3$6 RAILWAY CONSTRUCTION, 



than the ordinary locomotive. Until there is very clear evidence 

 that electricity is cheaper, there will not be any great induce- 

 ment for its general use as a motive-power on ordinary railways. 



Experiments have been made on some existing railways to 

 ascertain how far this new motive-power can be made service- 

 able under special circumstances. In one case, a powerful 

 electric motor-car has been introduced for working frequent and 

 heavy trains through a long tunnel, where the atmosphere with 

 ordinary steam locomotives became foul almost to suffocation, 

 and the result has shown that the traffic can be hauled efficiently 

 by electricity, and the air in the tunnel maintained pure and 

 clear. In this instance, the question of cost was of secondary 

 importance, the primary object being to avoid the asphyxiating 

 gases emitted from the ordinary locomotives. 



In other cases, specially designed electric motor-cars have 

 been constructed with a view to obtain a higher speed for pas- 

 senger trains than is at present attained with the locomotives, 

 and the trials made have proved that these cars could reach a 

 high speed, but so far only with limited loads. Experiments are 

 still going on with larger and improved machines, from which it 

 is expected to obtain both high speed and much increased haul- 

 ing power. 



It is more than probable that amongst the earliest practical 

 applications of electric motive-power on existing railways will 

 be its introduction as an auxiliary on the steep gradients of some 

 of the mountain railways abroad. In many of these regions 

 there are millions of gallons of water running to waste down 

 the ravines, a portion of which could be utilized in working 

 powerful generating plant, to drive strong electric motor-cars for 

 assisting the ordinary locomotives up the steep inclines. In 

 such localities, with free water-power, the cost of the electricity 

 would be at a minimum, while the cost of the ordinary locomo- 

 tive would be at a maximum. 



In whatever form the electric motor-car may be designed, we 

 are brought face to face with the old axiom, that there must be 

 a certain amount of weight to obtain a certain amount of 

 adhesion ; but there will be one important point in favour of the 

 motor-car, that whereas in the ordinary locomotive the weight 

 for traction can only be distributed over a few working wheels, 

 the electric arrangement may distribute it over a much greater 

 number, and so diminish the insistent weight of each wheel upon 



