LOCOMOTIVE STOCK. 



mile. To such a statement there can be no objection, provided 

 it be made with the understanding that it applies to railways- 

 only which have a certain understood amount of average traffic. 



But it is clear that, with every variation of the traffic upon the 

 proposed railway, there must be a corresponding and proportional 

 variation in the necessary amount of locomotive stock. 



40. A legitimate mode of comparing the merits of the manage- 

 ment of the locomotive department will be found in the estimate 

 of the average daily mileage of the engines. 



It is evident, that if we find on one railway for example, the 

 North-Western, the engines performing a daily mileage of 45 

 miles, while on another the North of France, we find them per- 

 forming a daily service under 30 miles, that the locomotive stock 

 in the one case was more profitably managed than the other in 

 the ratio of 2 to 3, it being understood that other things are similar. 

 But even in this comparison it would be necessary that the length 

 and weight of the trains should be taken into account ; for if it 

 prove that the weight of the train drawn 30 miles is greater than 

 the weight of the train drawn 45 miles in the proportion of 3 to 

 2, then the useful labour of the engines will, after all, be the 

 same. In short, the test, and the only test, of the useful effect of 

 the locomotive power is the actual mileage (including in that term 

 the quantity) of the traffic which it executes in a given time. 



41. The conditions which determine the amount of the loco- 

 motive stock necessary to work any given railway form a very 

 important subject of inquiry in railway economy; but it is a subject 

 upon which we as yet possess but scanty and unsatisfactory data. 

 As has been already stated, railway authorities have, with more 

 rashness than skill, given a sort of rough estimate of it at so much 

 per mile. This must, however, be regarded as utterly unworthy 

 of attention, for the very intelligible reasons already explained. 



The amount of locomotive stock depends exclusively on the 

 mileage of the traffic. The question is thus reduced to the determi- 

 nation of the number of engines necessary to work a given mileage. 



If we assume the results of the working of the North-Western 

 lines as a general modulus, it would follow, that to find the 

 quantity of stock necessary for working a given daily mileage, 

 it will be sufficient to divide this mileage by 45 ; the quotient 

 will express the requisite number of locomotive engines. 



42. From calculations based upon authentic statistical returns 

 which were published in a series of articles, written by me for the 

 "Times," in 1851, it appeared, that in the year 1850, the gross 

 receipts of all the European railways then in operation, amounted 

 to 23,309000/., of which 12,755000^., or about the half, was 

 collected on the railways of the United Kingdom. 



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