Excerpt from Use of Chart Readers for Analog to Digital Conversion of Hydrologic Data Both semiautomatic and automatic systems can be used to process data from every type of hydrologic chart so far encountered. Quite often, a few charts of one specific type can be more easily processed by hand than by machine. The usual test is quantity. The more charts to be processed, the more attractive becomes the chart reader. Decision between semiautomatic and automatic chart readers should be based on the constancy of the record trace, and whether there is more than one trace on a chart. In general, the more complex charts are best processed with the automatic system. 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.