Note 41 — Chapter XIII

The river, after leaving the falls, flows through a deep valley, which would seem to indicate, by its peculiar trough-like character, that the bed of the stream must, at some age or another, have been considerably higher than it is at the present time, and that the river gradually cut its deep channel through the yielding pumice formation, until the great barrier of rock forming the falls was met with, since which period it has cut its lower bed some fifty feet beneath. In this lower valley the shores rise abruptly from the margin of the water to a height of from forty to sixty feet, and then merge into a series of level plateaux or terraces, which, stretching inland for some distance, are again succeeded by others of a similar kind, which, in many places, rise in regular gradations above each other, like giant steps. For miles down the valley of the river the wonderful terraced elevations, formed entirely of disintegrated pumice rock, which is everywhere rounded by the action of water, form the principal features of the country, and some of the hills which compose them are so symmetrical in form, and level and angular in outline, that they appear to have been built up by artificial means.