plate C. An excavated room at Kin-tiel.] [Illustration: Fig. 98. Kiva trapdoor in Zuñi.] The survival to the present time of such an inconvenient arrangement in the kivas can be explained only on the ground of the intense conservatism of these people in all that pertains to religion. In the small roof holes methods of construction are seen which would not be so practicable on the larger scale of the ladder holes after which they have been modeled. In these latter the sides are built up of masonry or adobe, but the framing around them is more like the usual coping over walls. The stone that, set on edge in the small openings built for the admission of light, forms a raised end never occurs in these. The ladder for access rests against the coping.