XOCOMOTIVE ENGINE AND EAILWAY GRADIENTS. 159 



with heavy trains, at velocities varying in the ratio of the 

 powers of the engines and the loads respectively. A slight 

 drizzling rain was prevalent during the last two experi- 

 ments, which kept the rails wet, and consequently proved 

 unfavourable for the experiment. The engine, however, 

 retained its full power from the commencement to the top 

 of the incline, without slipping. 



The next experiment was on the Halifax incline, which 

 contains three distinct gradients, varying, in a distance of 

 nearly two miles, according to the following longitudinal 

 section. 



Experiment 5. 



K SSOYARDS ^ lOlO YARDS ^-—880 YAH DS -» 



I CRADIBNT I IM 44^ ; CRABICNT I IN £3^ | CRADIEMT I IN 73 L \ LIVKU 



-•J370 YAftDS. 



With the same engine (the Scheldt) the ascent was ac- 

 complished, with a load of 11 tons 1 cwt, exclusive of the 

 engine and tender, in 4 minutes, being at the rate of 

 upwards of 28 miles an hour. 



The performance of the Scheldt engine obviously shows 

 that a considerable saving may be effected in the original 

 outlay of great numbers of railways, by the introduction of 

 a class of engines calculated to work the different gradients 

 at a rate of speed corresponding with the nature of the 

 traffic ; and, notwithstanding the sacrifice of time, and the 

 increased expenditure of fuel that would have to be made 

 in making the ascent of the gradients, that loss and expen- 

 diture would, nevertheless, be compensated, to a consider- 

 able extent, by the increased velocity, and consequent 

 saving of coke in the descent. 



But in fact, the extra locomotive power which under 



