When occurring in connection with kivas, ladder holes have certain peculiarities in which they differ from the ordinary form used in dwellings. The opening in such cases is made of large size to admit dancers in costume with full paraphernalia. These, the largest roof openings to be found in Zuñi, are framed with pieces of wood. The methods of holding the pieces in place vary somewhat in minor detail. It is quite likely that recent examples, while still preserving the form and general appearance of the earlier ones, would bear evidence that the builders had used their knowledge of improved methods of joining and finishing. As may readily be seen from the illustration, Fig. 98, this framing, by the addition of a cross piece, divides the opening unequally. The smaller aperture is situated immediately above the fireplace (which conforms to the ancient type without chimney and located in the open floor of the room) and is very evidently designed to furnish an outlet to the smoke. In a chamber having no side doors or windows, or at most very small square windows, and consequently no drafts, the column of smoke and flame can often on still nights be seen rising vertically from the roof. The other portion of the opening containing the ladder is used for ingress and egress. This singular combination strongly suggests that at no very remote period one opening was used to answer both purposes, as it still does in the Tusayan kivas. It also suggests the direction in which differentiation of functions began to take place, which in the kiva was delayed and held back by the conservative religious feeling, when in the civil architecture it may have been the initial point of a development that culminated in the chimney, a development that was assisted in its later steps by suggestions from foreign sources. In the more primitively constructed examples the cross pieces seem to be simply laid on without any cutting in. The central piece is held in place by a peg set into each side piece, the weight and thrust of the ladder helping to hold it. The primitive arrangement here seen has been somewhat improved upon in some other cases, but it was not ascertained whether these were of later date or not. In the best made frames for kiva entrances the timbers are “halved” in the manner of our carpenters, the joint being additionally secured by a pin as shown in Fig. 99. The use of a frame of wood in these trapdoors dates back to a comparatively high antiquity, and is not at all a modern innovation, as one would at first be inclined to believe. Their use in so highly developed a form in the ceremonial chamber is an argument in favor of antiquity. Only two examples were discovered by Mr. L. H. Morgan in a ruined pueblo on the Animas. “One of these measured 16 by 17 inches and the other was 16 inches square. Each was formed in the floor by pieces of wood put together. The work was neatly done.”[8]