The Work of Rain and Rivers (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1912. Excerpt: ... CHAPTER I CARVING AND CARRYING To destroy, to transport and to deposit is the work of rain and rivers. A stream, which has been running clear during prolonged fine weather, becomes turbid after heavy rain. If a glass vessel be filled from it and allowed to stand, the water becomes clean and a fine mud settles at the bottom. What is the source of the sediment? In part it may have heen removed directly from the bed of the stream, but we soon see that there is more than this could supply, and that it must have been derived from a larger area. Again, if some gravel be heaped on a pavement we see that after a heavy shower a thin film of fine earth has trespassed on the flags. In like way, all the ground sloping towards a brook or river sooner or later sends material to discolour its waters: thus we suspect, and further examination, as we shall endeavour to show, changes suspicion into conviction, that water is one of nature's carving tools, very probably the most important. In the case just mentioned its action is mechanical, but it can also B. l be chemical. In a limestone quarry which has been deserted for many years the collector of fossils generally finds old debris to be his best hunting ground. Here the fossils are often developed, that is cleared from the enveloping matrix, with a delicacy and precision, which the most skilled workman can seldom rival. Changes of temperature, which break the continuity of particles by expansion and contraction, and the wind which blows them away, may have done something, but these alone are inadequate. Another agent must have been at work, and that it is the more potent soon becomes obvious. Go where we will over a limestone district, we find its fossils have been similarly developed, while this process is much less con...