LOCOMCrtrVE ENGINE ANt) RAILWAY GEADIENTS. 173 



In the above experiments we have a still further exem- 

 plification of the inefficacy of the assisting engine, as the 

 ratio of the load carried to the speed attained is remarkably 

 consistent whenever the assistant engine is employed ; and 

 this is the more strikingly apparent as the greatest load, 

 40 tons, raised in February 25th, is only equal to that drawn 

 by the single engine recorded in the preceding Tables, the 

 speed being reduced to its equivalent of the load. 



TABLE XIIL 



PASSENGEil TEAINS. 



Dates. 

 1850, 



Mar. 2 



» 

 4 



i> 

 5 



15 



Mean. 



Feb.2u 

 27 

 Mar. 6 



Mean . 



Gro«»wt 

 of Train, 

 exclusive 

 ofEo^ne 

 and Ten- 

 der, in tons 



20 

 25 

 20 

 40 

 30 

 45 

 25 

 30 



29-4 



20 

 30 

 25 

 35 

 35 



29-0 



Time o 

 copied 

 travelling 



from ttie 

 l»ottoni to 

 tlie tup of 



incline. 



6 

 6 

 6 

 9 

 7 

 H 



712 



6 



9 



11 



8-0 



Average duty performed = X9-4, at 

 I6'86 miles an hoar. €h«ate*t load,' 

 iS> tons, at 109 miles per hour. 



Average duty peribrmed = 29 tons, at 

 1&- miles an honr. Greatest load, 

 35 tons, at 13'33 miles per hour. 



The mean duty performed by the double engines in the 

 first experiments, is similar to that attained by the leading 

 and assistant engines in the conveyance of the trains at 

 different periods of time. They are all of them in their 

 united capacity defective ; and again, computing the work 

 done with the power employed in the above experiments, 

 it is evidently in favour of the single engine. Twenty-nine 

 tons, it wuU be observed, were conveyed to the top of the 

 incline at the rate of 1 5 miles an hour by the single engine ; 



