On Railway Gradients. 117 



I need but refer to home authorities confirmatory of this 

 assertion, and point to what Engineers, formerly adopting the 

 " level theory," have in later years done. 



Mr. Brunei, in a report to the Great Western Directors, 

 dated December, 1838, strenuously advocates "the great 

 superiority of a line " approaching the level," and further states, 

 " On gradients of 16 feet per mile, the engine during half the 

 time is barely doing more than driving itself." In 1850, we 

 find him adopting gradients of eighty-jive and one hundred 

 feet per mile with entire success. 



Regarding the expense of working inclines, Mr. Vignoles, in 

 a paper read in 1840, before the members of the British 

 Association, states, " he had analysed railway expenses of 

 working, and reduced them to a mileage, &c, as deduced from 

 several years experience &c, under different circumstances, and 

 with greatly different gradients ;" and he adds, the result of 

 " this average seemed to hold good irrespective of gradients or 

 curves." 



Dr. Lardner gives an elaborate analysis of the working of 

 railway gradients : the result is so well known, I shall but allude 

 to it. He asserts that " a compensating effect is produced in 

 descending and ascending gradients, and that a variation of 

 speed in the train is the whole amount of inconvenience that 

 will ensue ; that the time of performing the journey will be 

 the same in both cases." I must, however, admit that the 

 gradients, to which the learned doctor alludes, are of the class 

 now known as "favourable," or flatter than 1 in 140 ; still, I 

 fearlessly assert, that even on ascending and descending planes, 

 where gradients of one hundred feet per mile are used, the 

 loss of time and speed will not amount to more than 30 per 

 cent., under disadvantageous circumstances, as contrasted with 

 a level hue. This result I obtain from the working of English 

 railways. 



In 1845, the Board of Trade report that " such gradients as 

 were before thought objectionable, are now adopted every day 

 as a matter of course ; and as the capabilities of the locomotive 

 have been enlarged, gradients of a class which woidd have been 

 a few years ago altogether impracticable, have come into general 

 use." 



Many statements have been hazarded relative to the increased 

 friction of descending planes on curves, contrasted with a direct 

 line. No practical result, however, of sufficient moment has 

 been elicited that will decide this question. 



From my own experience I am clearly of opinion, where the 



