e visionary enchantment that
surrounds us. In the midst of this fantastic scenery are vast ranges of
walls, which seem the productions of art, so regular is the workmanship.
They rise perpendicularly from the river, sometimes to the height of
one hundred feet, varying in thickness from one to twelve feet, being
equally broad at the top as below. The stones of which they are formed
are black, thick, and durable, composed of a large portion of
earth, intermixed and cemented with a small quantity of sand, and a
considerable proportion of talc or quartz. These stones are almost
invariably parallelopipeds of unequal sizes in the wall, but equally
deep, and laid regularly in ranges over each other like bricks, each
breaking and covering the interstice of the two on which it rests.
But, though the perpendicular interstice be destroyed, the horizontal
one extends entirely through the whole work. The stones, too, are
proportioned to the thickness of the wall in which they are employed,
being largest in the thickest walls. The thinner walls are composed of
a single depth of the parallelopiped, while the thicker ones consist
of two or more depths. These walls pass the river at several places,
rising from the water's edge much above the sandstone bluffs, which they
seem to penetrate; thence they cross in a straight line, on either side
of the river, the plains, over which they tower to the height of from
ten to seventy feet, until they lose themselves in the second range of
hills. Sometimes they run parallel in several ranges near to each other,
sometimes intersect each other at right angles, and have the appearance
of walls of ancient houses or gardens.

[After advancing some distance farther, the proper course to
pursue became doubtful, and Captains Lewis and Clarke set out in
different directions with exploring parties. Lewis's journey
proved an adventurous one.]

In passing along the side of a bluff at a narrow pass, thirty yards in
length, Captain Lewis slipped, and, but for a fortunate recovery by
means of his spontoon, would have been precipitated into the river over
a precipice of about ninety feet. He had just reached a spot where, by
the assistance of his spontoon, he could stand with tolerable safety,
when he heard a voice behind him cry out, "Good God, captain, what shall
I do?" He turned instantly, and found it was Windsor, who had lost his
foothold about the middle of the narrow pass, and had slip