Night supervened with the suddenness of a death which has been looked for, but which is at last a surprise.  Shadow after shadow crept down the walls of the chasm, blurred its projections, darkened its faces, and crowded its recesses.  The line of sky, seen through the jagged and sinuous opening above, changed slowly to gloom and then to blackness.  There was no light in this rocky intestine of the earth except the red flicker of the camp-fire.  It fought feebly with the powers of darkness; it sent tremulous despairing flashes athwart the swift ebony river; it reached out with momentary gleams to the nearer facades of precipice; it reeled, drooped, and shuddered as if in hopeless horror.  Probably, since the world began, no other fire lighted by man had struggled against the gloom of this tremendous amphitheatre.  The darknesses were astonished at it, but they were also uncomprehending and hostile.  They refused to be dissipated, and they were victorious.

After two hours a change came upon the scene.  The moon rose, filled the upper air with its radiance, and bathed in silver the slopes of the mountains.  The narrow belt of visible sky resembled a milky way.  The light continued to descend and work miracles.  Isolated turrets, domes, and pinnacles came out in gleaming relief against the dark-blue background of the heavens.  The opposite crest of the canon shone with a broad illumination.  All the uncouth demons and monsters of the rocks awoke, glaring and blinking, to menace the voyagers in the depths below.  The contrast between this supereminent brilliancy and the sullen obscurity of the subterranean river made the latter seem more than ever like Styx or Acheron.

The travellers were awakened in the morning by the trumpetings of the cataract.  They embarked and dropped down the stream, hugging the northern rampart and watching anxiously.  Presently there was a clear sweep of a mile; the clamor now came straight up to them with redoubled vehemence; a ghost of spray arose and waved threateningly, as if forbidding further passage.  It was the roar and smoke of an artillery which had thundered for ages, and would thunder for ages to come.  It was a voice and signal which summoned reinforcements of waters, and in obedience to which the waters charged eternally.

The boat had shudders.  Every spasm jerked it onward a little faster.  It flew with a tremulous speed which was terrible.  Thurstane, a good soldier, able to obey as well as to direct, knowing that if Glover could not steer wisely no one could, sat, paddle in hand, awaiting orders.  Sweeny fidgeted, looked from one to another, looked at the mist ahead, cringed, wanted to speak, and said nothing.  Glover, working hard with his paddle, and just barely keeping the coracle bows on, peered and grinned as if he were facing a hurricane.  There was no time to have a care for sunken bowlders, reaching up to rend the thin bottom.  The one giant danger of the cataract was enough to fill the mind and bar out every minor terror.  Its deafening threats demanded the whole of the imagination.  Compared with the probability of plunging down an unknown depth into a boiling hell of waters, all other peril seemed too trifling to attract notice.  Such a fate is an enhancement of the horrors of death.