of these variations appear to be related to roof
drainage. These have three sides crowned in the usual manner with coping
stones laid flat, but the fourth side is formed by setting a thin slab
on edge, as illustrated in Fig. 96.

[Illustration: Fig. 96. Zuni roof-openings, with one elevated end.]

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 Zuni 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 Zuni.]

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 pe