Excerpt from Miscellaneous Papers on Forestry From Annual Report, Department of Agriculture for 1896
If these folds, or ridges and mountains, did not exist, the earth's surface would be a monotonous plain, practically. Everywhere equally distant from the centre of the earth, ... except in so far as that dis tance was modified by the differences between the polar and the equatorial diameters of the earth. Our streams would ¿ow slowly in the Northern hemisphere toward the northeast, and in the South ern hemisphere toward the southeast, and the large masses of water would gravitate to the poles, as those would be the portions of the earth least remote from the earth's centre. The continental land masses would tend to be in the equatorial diameter of the globe because the land there would be the highest, i. E., most distant from the earth's centre.
The introduction, however, of these shrinkage folds, which we now recognize as mountains, completely changes these relations. Water will ¿ow downward along the lines of least resistance, and as it ¿ows will wear away the soil first and the rock next, in exact proportion, other things being equal, to the rapidity of its ¿ow. We see this in the washes on our hillsides and in the constantly changing courses of our stream channels. But other things are not equal. If they were, the tendency to the formation of ravines and gulches, by erosion, would not exist, and everywhere over an equal slope the wearing away of the soil would proceed evenly, and the unbroken character of the country would in great measure be preserved, or more properly speaking, the tendency to an even reduction of our mountains would everywhere exist.
As it is, vast discrepancies in the character of soils and rocks occur; some yielding to erosion by ¿owing water more easily than others - and it is along such lines of least resistance that currents of equal velocity carve out their valley channels to the ocean, following, of course (in most instances) the trend of the larger valleys made by the folds in the earth's crust.
About the Publisher
Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com
This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
Hvis denne bog ikke er noget for dig, kan du benytte kategorierne nedenfor til at finde andre titler. Klik på en kategori for at se lignende bøger.