RAILWAYS. 



789 



nent railway, is a matter which can be decided only 

 l>y experience. Unless the railroad be supported 

 equally throughout its entire length, each rail must 

 be subject to some amount of deflection when great 

 weights are passing over it, and the extent of de- 

 flection is in some measure dependent also upon j 

 the speed, and in the opinion of Professor Barlow, 

 the additional resistance to the carriages, caused by 

 the deflection of the bar, will be equivalent to the 

 farriage being carried up a plane of half the whole 

 length, the other half being horizontal. The rails 

 first employed on the Liverpool and Manchester 

 railway weighed no more than 35 Ibs. per yard, but 

 were soon found to be inadequate to the purpose. 

 In the report of the directors of the Railway Com- 

 pany, made in January, 1834, they state, that " in 

 particular parts of the road, especially on the des- 

 cending lines of the inclined planes, the rails prove 

 too weak for the heavy engines, and the great speed 

 at which they are moved ; and from the breakages 

 which have taken place, the directors have thought 

 it expedient to order a supply of stronger and hea- 

 vier rails to be put down in those districts where 

 tlte present rails have been found insufficient." In 

 their report of July, 1835, they state that: "With 

 the plan recommended by the directors, at the last 

 half-yearly meeting, of relaying, from time to time, 

 certain portions of the road with heavier and stronger 

 rails, the directors have every reason to be satisfied. 

 A portion of the way has been recently laid with 

 parallel rails, 60 Ibs. to the yard ; and when, in 

 addition to the greater security afforded to the gene- 

 ral traffic by a firm and substantial rail, account is 

 taken of the diminished charge at which the road, 

 when so laid, will be kept in order, the directors 

 feel confident the proprietors will approve of their 

 persevering in the plan which they have thus com- 

 menced." In the report, 27th July, 1836, they re- 

 mark, " The proprietors are aware that portions of 

 the old and comparatively weak rails have been 

 gradually replaced with stronger bars. From the near 

 approach of the period when the Grand Junction 

 mid the North Union Railways may be expected to 

 bring additional traffic on the Liverpool and Man- 

 chester line, the directors have determined, with 

 the concurrence of the proprietors, to relay the 

 whole way more rapidly than they originally contem- 

 plated. In conformity with the contracts already 

 made, about one half the whole line will be laid with 

 new rails by the end of the present year. The great 

 advance in the price of iron will render the relaying 

 of the way a more costly work than was at first an- 

 ticipated ; but this is only one instance out of many 

 in which the Liverpool and Manchester company 

 have been constrained to purchase experience at a 

 very dear rate dear, at least if regarded in refer- 

 ence to their individual and pecuniary interests; 

 but cheap, if the proprietors, taking a more enlarg- 

 ed view of the great subject of railways, will 

 include in their consideration the beneficial results, 

 vast and undisputed, which will shortly be realised 

 by the country and the world." Mr Brunnell the 

 engineer of the Great Western Railway, has sug- 

 gested that a greater space should be allowed be- 

 tween the rails-tlian has been adopted on the Liver- 

 pool and Manchester, or London and Birmingham 

 railways, and the carriages being hung between 

 the wheels, the diameter of the wheels can be in- 

 creased, and with it the speed of travelling. 



Route. The first enquiry presenting itself in re- 

 spect to a railroad between two points, relates to 

 the choice of a route, where the nature of the terri- 

 tory permits of any such choice. In making this 

 election, the comparative distances, the amount of 



the character of the soil as to affording a good foun- 

 dation, the excavations and embankments necessary 

 to be made in order to bring the road within a cer 

 tain scale of inclination, and the difficulty or facility 

 of obtaining suitable materials for the construction 

 of the road, are all to be taken into consideration. 

 These investigations and comparisons cannot be too 

 rigidly and minutely made ; and it has been sug- 

 gested by experienced engineers, that in some of 

 the roads of this description constructed in the U. 

 States, great mistakes will be found to have been 

 made in this respect, in consequence of too great 

 precipitancy in fixing on a route. 



Gradients or Inclination. The scale of inclina- 

 tion to which the road is to be reduced, is necessarily 

 taken into consideration in fixing upon the general 

 route ; but still a choice often presents itself in parts 

 of such routes, between the expense of reducing 

 the rate of inclination, by excavations and embank- 

 ments, and the saving of expense by taking a more 

 circuitous route. Another question also presents 

 itself, namely, whether to reduce an acclivity, or 

 to surmount it ; and the manner of overcoming it is 

 a subject of inquiry at the same time ; for, the sur- 

 face of the ground having been examined and the 

 route determined, on a general scale of inclination, 

 within which the ordinary power used for transpor- 

 tation is to be applied, the whole line is either to be, 

 brought within this scale, or if an inclination ex- 

 ceeding it is admitted, it is to be overcome by the 

 use of an extra power. In such case, if the extraor- 

 dinary expense of reducing the inclination is not so 

 great that the interest upon this part of the original 

 outlay would exceed the additional expense of the 

 use of an extra power to overcome an inclined 

 plane, it will be a decisive reason in favour of re- 

 ducing the inclination. The amount of transporta- 

 tion to be accommodated will determine, in a great 

 degree, the expense of the extra power requisite to 

 overcome a given inclined plane. Another circum- 

 stance to be considered is, whether the extra power 

 to be used is that of horses, or steam, or water; for 

 the two former are comparatively more expensive 

 for a small than for a large amount of transporta- 

 tion, owing to the cost of maintaining them ; but 

 the difference is not so great where a water power 

 can be used. In some cases it may be better to 

 make deflections in the road, than to reduce inclina- 

 tions, or to use extra power. This will depend on 

 the kind of transportation and the importance of 

 celerity ; for if the object is mainly the transporta- 

 tion of increased weight by the same power, without 

 regard to the time, any deviation from a direct 

 course is less objectionable. But upon lines of pub- 

 lic travel, dispatch is of great importance. 



In the recently constructed railroads in Eng- 

 land, the iron rails are in general supported 

 by iron chairs or props, at a distance of about three 

 feet from each other. Lately the rails are made in 

 lengths of fifteen feet, so that two-thirds of the 

 sleepers or bearings are saved. Where the rails 

 rest on a line of wood, the track must be compara- 

 tively imperfect, since the wood will yield to the 

 weight of the load transported, and be slightly com- 

 pressed as the wheels pass, thus offering a continual 

 resistance. Where successive parts of the track are 

 formed by laying iron rails upon pine, oak, and 

 stone, the difference of power necessary to move the 

 same load on the different parts, will be evident in 

 the different degrees of exertion made by the horse, 

 where this power is used. Accordingly, if a soft 

 species of wood is used to support the iron rail, it 

 is of great advantage to interpose a line of oak or 

 other hard wood. A rail continuously supported 



intermediate transportation to be accommodated, by a line of stone will not yield to the weight of the 



