PLATE 24
a. Drying the oven site with a preliminary fire before burning the pottery. At the lower right-hand corner are an old iron grate which will later support the vessels, two iron rods to hold up the roof of the oven, and a wooden poker. Cakes of dung for the oven walls are drying in the sun against the house.
b. The vessels on the grate, and the oven wall of dung cakes begun. Small tin cans support the cakes and keep them from touching the vessels. The grate rests on stones, and split cedar kindling is placed below it on the embers of the preliminary fire.
above the ground to permit the introduction of fuel below the pottery. Such a surface is usually formed of iron rods of one kind or another. One potter built up a grate of a varied assortment of iron junk supported on tin cans and odd-shaped iron fragments. Another potter used a worn-out stove-grate supported on four half-bricks.
The vessels are then placed upon the grate in an inverted position. No attempt is made to keep them from touching one another. In fact, they are crowded together in order that the greatest possible number may be burned at once ([pl. 24], b). In firing red ware and polychrome ware only one layer of vessels is placed upon the grate. When polished black ware is to be burned, two layers may be made. The vessels in the second layer are always placed carefully between those of the bottom layer, in order that there may be free circulation of air on both the interior and exterior of all the vessels ([pl. 25], a). As a rule the larger bowls are placed in the lower layer.
The number of polychrome vessels burned at one time varies from half-a-dozen to twenty, according to the area of the grate and the size of the vessels. At one burning there were eleven pieces, eight medium-sized and three small; in another there were twenty, eight of which were medium-sized, and the other twelve very small. It is possible to burn as many as thirty-five polished black bowls at once. Some potters burn both polychrome and red pottery in the same oven; others insist that this should not be done, because red ware requires far less time and heat than does polychrome.
After the pots have been placed on the grate, pieces of split cedar six to fifteen inches long are inserted underneath it. Piñon is never used, but the potters could not explain this, saying they had never tried it. A wall-like ring of dung-cakes, placed on edge but not set as snugly together as they might be, is then built around the grate ([pl. 25], b). Small tin cans, held in place by the weight of the dung, are used to prevent the cakes from touching the vessels (pi. 24, b, shows one of these cans very clearly). Sometimes small stones and broken bricks are used in place of cans. While the ring is being completed more kindling may be added. The Zuñi oven differs from that of San Ildefonso in being built of smaller pieces of manure which are laid up horizontally instead of on edge (see [pl. 31], b, c).
The fire may now be lighted before the oven is finished, but sometimes the potters wait until the roof is nearly complete. Cedar-bark shreds are generally used to start the fire. The lighting is done through the spaces between the dung-cakes, usually at more than one place, sometimes in as many as five. No attention is paid to the wind in this process. If the fire does not start quickly enough, cloths are used to fan the flames.