How Engineer Helps Railway 173 



One notices at once the absence of a 

 furnace door of the usual type, and it is 

 found that stoking is done through a chute 

 in the foot-plate, but there is a small door 

 in front which is found very handy for 

 lighting up and removing clinker. The valve 

 gear consists of one cam-shaft only and there 

 are no exhaust valves. The great feature of 

 the design is that the hot steam entering the 

 cylinders at each end flows in one direction 

 only, that is towards the exhaust ports. One 

 result of this arrangement is a uniformly 

 decreasing temperature from each end to 

 the middle of the cylinder barrel; it is this 

 peculiarity which may be said to account 

 to a very large extent for the high economy 

 of the engine. 



In the ordinary type of locomotive, 

 the ends of the cylinders are alternately 

 heated and cooled because the cold 

 exhaust has to be expelled from the same 

 end through which the hot steam was 

 admitted, the net result of such an arrange- 

 ment is that more coal is required, and if 

 it is not really needed, then it is certainly 



