Excerpt from Report of Progress Armstrong County The question thus raised is very interesting to the syste matic geologist, in respect of the proper naming of our for mations, and would be of considerable practical importance to working geologists and mining engineers were they deal ing with coal measures beneath river level in this district of the State. But if the facts of the case be clearly com prehended the difference between the two statements will cause no inconvenience. The question is merely one of names, and this can easily be made apparent, but it is needful to explain its nature as well as to show how much ground it covers, and which of the reports of progress of the Survey have the reading of their text affected by it. 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.