They dipped the paddles, and the canoe slid on smoothly under the clear sunlight and the frost towards the film of mist where the oily green now broke up into the mad white tumult that poured down the canon.  Then the strokes quickened, the craft lurched beneath them, and the sunlight was blotted out as they plunged into spray-filled dimness.  High through the vapour towered smooth walls of stone, and the river that rebounded from them was piled in a white track of foam midway between.  The canoe swept onwards down it apparently with the speed of a locomotive, and Seaforth, crouching in the bows, gripped his paddle with bleeding fingers that had split at the knuckles with the frost.  He watched the smooth walls whirl by him mechanically, and remembered that the canon could not last forever.  There was comfort in the reflection, because the miles would melt behind them at the pace they travelled at.  That was so long as the stream flowed straight and even, but he did not care to contemplate what would happen if it foamed over any obstacle.

For a time he saw nothing but froth and spray and flitting stone, and then the roar that came back from the towering walls swelled into a great diapason terrifying and bewildering.  Seaforth glanced over his shoulder and saw that Okanagan was dipping his paddle.

“A fall or a big rapid.  We’ve got to go through,” he said.

Seaforth swept his gaze aloft for a moment while the bewildering roar grew deafening.  Nothing that had life in it could scale the horrible smooth walls that hung over them, and through a rift in the vapour he could see a filigree of whitened pines that seemed very far away projected against the blue.  They were, he fancied, at least a thousand feet above him, and he and Okanagan alone far down in the dimness of another world with their helpless companion.  Then he nerved himself for an effort as he looked forward into the spray and vapour that whirled in denser clouds ahead.  Nothing was visible through its filmy folds, but his flesh shrank from the tumult of sound that came out of it.

“Hold her straight,” cried Okanagan, in a breathless roar, and Seaforth just heard his voice through the diapason of the river.

Then the canoe lurched beneath them, and sped faster still, plunging, rocking, rolling, while the froth beat into her, and Seaforth whirled his paddle in a frenzy.  The shrinking had gone, and he was only conscious of a curious unreasoning exaltation.  A pinnacle of rock flashed by them, there was a roar from Tom, and straining every sinew on the paddle they swung, with eyes dilated and laboured breath, sideways towards the wall of stone.  Then the froth that leapt about it swept astern, and they were going on again, faster than ever, and apparently down a declivity, the spray beating upon them and the canoe swinging her bows out of a frothing confusion.  Seaforth heard a cry behind him, but could attach no meaning to it, and whirled his paddle mechanically,