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.