. Bell telephone magazine . cted sta-tistics showing that with common bat-tery the instrument troubles were onlyone fourth as frequent as with themagneto system, and that, as a re-sult, subscriber stations would re-quire inspection only at infrequentintervals. The following year heestimated that with the common-battery system, the average speed ofoperation would be increased byforty percent, due to automatic sig-naling; and that the cost of battery maintenance would be reduced byseventy-five percent, clue to the cen-tralized battery. He also pointed outthe advantages the system offered forregi
. Bell telephone magazine . cted sta-tistics showing that with common bat-tery the instrument troubles were onlyone fourth as frequent as with themagneto system, and that, as a re-sult, subscriber stations would re-quire inspection only at infrequentintervals. The following year heestimated that with the common-battery system, the average speed ofoperation would be increased byforty percent, due to automatic sig-naling; and that the cost of battery maintenance would be reduced byseventy-five percent, clue to the cen-tralized battery. He also pointed outthe advantages the system offered forregistering calls by meter, for theapplication of coin-box service, andfor the extensive introduction of pri-vate branch exchanges. Open-wire Transposition Another development to whichMr. Hayess department made out-standing contributions was the de-sign of transposition systems foropen-wire lines. In 1886 the first line of the newlyformed long distance company wascompleted between New York andPhiladelphia. Originally it carried. A group of Mechanical Department engineers at 127 Purchase Street, Boston, in , W. L. Richards, H. D. Sears, Chauncey Smith, Jr., W. J. Hopkins; standing, E. H. Lyon, Anthony C. White l62 Bell Telephone Magazine AUTUMN twelve metallic circuits of hard-drawn copper wires—the first in-stance of a large number of metalliccircuits being carried on the samepole line. Tests soon showed thatthe crosstalk was as serious as it hadbeen with the grounded circuits pre-viously employed. This difficultywas overcome after months of hardwork by J. A. Barrett, consultingengineer employed by the long dis-tance company. Out of this work ofBarretts came the ABC system oftranspositions—the first to come in-to general use. Although employedfor many years, it was found to beinadequate as the business grew, andin 1898 was replaced by the so-calledStandard or four-arm system. Dur-ing 1904, an elaborate series ofmeasurements of direct capacitanceswas made by E. H. Col
Size: 1863px × 1341px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthoramerican, bookcentury1900, bookdecade1920, bookyear1922
