As soon as I began to descend to the westward it became necessary to pay strict and earnest attention to the features of the country through which I passed, in order to determine more accurately the different appearances which, as I was led to expect, the rivers would assume. In the course of my examination I found, first, that the broken country through which I travelled, was generally covered with a loose, coarse, and sandy soil; and, secondly, that the ranges were wholly deficient in that peat formation which fills the valleys, or covers the flat summits of the hills or mountains, in the northern hemisphere. The peculiar property of this formation is to retain water like a sponge; and to this property the regular and constant flow of the rivers descending from such hills, may, in a great measure, be attributed. In New South Wales on the contrary, the rains that fall upon the mountains drain rapidly through a coarse and superficial soil, and pour down their sides without a moment's interruption. The consequence is that on such occasions the rivers are subject to great and sudden rises, whereas they have scarcely water enough to support a current in ordinary seasons. At one time the traveller will find it impracticable to cross them: at another he may do so with ease; and only from the remains of debris in the branches of the trees high above, can he judge of the furious torrent they must occasionally contain. This seeming deviation on the part of Nature from her usual laws will no longer appear such, if we consider its results for a moment. The very floods which swell the rivers to overflowing, are followed by the most beneficent effects; and, rude and violent as the means are by which she accomplishes her purpose, they form, no doubt, a part of that process by which she preserves the balance of good and evil. Vast quantities of the best soil have been thus washed down from the mountains to accumulate in more accessible places. From frequent depositions, a great extent of country along the banks of every river and creek has risen high above the influence of the floods, and constitutes the richest tracts in the colony. The alluvial flats of the Nepean, the Hawkesbury, and the Hunter, are striking instances of the truth of these observations; to which the plains of O'Connell and Bathurst must be added. The only good soil upon the two latter, is in the immediate neighbourhood of the Macquarie River: but, even close to its banks, the depositions are of little depth, lying on a coarse gravelly soil, the decomposition of the nearer ranges. The former is found to diminish in thickness, according to the concavity of the valley through which the Macquarie flows, and at length becomes mixed with the coarser soil. This deposit is alone fit for agricultural purposes; but it does not necessarily follow that the distant country is unavailable since it is admitted, that the best grazing tracts are upon the secondary ranges of granite and porphyry.