Excerpt from Minutes of Proceedings of the Institution of Civil Engineers, Vol. 120: With Other Selected and Abstracted Papers Of the thirty tunnels on the approaches, only four, of an aggre gate length of 312 yards, were originally constructed for a double track; one of 47 yards length was not widened, as the second line was taken outside the mountain; the remaining twenty-five tunnels yards) were widened and were partly lined with masonry. The material excavated (all by blasting) amounted to cubic yards, and the masonry lining amounted to cubic yards. After completing the necessary excavation, the masonry for the widening of abutments and piers and the length ening of arches was built in the usual way, with or without staging according to circumstances. Between the new and the old masonry all bond was avoided. The surface of the Old masonry, where it had to be joined by new work, was dressed ofi - the surface Of the original work being as a rule rock-faced granite thus permitting the new masonry to settle without causing cracks through its hanging on to the rough sides of the Old masonry. Several of the abutments and piers widened are very high; the Kerstelenbach pier, for instance, is 164 feet high, and shows no opening between the Old and new masonry. 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.