Excerpt from Modification of the Method of Mechanical Soil Analysis The mechanical analysis of the soil, as carried out in the Bureau of Soils, has been devised as an expedient method of obtaining a quantitative statement for the classification of soils on a physical basis. There exists a close relationship between the mechanical com position and most of the physical' properties of soils, although the exact nature of the relationship is not. Yet. Satisfactorily known. Many attempts have been made to classify soils upon the basis of some physical property, but to measure any physical property of soils without regard to the mechanical composition would disregard those relations of most importance in the practical management of soils. The physical properties of a soil are dependent upon the structure of the soil as well as upon the mechanical composition. The organic matter present influences both composition and structure. Hence we have a number of dependent variables of whose relations. To one another we yet know very little. But the mechanical composition of any particular soil remains reasonably constant, so that, it has been adopted as a basis for classification until the relationship ex isting between mechanical composition and the physical properties of the soil have become better known. The classification of soils on this basis is of agricultural value, as certain obvious characteristics attach to clays, loams, sands, ietc., as classes. In the mechanical analysis the soil is divided into a number of different grades of particles, whose dimensions lie between definite limits, and the percentage by weight of each of these grades is de termined. In general, the basic methods used in mechanical analysis are separation of different size particles by sifting in the case of the larger particles, and by sedimentation (usually in water) in case of the smaller ones. Various successful modifications have been devised, based on these methods. 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.