Slowly at first the eddying current carried one end of the log away from its pier.

Then the edge of the main current caught at it, viciously--and so suddenly that Miki almost lost his precarious footing, the log gave a twist, righted itself, and began, to scud down stream at a speed that would have made Challoner hug his breath had he been in their position with his faithful canoe.
In fact, Challoner was at this very moment portaging the rapids below the waterfall.

To have set his canoe in them where Miki and Neewa were gloriously sailing he would have considered an inexcusable hazard, and as a matter of safety he was losing the better part of a couple of hours by packing his outfit through the forest to a point half a mile below.

That half mile was to the cub and the pup a show which was destined to live in their memories for as long as they were alive.
They were facing each other about amidships of the log, Neewa flattened tight, his sharp claws dug in like hooks, and his little brown eyes half starting from his head.

It would have taken a crowbar to wrench him from the log.