one familiar with Arizona and New Mexico knows how the sudden
summer showers fill the mountain valleys with floods which flow
down upon the plain and rapidly spread out into broad, thin
sheets, often known as playas. There the water stands a short
time and then either sinks into the ground or evaporates. Such
places are favored with the best kind of natural irrigation, and
after the first shower it is an easy matter for the primitive
farmer to go out and drop grains of corn into holes punched with
a stick. Thereafter he can count on other showers to water his
field while the corn sprouts and grows to maturity. All that he
needs to do is to watch the field to protect it from the rare
depredations of wild animals. As time goes on the primitive
farmer realizes the advantage of leading the water to
particularly favorable spots and thus begins to develop a system
of artificial irrigation. In regions where such advantageous
conditions prevail, the people who live permanently in one place
succeed best, for the work that they do one year helps them the
next. They are not greatly troubled by weeds, for, though grasses
grow as well as corn in the places where the water spreads out,
the grasses take the form of little clumps which can easily be
pulled up. In the drier parts of the area of summer rain, it
becomes necessary to conserve the water supply to the utmost. The
Hopi consider sandy fields the best, for the loose sand on top
acts as a natural blanket to prevent evaporation from the
underlying layers. Sometimes in dry seasons the Hopi use
extraordinary methods to help their seeds to sprout. For
instance, they place a seed in a ball of saturated mud which they
bury beneath several inches of sand. As the sand prevents
evaporation, practically all the water is retained for the use of
the seed, which thereupon sprouts and grows some inches by the