174 



ME. WILLIAM FAIRBAIRN ON THE 



whereas two engines of equal power raised the same weight, 

 or nearly so, at the rate of 16*85 miles per hour, which gives 

 an increase of speed of only l'S5, little more than 1| miles 

 an hour. These facts are confirmatory of the advantages 

 of working trains on steep gradients by the single engine, 

 whenever that can be accomplished, with light loads at a 

 moderate rate of speed. 



Having effected the arrangement and classification of the 

 experiments, it now becomes necessary to collect them in 

 such form as will enable us to arrive at correct results, and 

 to offer such remarks as may prove useful in determining in 

 what situations, and under what circumstances, the various 

 gradients on railways can be surmounted by the single en- 

 gine, and when the assistant engine can be applied with 

 advantage. To effect these objects the following summary 

 of results, first, of the goods, and then of the passenger 

 traffic, will be found sufficiently explicit to enable the en- 

 gineer to judge as to the amount of power required, and 

 whether or not the assistant engine would be conducive to 

 the interests of proprietors and the service of the public. 



SUMMARY OF RESULTS, 



As obtained from 270 Experimental Trips in the transit of Goods 



Trains on the Accrington Incline. 



In the above summary, it will be observed, that assum- 

 ing the area of the cylinders of the engines employed to be 



