[Illustration: FIG. 531.--Secondary form, in the mold.]

[Illustration: FIG. 532.--Scrapers of gourd and earthenware for
smoothing pottery.]

[Illustration: FIG. 533.--Finished form of vessel in mold, showing
amount of contraction in drying.]

The sand had prevented contact with the basket which would have caused
the clay vessel to crack as the latter was very thin. This process
exists in full force to-day with the Oraibes in the modeling of
convex-bottomed vessels, and the Zuñis thus make their large bowls and
huge drum-jars.

Upon the bottoms of many jars of these forms, I have observed the
impressions of the wicker bowls in which they had been molded--not
entirely to be removed, it seems, by the most assiduous smoothing
before burning; for, however smooth any exceptional specimen may
appear, a squeeze in plaster will still reveal traces of these
impressions.

[Illustration: FIG. 534.--Profile of olla, or modern water-jug.]

A characteristic of these older forms of the water-jar is that they
are invariably flat or round-bottomed, while more recent and all
modern types of the olla (see Fig. 534) are concave or hollowed at the
base (see Fig. 535) to facilitate balancing on the head. Outside of
this concavity and entirely surrounding it (Fig. 536, _a_) is often to
be observed an indentation (see Fig. 536, _b_) usually slight although
sometimes pronounced.