Wilrtemberg 



433 



at Stuttgart is very well done, and reflects great credit on its de- 

 signers and constructors. The cables laid in these conduits are 

 some of twenty- five, others of twenty-eight pairs. Each trough can 

 contain therefore 28 x 5 = 140 pairs, and a six-trough conduit 840 

 pairs. The cables themselves are of various types. 



Lightning-guards, contained in weather-tight iron boxes and 

 provided both with fine fusible wires and toothed dischargers, are 

 always placed at the junction of overhead with cable lines. Fig. 1 56 

 is a cross- section of such a box, showing the connections of one 





MAN -HOLE 



DRAW-BOX 



FIG. 155 



wire. The cable end is sealed with insulating material, the wires 

 spreading out, each to its lightning-guard, the other side of which 

 (the box being fixed to the standard) is joined by a rubber- 

 covered wire to the open wire beyond the insulator. All joints are 

 soldered. Instead of making the junction between the copper 

 and steel in the running wire as shown, where voltaic action to 

 the detriment of the galvanised steel is bound to take place, it 

 would be better to leave a long tag of steel wire after making 

 off the turn round the insulator, thread it through a vulcanised 



F F 



