540 PRACTICE OF AGRICULTURE. Part MI. 



given proofs, that it admits of being carried much beyond the limits of what -was for 

 niany years conceived to be possible, and to afford demonstrative evidence, that it may 

 be in future employed to a wider extent still, to which no limits can be at present assigned 

 or foreseen. 



3460. In countries the surfaces of which are rugged, or where it is difficult to obtain 

 water for lockage, where the weight of the articles of the produce is great in comparison 

 with their bulk, and where they are mostly to be conveyed from a higher to a lower 

 level ; in these cases, Telford observes, iron railways are in general preferable to canal 

 navigation. 



3461 . On a railway well constructed, and laid with a declivity of fifty-five feet in a mile, 

 it is supposed that one horse will readily take down waggons containing from twelve to 

 fifteen tons, and bring back the same waggons with four tons in them. This declivity, 

 therefore, suits well, when the imports are only one-fourth part of what is to be exported. 

 If the empty waggons only are to be brought back, the declivity may be made greater ; 

 or an additional horse applied on the returning journey will balance the increase of de- 

 clivity. If the length of the railway were to be considered, it may, it is supposed, with- 

 out much inconvenience, be varied from being level to a declivity of one inch in a yard, 

 and by dividing the whole distance into separate stages, and providing the number of 

 horses suitable for each portion of railway, according to the distance and degree of de- 

 clivity, the whole operation may be carried on with regularity and despatch. 



3462. Railways may be laid out so as to suit the surface of very irregular countries, at a 

 comparatively moderate expense. A railway may be constructed in a much more 

 expeditious manner than a navigable canal ; it may be introduced into many districts 

 where canals are wholly inapplicable ; and in case of any change in the working of mines, 

 pits, or manufactories, the rails may be taken up and laid down again in new situations, 

 at no very great expense or trouble. 



3463. The whole load to be drawn by one horse upon railways was at first put into one 

 waggon ; but now when the load is so much augmented, it has been found eligible to 

 divide it into many parts, so that no one waggon shall carry more than one or two tons ; 

 by this method the weight is so divided, that the pressure is never so great upon one 

 point as to be in danger of too much crushing the road j the carriages can be made much 

 more limber and light in all their parts {fig. 

 443.), and they are much more easily moved 

 and more manageable in all respects than 

 they otherwise would have been. And 

 another advantage of this arrangement, 

 which deserves to be particularly adverted 

 to, is, that it admits of shifting the carriages 



so as to leave a load, as it were, in parcels ^ lu^ i-U-^ li.^'^^H:'^ lu-^ 

 at different places where they may be required, without trouble or expense. This, when 

 it comes to be fully understood and carried into practice, will be a convenience of inesti- 

 mable value, a thing that has been always wanted, and never yet has been found, though it 

 has been diligently sought for. 



3464. Of the advantage of railways a striking proof is given by Anderson, [Recre- 

 ations, ^c.) It was formed by Wilkes near Loughborough. Its extent was about five 

 miles, and it led from a coal mine to a market. He found it so fully to answer his ex- 

 pectations after it was finished, that he communicated to the society of arts an account of 

 some trials he had made of it, requesting that such of the members of that respectable 

 institution as were desirous of information on that head, would do him the honor to wit- 

 ness some experiments that he wished to make upon it, for the information of the public. 

 A committee of the members was accordingly deputed for that purpose, and before them 

 he shewed that a moderate sized horse, of about twenty pounds value, could draw upon 

 it with ease down hill (the descent being one foot in a hundred) thirty-two tons, and 

 without much difficulty forty-three, and seven tons up hill, independent of the carriages. 

 The doctor concludes from these facts, that upon a perfect level a horse could draw with 

 ease from ten to twenty tons. It is observed, that Wilkes's railway, on which the 

 experiments were made, was, from local circumstances, laid upon wooden sleepers, and 

 is not so perfect as those done upon stone. But it is added, that twenty tons are the 

 load which such a horse could draw with ease, travelling at the usual waggon rate, in 

 boats upon a canal ; so that the number of horses required in this way will not be 

 much, if at all, greater than on a canal. Certain advantages attach to this mode of con- 

 veyance, which do not so well apply to a canal, and vice versa ; but it is not his intention 

 to draw a parallel between these two modes of conveyance. Nobody can entertain any 

 doubt, he thinks, about the utility of canals where they are easily practicable. He only 

 wishes to point out this as an eligible mode of conveyance where canals cannot be con- 

 veniently adopted. 



3465. Informing and constructing railways, the best line the country affords should 



