Excerpt from The Bell System Technical Journal, 1938, Vol. 17: A Journal Devoted to the Scientific and Engineering Aspects of Electrical Communication During the last few years new methods and apparatus have been developed and radical changes made that greatly improve the situa tion both from an economic and operating standpoint. The new measuring instruments are much less costly than the types heretofore available and are as stable in operation and as simple to use as am meters and voltmeters. In the local plant the decrease in cost and complexity and improvement in operating methods has justified per manent installations in many of the larger offices while the newer forms of portable apparatus are being much more extensively distributed than earlier types. For the toll plant the improvement consists in doing away largely with the centralized transmission testing point. The regular test board force now can make transmission measure ments at their test boards and the r'epeater attendants can measure the performance of the repeaters while working on them. The work is so simple and the maintenance forces are so well trained that a special transmission testing force is not required. 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.