The roar became deafening.

Looking forward Isaac saw that they were entering a dark gorge.

In another moment the canoe pitched over a fall and shot between two high, rocky bluffs.

These walls ran up almost perpendicularly two hundred feet; the space between was scarcely twenty feet wide, and the water fairly screamed as it rushed madly through its narrow passage.

In the center it was like a glancing sheet of glass, weird and dark, and was bordered on the sides by white, seething foam-capped waves which tore and dashed and leaped at their stony confines.
Though the danger was great, though Death lurked in those jagged stones and in those black waits Isaac felt no fear, he knew the strength of that arm, now rigid and again moving with lightning swiftness; he knew the power of the eye which guided them.
Once more out under the starry sky; rifts, shallows, narrows, and lake-like basins were passed swiftly.