CHAPTER ELEVEN.
A DESCENT INTO DARKNESS.
In less than a dozen paces from its entrance the chine opened into a wider space, again closing like a pair of callipers.

It was a hollow of elliptical shape--resembling an old-fashioned butterboat scooped out of the solid rock, on all sides precipitous, except at its upper end.

Here a ravine, sloping down from the summit-level above, would to the geologist at once proclaim the secret of its formation.

Not so easily explained might seem the narrow outlet to the open plain.

But one skilled in the testimony of the rocks would detect certain ferruginous veins in the sandstone that, refusing to yield to the erosion of the running stream, had stood for countless ages.
Neither Walt Wilder nor the young Kentuckian gave thought to such scientific speculations as they retreated through the narrow gap and back into the wider gorge.