Though he had reached the island, and was within a few yards of the falls, of which he could command a good view, yet he could not solve the problem of where the vast volume of water went.
It seemed to lose itself as it disappeared into this fissure, the opposite lip of which was only eighty feet distant.
Livingston could not comprehend this mystery, till, creeping to the edge of the abyss, he peered with awe down into a large rent extending from bank to bank of the Zambesi. The river, a stream a thousand yards broad, took this gigantic leap of a hundred feet and became suddenly compressed into a space of from fifteen to twenty yards.
Livingstone found that the entire falls are but a crack made in a hard basaltic rock. This crack extends from the right to the left bank of the river. It is then prolonged on the left bank of the stream through thirty or forty miles of hills.
Looking down into the fissure on the right of the island, he saw nothing but a dense white cloud. At the time of his visit two beautiful rainbows gave added beauty to the scene. From this dense white cloud a great jet of vapor, looking exactly like steam, mounted some two hundred or three hundred feet into the air.
As the vapor became condensed, Livingstone saw its hue change to the color of dark smoke. As it fell to the ground in a constant shower, he became wet to the skin.
The shower fell for the most part upon the opposite side of the fissure. Back a few yards from the lip stood a straight hedge of evergreen trees, whose leaves were always wet.
From the roots of these trees numberless little rills ran back into the abyss. As they flowed down the steep rocky wall the columns of ascending vapor greedily absorbed them, and mounted with them into the air.
Constantly running down the side of the fissure, yet never reaching the bottom of it, these rills were an ever-active example of the laws of condensation and vaporization in nature.
On the left of the island, Livingstone saw the water at the bottom of the fissure moving away towards the place of its escape near the left bank of the river. The walls of this gigantic crack he found to be perpendicular. The rock itself is one solid mass. On the side over which the water falls he found the edge worn off two or three feet. Pieces of the rock had fallen away, owing to the action of the water. This gave to the edge a somewhat serrated appearance.