Note 10 — RAW MATERIALS; COLLECTION, AND PREPARATION

Stevenson (1883, p. 329) says: “With this (clay), 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.” And again: “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” (1883, p. 331). Binns, in “The Potter’s Craft”, describing the preparation of clay, says, “If the clay prove very sandy it must be washed, ... but all the sand should not be removed. Clay with no sand in it will be apt to crack in drying and burning. Clay with too much sand will be short and brittle in working. If the clay is very smooth and shows no sand, a little fine builder’s sand may be added with advantage, a definite proportion being used and recorded” (1910, p. 40).