to 24 inches. The debris
scattered about the pits indicates the manner in which they are covered
with slabs of stone and sealed with mud when in use. In all the oven,
devices of the pueblos the interior is first thoroughly heated by a long
continued fire within, the structure. When the temperature is
sufficiently high the ashes and dirt are cleaned out, the articles to be
cooked inserted, and the orifices sealed. The food is often left in
these heated receptacles for 12 hours or more, and on removal it is
generally found to be very nicely cooked. Each of the pi-gummi ovens
illustrated above is provided with a tube-like orifice 3 or 4 inches in
diameter, descending obliquely from the ground level into the cavity.
Through this opening the fire is arranged and kept in order, and in this
respect it seems to be the counterpart of the smaller hole of the Zuni
dome-shaped ovens. When the principal opening, by which the vessel
containing the pi-gummi or other articles is introduced, has been
covered with a slab of stone and sealed with mud, the effect is similar
to that of the dome-shaped oven when the ground-opening or doorway is
hermetically closed.

No example of the dome-shaped oven of pre-Columbian origin has been
found among the pueblo ruins, although its prototype probably existed in
ancient times, possibly in the form of a kiln for baking a fine quality
of pottery formerly manufactured. However, the cooking pit alone,
developed to the point of the pi-gummi oven of Tusayan, may have been
the stem upon which the foreign idea was engrafted. Instances of the
complete adoption by these conservative people of a wholly foreign idea
or feature of construction are not likely to be found, as improvements
are almost universally confined to the mere modification of existing
devices. In the few instances in which more radical changes are
attempted the resulting forms bear evidence of the fact.

[Illustration: Fig. 54. Diagram showing foundation stones of a Zuni
oven.]

[Illustration: Plate LXXX. Old adobe church of Zuni.]

In Cibola the construction of a dome-shaped oven is begun by laying out
roughly a circle of flat stones as a foundation. Upon these the upper
structure is rudely built of stones laid in the mud and approximately in
the courses, though often during construction one side will be carried
considerably higher than another. The walls curve inward to an
apparently unsafe degree, but the mud mortar is often all