The general principles of estimating telephone traffic between districts in an urban network were also outlined; although the variables are numerous it was possible to achieve fair' accuracy in forecasting the Welephone community of interest" between districts, Automatic methods were being widely applied in telephone communities and in this, and in metropolitan networks, calls were not necessarily routed direct in all cases, but might be connected via alternative or tandem routes often shared by calls from other communities, in Order to gain most economic use of expensive, relatively long and possibly technically complex inter-office trunks through the gain in call carrying capacity with larger trunk groups.
Text read from the printed page and cleaned; old type leaves the occasional error.