In Tusayan many of the chimneys are quite low, a single pot surmounting a masonry substructure not more than 6 inches high being quite common. As a rule, however, the builders preferred to use a series of pots. Two typical Tusayan chimneys are illustrated in Fig. 74. Most of the substructures for chimneys in this province are rudely rectangular in form, and clearly expose the rough stonework of the masonry, while in Zuñi the use of adobe generally obliterates all traces of construction. In both provinces chimneys are seen without the chimney pot. These usually occur in clusters, simply because the builder of a room or group of rooms preferred that form of chimney. Pl. CI illustrates a portion of the upper terraces of Zuñi where a number of masonry chimneys are grouped together. Those on the highest roof are principally of the rectangular form, being probably a direct development from the square roof hole. The latter is still sometimes seen with a rim rising several inches above the roof surface and formed of slabs set on edge or of ordinary masonry. These upper chimneys are often closed or covered with thin slabs of sandstone laid over them in the same manner as the roof holes that they resemble. The fireplaces to which some of them belong appear to be used for heating the rooms rather than for cooking, as they are often disused for long periods during the summer season. Pl. CI also illustrates chimneys in which pots have been used in connection with masonry bases, and also a round masonry chimney. The latter is immediately behind the single pot chimney seen in the foreground. On the extreme left of the figure is shown a chimney into which fire pots have been incorporated, the lower ones being almost concealed from view by the coating of adobe. A similar effect may be seen in the small chimney on the highest roof shown in Pl. LVIII. Pl. LXXXII shows various methods of using the chimney pots. In one case the chimney is capped with a reversed large-mouthed jar, the broken bottom serving as an outlet for the smoke. The vessel usually employed for this purpose is an ordinary black cooking pot, the bottom being burned out, or otherwise rendered unfit for household use. Other vessels are occasionally used. Pl. LXXXIII shows the use, as the crowning member of the chimney, of an ordinary water jar, with dark decorations on a white ground. A vessel very badly broken is often made to serve in chimney building by skillful use of mud and mortar. To facilitate smoke exit the upper pot is made to overlap the neck of the one below by breaking out the bottom sufficiently. The joining is not often visible, as it is usually coated with adobe. The lower pots of a series are in many cases entirely embedded in the adobe.