The two islands and what came of them Author:Thomas Condon Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: the origin of the rock materials, their travels, and the agencies that elevated them to their present positions, as well as to the hardening process that left th... more »em solid stone. If we travel for even a few miles along the banks of any large river just after its flood season, scarcely any fact awakens more interest than the enormous quantities of mud, sand and gravel one sees left by the flood in the quiet reaches of the stream during this period of high water. In a river bed of the magnitude of the Columbia, the quantity of this annual deposit will awaken surprise when seen at any one point of its course, but to realize its full magnitude, one must think of the whole length of the river bed bordered by these deposits, and further, that they are not stationary in any portion of the river bed, but all drifting further down stream every flood time till they reach the ocean or the lake, while fresh materials are drifting from the mountains to take their place. If, now, we would trace this stream of sediment still farther toward its fountain head, we will find fcj E its continuance in the currents of a thousand rills made turbid by rains that wash downward what last winter's frosts loosened from rocks and ledges, and that these rills converge into brooks, the brooks into creeks, the creeks. into rivers, and these into the Columbia. Such, in brief, is the course of this great flood of sediment that runs a continuous stream from the mountains to the sea. Once out at sea the current that brought it there ceases; the heavier particles drop to the bottom at the mouth of the river while the lighter and finer materials are drifted by the currents of the ocean, till the whole has found its resting place as water sediment, covering in its muddy or sandy beds whatever of shell or bone...« less