Page:Seven Years in South Africa v2.djvu/249

 dark green alge, singly or in clumps, some small as a pea, some of the size of an egg, lying loosely on its surface.

In a large measure this peculiar vegetation owes its existence to the perpetual fall of spray from the cataract; from every separate cascade clouds of vapour incessantly ascend to such a height that they may be seen for fifty miles away; at one moment they are so dense that they completely block out the view of anything beyond; another moment and a gust of wind will waft them all aside, and leave nothing more than a thin transparent veil; as the density of this creases or diminishes, the islands that he upon the farther side will seem alternately to recede or advance like visions in a fairy scene.

The effects at sunrise and at sunset are incomparably fine. Arched rainbows play over and amidst the vapoury wreaths, and display the brightness of their hues. The movement of the spray is attended by a suppressed hissing, which, however, is only audible when the wind carries off the deafening roar that rises from the bottom of the abyss. I do not know that it would be absolutely impossible to make one’s way through the bushy thickets to the very edge of the precipice and so to look down to the base of the cataract, but certainly it is not visible from any of the best standpoints for viewing the general scene. The incessant roar that rises from the mighty trough below fills the air for miles around with a rolling as of thunder; to hear it and not see from whence it comes never ceases to be bewildering; the seething waters before us crash against the crags; we find the ground beneath our