The practical telephone handbook and guide to the telephonic exchange (1906)
Poole, Joseph · New York, Macmillan Co. · leaf 165
ilarly at the other139 i4o PRACTICAL TELEPHONE HANDBOOK stations. The second line or earth terminal of each instrumentis connected to a special return wire, which, together withanother special wire, is run round with the others to a centralringing battery. Local batteries are provided for the… … jt-lSE
Telephone
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