Some telephone switching problems

The paper attempts to analyse and explain in an elementary manner the problems involved in inter-connecting the various subscribers in a single telephone area, both manually and automatically. Technical terms are defined, the apparatus used in both cases is briefly described, and the inherent advantages of the automatic system are illustrated by analysis and comparison of the operations and signals involved in an isolated exchange. Automatic operation of larger and of multi-exchange areas is explained by a similar process of comparison, and the automatic devices used are then described in more detail, the essential desiderata being discussed.