Popular science monthly . is used in fieldwork for tapping telephone wireswhere it is necessary to make a call onthe line at any point. It is made fromthe body of the arms that form theordinary machinists divider. The sharp,tapering points are cut from a 9-in. tool,leaving square stubs 5 in. long. In theordinary divider the arms are set apartto allow space for the spring. Thearms must be bent to take up the spaceso that their inner surfaces come closetogether, then holes are drilled withtheir centers on the parting surfaces sothat one-half the hole is in each of those holes are show
Popular science monthly . is used in fieldwork for tapping telephone wireswhere it is necessary to make a call onthe line at any point. It is made fromthe body of the arms that form theordinary machinists divider. The sharp,tapering points are cut from a 9-in. tool,leaving square stubs 5 in. long. In theordinary divider the arms are set apartto allow space for the spring. Thearms must be bent to take up the spaceso that their inner surfaces come closetogether, then holes are drilled withtheir centers on the parting surfaces sothat one-half the hole is in each of those holes are shown havingdifferent sizes to admit wires of differentdiameters. Small holes are drilled at rightangles to these holes to intersect the half-hole in one arm andsteel phonograjjhneedles are insertedin them. Another small holeis drilled through onearm anil intersectedat right angles withanother, which istapped to receive aknurled head machinescrew. This is usedfor attaching a con-necting wire to thereceiver of the In ordinary use the connector is heldon the wire by hand, but if connectionsare wanted for any length of time it isbest to retain the wing with its nut andscrew. In this case the wing should becut off, allowing only a ^^-in. stub toproject. The device is opened wideenough to clear the stub of the wing toadmit the wire, then it is closed and thewing-nut set. The needles should notproject too far or they will se\er the wire.
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectscience, bookyear1872
