f loose dry
earth to the bottom of the trench, a depth of 4 feet 8 inches. Below
this point the walls were less than 4 feet apart, and the space filled
with gravel, as shown in figure 33. This gravel had exactly the
appearance of that in gullies on the hills outside, and plainly dates
back to the period at which the cave was formed. The stream which
aided in the erosion, or which flowed through from some sink hole or
other outside opening, carried this gravel into the crevice.
Consequently, even if the space between the walls had been ample for
dwelling purposes, an attempt to live here when the gravel was being
carried in would result in the intending settler having his effects
washed out into the river.

[Illustration: FIG. 33.--Cross section of Fort Deposit Cave at 90
feet.]

At 93 feet the side walls confining the yellow clay narrowed to a
little less than 5 feet apart. The upper portion of the one to the
left has been eroded into a recess or cavity, forming the chamber
above mentioned. The earth on the rock floor in this recess is
nowhere more than a foot deep. A section is presented in figure 34.

At 100 feet the room came to an end. The space between the walls was
71/2 feet at the floor level and 4 feet at a depth of 4 feet. At 105
feet the nearly vertical walls were only 5 feet apart on the floor; at
112 feet the space increased to 7 feet. A section showed about a foot
of loose earth mixed with ashes; 3 feet of yellow clayey earth, rather
compact; then gravel and sand. The latter was dug into for a foot, at
which level the walls were converging and it was useless to go any
deeper. Enough was done, however, to verify the supposition that this
stratum was due to the action of running water seeking its outlet at
the mouth of the cave.

At 103 feet, at the bottom of the yellow clay and on top of the
gravel, was a chalcedony pebble about 21/2 inches in diameter. The
material is foreign to this locality. It had plainly been used as a
hammer stone, and is the only object of human origin found anywhere
below the dark earth. There was not the slightest evidence of any
disturbance of the clay in which it rested.

[Illustration: FIG. 34.--Cross section of Fort Deposit Cave at 93
feet.]

At 120 feet the side walls were only 5 feet apart. At 125 feet they
again diverged slightly, and a recess on the left forms a chamber 12
feet across. At 150 feet they had drawn in to 8 feet at the widest
interval. A section