THE LOCOMOTIVE. 



24. When the magnitude of the capital invested in the locomo- 

 tive stock of a railway, jfhd the large proportion of the annual 

 revenue absorbed in maintaining it are considered, its economical 

 importance may be readily estimated. 



The locomotive stock may be primarily resolved into two classes 

 that which is employed in working the passenger traffic, and that 

 which is employed in drawing the goods trains. 



The passenger engines are so constructed as to draw light loads 

 at great speed, the goods engines heavy loads at a low speed. In 

 the one, the driving-wheels are large, so as to carry the train 

 forward through a great space by each stroke of the piston ; in the 

 other, they are of more limited magnitude, in order to give the 

 moving power a greater leverage upon the load. In the one, they 

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