grade
(according to Rayburn's estimate, of a trifle more than three per
cent.), the bottom of it fell away rapidly. As we reached what had been,
as we found, the foot of the lake, we discovered fresh evidence of the
enormous amount of labor that had been expended in order to make its
waters an effective engine of destruction. Far in the depths beneath us,
extending across the whole width of the valley--but here the valley had
so narrowed that it was less a valley than a canon--we saw a high and
vastly broad stone wall. It was then that we perceived fully the whole
of the devilish design, and realized the years that must have been given
to its execution. By the building of the wall the level of the lake had
been raised fully three hundred feet, and so a head of water had been
obtained strong enough to thrust out the mass of rock that had been
loosened by drilling through its centre and at its sides. It would have
been possible, also, for the rock that was to be broken away to be
greatly thinned by quarrying its open face while the water was rising
slowly after the great dam was built. Clearly, the whole work had been
planned with a calm, diabolical ingenuity that assured with absolute
certainty the accomplishment of the horrible purpose that those who
labored at it had in view. It seemed impossible, but for the proof that
we here had of it, that human hearts could have in them enough of purely
devilish cruelty to spend years in thus working out to perfection so
hideous a vengeance; and to me it seemed all the more dreadful because
of the time that had passed since this most evil deed was done.
Centuries had vanished, and the slayers--living out the few years of
their lifetime--had perished from off the earth as utterly as had the
slain; yet here the whole proof of the great crime that had been wrought
lived on in enduring stone that was like to last until the very end of
the world should come. Thus had these sinners left behind them, raised
by their own hands, a monument telling of their sin; which sin had not
even the redeeming quality of passionateness, but was slow and subtle
and cruelly cold.

We were glad to turn from sight of this place and press onward into the
canon, for such the valley now had become; and we found in the dark
shadows which enveloped us in this deep cleft between the mountains a
sombreness in keeping with the feelings in our hearts. So high above us
towered the cliffs that at their top they seem