When the long guyave stone is in position upon the edges of the back and front stones the fire must be so applied as to maintain the stone at a uniform temperature. This is done by frequent feeding with small bits of sage brush or other fuel. The necessity for such economy in the use of fuel has to a certain extent affected the forms of all the heating and cooking devices. Fig. 69 illustrates a Sichumovi piki stone, and Fig. 70 shows the use of the oven in connection with a cooking fireplace, a combination that is not uncommon. The latter example is from Shumopavi. The illustration shows an interesting feature in the use of a primitive andiron or boss to support the cooking pot in position above the fire. This boss is modeled from the same clay as the fireplace floor and is attached to it and forms a part of it. Mr. Stephen has collected free specimens of these primitive props which had never been attached to the floor. These were of the rudely conical form illustrated in the figure, and were made of a coarsely mixed clay thoroughly baked to a stony hardness. [Illustration: Fig. 70. Piki stone and primitive andiron in Shumopavi.] [Illustration: Plate LXXXVI. A Zuñi interior.] Chimneys and fireplaces are often found in Tusayan in the small, recessed, balcony-like rooms of the second terrace. When a deep cooking-pit is required in such a position, it is obtained by building up the sides, as in the indoor fireplaces of upper rooms. Such a fireplace is illustrated in Fig. 71. A roofed recess which usually occurs at one end of the first terrace, called “tupubi,” takes its name from the flat piki oven, the variety of fireplace generally built in these alcoves. The transfer of the fireplace from the second-story room to the corner of such a roofed-terrace alcove was easily accomplished, and probably led to the occasional use of the cooking-pit, with protecting chimney hood on the open and unsheltered roof. Fig. 72 illustrates a deep cooking-pit on an upper terrace of Walpi. In this instance the cooking pit is very massively built, and in the absence of a sheltering “tupubi” corner is effectually protected on three sides by mud-plastered stone work, the whole being capped with the usual chimneypot. The contrivance is placed conveniently near the roof hatchway of a dwelling room. [Illustration: Fig. 71. A terrace fireplace and chimney of Shumopavi.] [Illustration: Fig. 72. A terrace cooking-pit and chimney of Walpi.]