Show tT T UNDERGROUND TELEPHONE How the Long System Dotween Now i York and New Haven Was Put In The longest undcground telephone line In tho world has recently been completed and extends from Now York t to Now Haven Conn n distance of over 70 miles If this system proves 4 mi ° tka ray v I IBTANDAHD MITUOD OF CROSSING I SHOUT niUDCSES to be a success Its extension to other cities may bo expected very soon The time may come when telephone poles in cities will be a curiosity al the advantages of underground wires i seem to more than compensate for the additional expense Thu objectionable appearance of a confused network ol f overhead wires ought to be sufficient f to condemn that system for cities and r tho liability to open circuits in case of high winds or accumulations of sleet on the wires makes It unreliable for all places Another objection 1q I tho danger occasioned when a telephone tele-phone wire becomes crossed with a highvoltage wIre This frequently occurs in thq overhead system but when tho two wires nro in separate t ducts n cross Is almost Impossible Tho underground line mentioned says Popular Mechanics has wires laId in ducts which are of sevoral dlf ferent types preference bnlng given to ono or the other according to the physical condition of tho country the 1 obstacles met with and the probability 1 oMuturo excavating or blasting In theM the-M locality Most of the coming work k was formed of vitrified tile sections but where heavy rock cuts wero encountered t countered creosoted wood ducts were used as these offer less possibility ol shattering whero future blasting I might cause trouble t Whero water was encountered tits wires were either run through subma iiI I = tt Lr we fjJ T IWrl THE BTRKUT CONDUITS rlne cables or laid In tile conduits encased en-cased in concrete Tho standard bridge croslng shown In Fig 1 was tho method employed for crossing al tho short bridges A number of three Inch pipes were covered with concrete and reenforced with steel rails at shown and tho wires wer then drawl through tho pipes The standar street construction Is shown in Fig 2 which Is a section through a manhole man-hole This shows the ideal location ol the underground service and was used in all tho city streets except whore obstacles ob-stacles which made this form of con atructlon impossible were encountered encoun-tered 1 |