was the Stone Age: no metals, no
firearms, no battering rams, nor devices for throwing projectiles. A
man with a rock in his hand in the doorway of either type of dwelling
could swiftly and deftly and politely speed the parting guest with a
brickbat on his head. Similar types of pottery and shell ornament are
found in both sorts of dwellings; but I have never seen any cliff
dwellings with evidences of such religious ceremony as in the cave
houses. Perhaps the difference between cliff folk and cave folk would be
best expressed by saying that the cliff people were to ancient life what
the East Side is to us: the cave people what upper Fifth Avenue
represents. One the riff-raff, the weak, the poor, driven to the wall;
the other, the strong, the secure and defended.

You go to one section of ruins, and you come to certain definite
conclusions. Then you go on to another group of ruins; and every one of
your conclusions is reversed. For instance, what drove these races out?
What utterly extinguished their civilization so that not a vestige, not
an echo of a tradition exists of their history? Scientists go up to the
Rio Grande in New Mexico, see evidence of ancient irrigation ditches, of
receding springs and decreasing waters; and they at once
pronounce--desiccation. The earth is burning up at the rate of an inch
or two of water in a century; moisture is receding toward the Poles as
it has in Mars, till Mars is mostly arid, sun-parched desert round its
middle and ice round the Poles. Good! When you look down from the cliff
dwellings of Walnut Canyon, near Flagstaff, that explanation seems to
hold good. There certainly must have been water once at the bottom of
this rocky box-canyon. When the water sank below the level of the
springs, the people had to move out. Very well! You come on down to the
cave dwellings of the Gila. The bottom falls out of your explanation,
for there is a perpetual gush of water down these rock walls from
unfailing mountain springs. Why, then, did the race of little people
move out? What wiped them out? Why they moved in one can easily
understand. The box canyons are so narrow that half a dozen pigmy boys
deft with a sling and stones could keep out an army of enemies. The
houses were so built that a child could defend the doorway with a club;
and where the houses have long hallways and stairs as in Casa Grande,
the passages are so narrow as to compel an enemy to wiggle sideways; and
one can guess the in