LOCOMOTIVE ENGINE AND RAILWAY GRADIENTS. 



175 



the measure of the force exerted at a given velocity, and 

 supposing the power of the single engine to be represented 

 by 427*2, we thus have a load of 57 "1 tons carried up the 

 different gradients of the incline at the rate of 5*73 miles 

 per hour. This duty, when compared with the double 

 engine, whose representative of force is 818'8, is rather more 

 than twice that of the single engine, a load of 117*2 

 tons being transmitted over the same gradients at the rate 

 of 5*49 miles an hour. From these results we must infer, 

 that in the transit of heavy trains at a low rate of speed, the 

 advantages are not much in favour of the single engine; yet 

 in cases of light trains, at a higher rate of speed, the benefits 

 arising from the use of the single engine are sufficiently 

 evident to secure it the preference, in every instance where 

 the load is duly and properly regulated to the power of the 

 engine. These facts are, however, more clearly developed 

 in the experiments with the passenger trains, as follows : — 



SUMMARY OF RESULTS, 



As obtained from 123 Experimental Trips in the transit of Passenger 

 Trains on the Accrington Incline. 



