Publisher's Synopsis
Excerpt from Comparison of the Compressive Strength of Concrete Made With Limestone Screenings and With Torpedo Sand: A Thesis
Most of the railroads of Chicago are now engaged in elevating their tracks. Of course retaining walls are needed to keep the tracks of the companies within their respective rights of way, and these walls have been made of different materials. 'they were first built of rubble masonry and the abutments at right angles to the tracks, being placed on each side of street subways, of ashlar. The work on such walls was necessarily slow and expensive, as they had to be in perfect alignment and of course skilled masons were employed to build them.
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.
