The roof being finished, a floor of stone flags is laid; but this is never in a continuous level, for at one end it is raised as a platform some 10 or 12 inches high, extending for about a third of the length of the kiva and terminating in an abrupt step just before coming under the hatchway, as illustrated in the ground plan of the mungkiva of Shupaulovi (Fig. 22, and also in Figs. 25 and 27). On the edge of the platform rests the foot of a long ladder, which leans against the higher side of the hatchway, and its tapering ends project 10 or 12 feet in the air. Upon this platform the women and other visitors sit when admitted to witness any of the ceremonies observed in the kiva. The main floor in a few of the kivas is composed of roughly hewn planks, but this is a comparatively recent innovation, and is not generally deemed desirable, as the movement of the dancers on the wooden floor shakes the fetiches out of position. On the lower or main floor a shallow pit of varying dimensions, but usually about a foot square, is made for a fireplace, and is located immediately under the opening in the hatchway. The intention in raising the hatchway above the level of the roof and in elevating the ceiling in the middle is to prevent the fire from igniting them. The ordinary fuel used in the kiva is greasewood, and there are always several bundles of the shrub in its green state suspended on pegs driven in the wall of the hatchway directly over the fire. This shrub, when green, smolders and emits a dense, pungent smoke, but when perfectly dry, burns with a bright, sparkling flame. Across the end of the kiva on the main floor a ledge of masonry is built, usually about 2 feet high and 1 foot wide, which serves as a shelf for the display of fetiches and other paraphernalia during stated observances (see Fig. 22). A small, niche-like aperture is made in the middle of this ledge, and is called the katchin kihu (katchina house). During a festival certain masks are placed in it when not in use by the dancers. Some of the kivas have low ledges built along one or both sides for use as seats, and some have none, but all except two or three have the ledge at the end containing the katchina house.