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.