Economic development of step-by-step auto-matic telephone equipment

G. K. Haspel (by letter): In general, only one connector group is required per 100 lines when these lines serve individual or P. B. X. subscribers, but for par-ty-line service it has been the practise to provide as many groups of connectors per 100 lines as there are parties on the party line, that is, for two-party service, tVO connector groups per 100 lines are required and for four-party service, four groups.