Electric Lighting for Mines. 117 



wire. At suitable intervals iron boxes are provided, con- 

 taining a cut-out and coupling by which, the lamp can be 

 easily attached. 



Each lamp enclosed in an outer glass lantern with pro- 

 tecting wire guard has some 10 feet of flexible conducting 

 wire attached to it, provided with a coupling for attachment 

 to the junction-box. The lantern can then be suspended on 

 the iron tubing in any desired spot. The iron junction- 

 boxes are placed along the cross-cuts and levels at spots 

 selected, and are in excess of the number of lamps in use at 

 one time. It takes but a few seconds to change a lamp from 

 one spot to another ; and where required extra lengths of 

 flexible wires are provided, with couplings at each end, so as 

 to lead a lamp to a distant point. The lamps at the plats 

 are not joined to the branch leads, but direct and through 

 its own cut-out to the main wires. Thus any interference 

 owing to an accident or fault to any of the leads in the 

 levels will not affect the platlights, which are important ones 

 to keep constantly alight. 



By using leather washers for the covers of the junction- 

 boxes and lamps, it will be seen that the whole system is 

 waterproof, and that the lights will burn, even though the 

 mine should be flooded and the conductors and lamps be 

 under water. 



This is a matter of the utmost importance for alluvial 

 workings, where accidents from the inrush of water are by no 

 means unfrequent. In such cases the value of having a light 

 which cannot be extinguished should be highly estimated. 



Another important use for the electric light is at the 

 brace, where the light is exposed to the weather. In the 

 case of kerosene lamps, on a stormy night it is very 

 difficult to keep them alight, and then only at the expense 

 of several chimneys. 



The electric lamp at the brace is enclosed in a lantern, 

 having a reflector to throw the light on the ropes and skip 

 only, and controlled by a cut-out and switch fixed in a con- 

 venient part of the brace. Twelve months 5 experience with 

 the working of the light at one of the Sandhurst mines has 

 proved conclusively that with the precautions before men- 

 tioned no difficulty whatever can arise in any part of the 

 system, and that the incandescent lamp is more economical, 

 reliable, and affords a better illumination than any other 

 available method. 



