TELEPHONE SYSTEM OF THE UNITED STATES 



59 





Fig. 47 — Telephone repeater building at Princeton, New Jersey on New York- 

 Philadelphia cable route. Building now houses 1 100 repeaters. Ultimate capacity 

 2200 repeaters. 



Fig. 48 — Earth boring machine and derrick. Will bore 60 centimeter hole 2 

 meters deep in loam or clay soil in about one minute and in stone or frozen soil in 5 

 or 10 minutes. Derrick operated by power driven winch for setting poles. Truck 

 provided with four wheel drive. 



