The Birmingham age-herald., 1907-05-20

of miles operated by independent systems cannot be given, but as a recent careful estimate makes the number of independent telephone stations in the United States in the neighborhood of 2,000000, it is safe to estimate that in this country alone nearly if not quite 10, ,000,000 miles of tele- phone wire are Tn daily use. or enough to reach from the earth to the moon more than forty times. We think Of the sun as a luminary that is enormously dis tant from this planet Yet the telephone wire mileage of the United States would already cover about one-ninth of the dis tance and at the present rate of increase this copntry within few decades is ike ly to have wire enough, if such thing were possible, to loop complete tele- phonic circuit through the central energy plant of the solar system. An average of at least one telephone to nve persons
 is probable and our population continues to grow rapidly. That means very large wire mileage halI Q century hence.
 Much of this wire can be placed under ground. or the present wire mileage of the Bell system, 0 little more than half, or, to be exact, 3,241.4 All miles. has been drawn into conduits from the great reels covered with lead cable which are frequent sight ip our city streets. But it IS not pOSSlDle Ut pTtscHl lO put aii lSic- phone wire underground, and it may never be possible. Even for local systems the subterranean construction is expensive, so that only in larger cities and towns will the conditions of traffic permit it's introduction. Then as for the toll and long distance lines, which have enmeshed nearly the whole continent until practical ly every hamlet is telephonically connect cd with every other, underground con ctr of an q dar 1ooCth Ia practicable. because -burying the wires reduces their capacity for transmission of the minute currents which accomplish the marvel Of telephony, good overhead circuit of open wire enables the business man in New York to converse with the business man in Chicago or St. Louis al- most as readily as If he were in the next roon If the wires between Gotham and the Windy City were buried, even though the most improved form of conduit con- struction should be used. hardly nn 'n telligible sound could get through, for the current in cable circuit -uecays
 rapidly, In the more thlckly settled DOT tions of our country engineers are already declaring that the toll circuits must, so far as possible. be kept overhead and of open wire construction throughout their entire length for where one of>them is thrown into underground cable for few miles in the neshborhood of a city an appreciable effect on the long distance transmission is noted although In the urban system itself the service is abso- lutely satisfactory and even 'snappy," as the telephone men call it.
 The present extensive use of overhead cable involves a radical departure The telephone companies in the early days naturally followed the custom of the tele- graph companies in stringing single parts of wires on poles Whenever the business grew rapidly 1t became necessary to set very tall and heavy poles, often towering above the trees of the street or highway To these many crossarms were attached In order that the pole should accom- modate as many wires as possible. Even thus a pole would become overloaded. me exposure of so many wires offered a great chance for the collector of sleet in. the winter time and led now and then to one of those annoying breakdowns