[35] 



U S. FISH COMMISSION STEAMER ALBATROSS. 



37 



The '^ life-time" of these lamps is warranted to be 600 burning hours, 

 and their cost is 85 cents apiece. 



SAFETY CATCHES. 



In event of a " short circuit" (an accidental con- 

 necting- of the -j- and — wires) by a good conductor 

 there would instantly- be generated sufficient heat 

 in the wires to melt them and to set lire to the ad- 

 jacent woodwork, and possiblj^ melt the armature also. 

 To prevent this, Mr. Edison has devised his cut-out 

 blocks and safety plugs shown in Figs. 13 and 14. 

 The wires of the circuit connect to the binding screws 

 in the blocks, while the plugs screw into the sockets 

 of the blocks when the circuit is completed through 

 the plugs, after the manner of the lamps; but the 

 wire which connects the two jioles of the plug is made 

 of a fusible alloy, which melts at about 400 degrees, 

 and the melting of this wire breaks the circuit. When 

 this happens all the lamps fed through that plug will 

 go out. These safety catches are placed on the main 



wires near the dynamo and on every branch circuit near the point 



where the mains are tai^i^ed. 



Fig. 12. 



Fig. 13. 

 ECONOMY OF THE SYSTEM. 



The writer indicated the engine with the current switched off; again 

 with forty-five, with fifty, and finally with seventy lamps (8 candle^ 



