Excerpt from Summary of on-Line or Interactive Physico-Chemical Numerical Data Systems The development of multi-user computer hardware and operating systems and associated national and international communications networks has made it technically and economically possible to provide users with on-line access to a wide variety of data systems. Aside from bibliographic information, the data bases' that are now on stream practically around-the-clock include: marketing, economic, actuarial, financial, and regulatory data; demographic and other census statistics; and weather, ecological, geological, geographical, and other Earth data. Two of the leading us. Value-added networks - gte Telenet and Tymnet - offer more than 250 data bases. Nearly half of these are available on both networks. 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.