It heaped itself up like a mountain, then, with a swift and dreadful motion, advanced again in one vast wave.
In an instant all that multitude were in full flight.
Hugh and Dick fled like the rest, and with them David, though whither they went they knew not.
All they knew was that the ground leapt and quivered beneath their feet, while behind them came the horrible, seething hiss of water on the crest of which men were tossed up and down like bits of floating wood..