150 MR. WILLIAM FAIRBAIKN ON THE 



afterwards it was deemed indispensable to lay out railways 

 as nearly as possible on a level, or with gradients not 

 exceeding 1 in 200 or 1 in 250, for which great sacrifices 

 were made, and large sums of money expended in cuttings, 

 tunnels, and embankments, in order to attain an easy 

 ascent, suitable to the engines then in use. 



The first locomotive engines were made respectively of 

 eight, nine, and ten-inch cylinders ; but finding them in- 

 effective and deficient in power, adhesion, &c, they were 

 progressively enlarged in all their parts, and the cylinders 

 increased firom 10 to 12 inches. Subsequently, the cylin- 

 ders were still further increased from 12 to 13 and 14 

 inches, and now they are constructed as high as 16 inches; 

 and in some cases engines of 18-inch cylinders are in use, 

 with all the parts in proportion, weighing from 25 to 30 

 tons. 



This great increase of power rendered the question df 

 gradients, in the construction of new lines of railway, of 

 less importance; and from the increased weight and in- 

 creased adhesion of the improved engines, gradients, which 

 on former occasions were considered impracticable, are now 

 surmounted without difficulty. 



On this point I may instance the Newcastle and Carlisle 

 Railway, where the gradients are about 1 in 106 ; on the 

 North Union they are 1 in 100 ; on the Birmingham and 

 Gloucester, 1 in 37 ; and more recently, in the Edinburgh 

 and Glasgow Tunnel, which is now worked by the loco- 

 motive engine, the incline is 1 in 42 ; and the Manchester 

 and Leeds (Hunt's Bank), from 1 in 46 to 1 in 60. Now, 

 all these gradients can be worked by the locomotive engine 

 as it now exists, with the exception, perhaps, of the 

 Lickey IncUne, on the Birmingham and Gloucester Line, 

 which requires two engines ; and I have no doubt, as fur^ 

 ther improvements are effected, and the powers of the 



