[Electric engineering.] . f couplingboxes or junction boxes. Sometimes, however, joints mustbe made without the use of these boxes, in which casesthe job must be very carefully done. First, the soldered end of the cable is cut off and thecable carefully examined for moisture. If a little moisturebe present and there is still more than enough room for thejoint, it is allowable to cut off another short length. Ifindications of moisture are still present, heat should beapplied to the lead covering, starting from a distance and /. III.—9 22 ELECTRIC TRANSMISSION. 15 proceeding along the cable to t
[Electric engineering.] . f couplingboxes or junction boxes. Sometimes, however, joints mustbe made without the use of these boxes, in which casesthe job must be very carefully done. First, the soldered end of the cable is cut off and thecable carefully examined for moisture. If a little moisturebe present and there is still more than enough room for thejoint, it is allowable to cut off another short length. Ifindications of moisture are still present, heat should beapplied to the lead covering, starting from a distance and /. III.—9 22 ELECTRIC TRANSMISSION. 15 proceeding along the cable to the end. Thus the moistureis driven out at the cut. When the use of torches is notallowed on account of gas in the manholes, hot insulatingcompound, such as boiling paraffin, may be poured over thecable. This process is known as boiling out. To ascertainwhether moisture is present, the piece last cut off is strippedof its lead covering and plunged into hot insulating com-pound. If bubbles rise, moisture is still fig. 26. When all trace of moisture has disappeared, the lead cov-ering is removed for a convenient length from each of theends to be joined and the insulation is cut away for ashorter distance from the end, leaving a certain lengthbeyond the lead. A lead tube of sufficient diameter to fitover the cable sheath and of a length great enough tocover the joint to be made is slipped over one end of thecable and back out of the way. Now, if the conductor be § 15 ELECTRIC TRANSMISSION. 23 small enough, the regulation telegraph joint is made andsoldered. But if the conductor be stranded or of largecross-section, the ends are cut square, butted together, andsoldered, and made much more secure by a copper sleeve,which is soldered over all. This sleeve is open at oneside, so that solder may be run in until the strands arethoroughly saturated. The joint is now covered withinsulating tape to the height of the lead covering. A layer of paraffined paper may be wrapped on o
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