The clay mostly used by the Zuñians in the manufacture of pottery is a dark, bluish, carbonaceous, clayey shale found in layers usually near the tops of the mesas. Several of these elevated mesas are situated near Zuñi, from which the natives obtain this material. This carbonaceous clay is first mixed with water and then kneaded as a baker kneads dough until it reaches the proper consistency; with this, crushed volcanic lava is sometimes mixed; but the Zuñians more frequently pulverize fragments of broken pottery, which have been preserved for this purpose. This seems to prevent explosion, cracking, or fracture by rendering the paste sufficiently porous to allow the heat to pass through without injurious effect. When the clayey dough is ready to be used a sufficient quantity is rolled into a ball. The dough, if worked by a careful artist, is first tested as to its fitness for molding by putting a piece of the paste to the tongue, the sensitiveness of which is such as to detect any gritty substance or particles, when the fingers fail to do so. The ball is hollowed out with the fingers into the shape of a bowl (this form constituting the foundation for all varieties of earthenware) and assumes the desired form by the addition of strips of the clay; all traces of the addition of each strip are removed before another is added, by the use of a small trowel fashioned from a piece of gourd or fragment of pottery, the only tool employed in the manufacture of pottery.
The bottoms of old water jars and bowls form stands for the articles while being worked by the potter. The bowls are filled with sand when objects of a globular form are to be made. Although I have often watched the process, yet in no instance have I ever observed the use of a potter’s wheel, measuring instrument, or model of any kind. The makers, who are always females, depend entirely on memory and skill derived from practice to accomplish their work. The vessels when completely formed are laid in some convenient place to sun-dry. A paint or solution is then made, either of a fine white calcareous earth, consisting mainly of carbonate of lime, or of a milk-white indurated clay, almost wholly insoluble in acids, and apparently derived from decomposed feldspar with a small proportion of mica. This solution is applied to
the surface of the vessel and allowed to dry; it is then ready for the decorations.
The pigments from which the paints are derived for decorative purposes are also found in the vicinity of the mesas, and are employed by the Indians in the production of two colors, each of which varies slightly according to the intensity of heat in the process of baking, or the manner in which it is applied. One varies from a black to a blackish-brown, the other from a light brick red to a dark dull red color. The material which produces these colors is generally found in a hard, stony condition, and is ground in a small stone mortar, just as we reduce India ink for use. When the pigment is properly reduced, and mixed with water so as to form a thin solution, it is applied with brushes made of the leaves of the yucca. These brushes are made of flat pieces of the leaf, which are stripped off and bruised at one end, and are of different sizes adapted to the coarse or fine lines the artist may wish to draw. In this manner all the decorations on the pottery are produced.
The substance used in producing the black ware is a clayey brown hematite, or ferruginous indurated clay, quite hard. The material used to produce the red or brown colors is a yellowish impure clay, colored from oxide of iron; indeed it is mainly clay, but contains some sand and a very small amount of carbonate of lime. These are the principal ingredients and methods involved in the manufacture of Zuñi pottery.
The method practiced by the Zuñians in baking pottery differs somewhat from that employed by the tribes who make quantities of black and red ware. It seems to be a necessity on the part of the Zuñians to observe the greatest care in this operation. Their pottery is nearly all decorated and must be baked free from contact with the peculiar fuel used for that purpose. During the baking process it sometimes happens that a piece of the fuel, which is composed of dried manure carefully built up oven-shaped around the vessels to be baked, falls against the vessel. In every such instance a carbonized or smoky spot is left on the jar or bowl, which is regarded by the Indians as a blemish. The kiln is carefully watched until the fuel is thoroughly burnt to a white ash, when the vessels can be removed without danger of such blemishes.
The mode of manufacturing pottery adopted at the pueblos of the Rio Grande Valley is quite similar to that described as practiced by the Zuñi, Shinumo, Acoma, and Laguna Indians, but there is considerable difference in the method of decorating and polishing. Polishing is practiced chiefly by the Indians of the eastern pueblos, and but little by those of the more western region.
The pueblos of Santa Clara, Cochiti, San Juan, Tesuke, &c., manufacture large quantities of pottery for sale in addition to that made for their own use. It is in these eastern pueblos that the black polished ware is chiefly found, and it is in the production of this class of ware that the chief difference in the ceramic art between the two sections exists. The clays used in the manufacture of this ware are of the same
character as those of which the other is made; the paste is prepared in the same way, so that when the vessels are formed and ready for the kiln they are of the color of the original clay. In other words, the change to the black color is not produced in making the paste or in moulding or forming the vessel, but during the process of baking. The manner of forming the vessel is the same as with the western tribes; and when, formed it is dried in the sun in the same way; after this a solution of very fine ochre-colored clay is applied to the outside and inside near the top, or to such parts of the surface as are to be polished. While this solution thus applied is still moist, the process of polishing begins by rubbing the parts thus washed with smooth, fine-grained stones until quite dry and glossy. The parts thus rubbed still retain the original red color of the clay. The vessels are again placed in the sun and allowed to become thoroughly dry, when they are ready for baking. It is in this part of the process that the great differences in color are produced. The vessels are placed together in a heap on a level spot of ground and carefully covered over with coarsely broken dried manure obtained from the corrals. The kiln thus formed is then ignited at several points.
It is proper to add here that the clays used by the Santa Clara Indians are of a brick-red color, containing an admixture of very fine sand, which, no doubt, prevents cracking in burning, and hence dispenses with the necessity of using lava or pottery fragments, as is the custom of the Indians of the western pueblos. The burning is carried on until a sufficient degree of heat is obtained properly to bake the vessels, which still retain their original red brick color. At this juncture such of the vessels as it is desired have remain in that condition are removed from the fire and allowed to cool, when they are ready for use. Those which the artists intend to color black are allowed to remain and another application of fuel, finely pulverized, is made, completely covering and smothering the fire. This produces a dense, dark smoke, a portion of which is absorbed by the baking vessels and gives them the desired black color. It is in this manner that the black ware of these eastern pueblos is produced.