306 



RAILWAY. 



Railway, system are everyday more apparent. A public rail- name, at his iron works of Butterly, near Derby. Railway. 

 way is indeed now executing, under the direction of That gentleman, whose science and experience give Vvy^ 

 Mr" Granger, between the Forth and Clyde canal, and great weight to his opinion, had, upon one occasion, a 

 the extensive coal field in the vicinity of the Monk- horse weighing about 10 cwt. yoked to 4^ cwt., or 



504 lb., suspended over a pulley in a pit, which the 



Construc- 

 tion of rail 



ways. 



Effective 

 power of 

 the horse. 



land canal, near Airdrie. 



In noticing the construction of railways in this place, 

 ' we conceive it only to be necessary to describe what 

 may be considered the chief points of the system, leav- 

 ing minor details, which may now be examined in al- 

 most every district of the country, by those who are 

 professional or curious. In pursuance of this view we 

 observe, that every practicable effort should be made, 

 to form the line of draught upon one level, or upon a 

 succession of level reaches, connected either by inclined 

 planes or perpendicular lifts, according to the circum- 

 stances of the ground. The line of direction of a rail- 

 way is another feature of this measure, which in many 

 instances is too apt to be overlooked. It has been ob- 

 jected to a canal with long reaches in direct lines, that 

 the water is apt to be collected at the further end 

 during high winds, so as to overflow its banks ; but as 

 this does not apply to a railway, it ought to be carried 

 as directly as the situation of the country will admit ; 

 and wherever a turn becomes unavoidably necessary, it 

 should be formed upon a curve of as large a radius as 

 can be conveniently procured, attention being at the 

 same time paid to lay the inner rail somewhat lower 

 than the outer one, by which part of the friction in 

 bringing round the waggons will be avoided. To 

 show the advantage of the direct line more fully, we 

 observe, that in an up-hill draught, a carriage may be 

 conceived as in the state of being continually lifted by 

 increments proportional to its rise and progress upon 

 the road. In winding about, a similar effect is also 

 produced, as the carriage may be said to be continually 

 brought from a state of rest to that of motion, in a man- 

 ner perhaps not less detrimental to the effective power 

 of the horse, than the up-hill draught. Though the 

 horizontal or level line is the most desirable, where the 

 traffic is reciprocally carried both ways, yet where the 

 load is all in one direction, a declination towards the 

 point of discharge will naturally be given at such a 

 rate as the situation of the ground will afford, the 

 downward draught being always regulated according 

 to the number and weight of the empty or return-wag- 

 gons which the horse can draw. Perhaps this will be 

 best accomplished by a fall of four inches to the chain of 

 22 yards, being at the rate of one perpendicular to 198 

 horizontal. 



To ascertain the effective power of an active horse, 

 the proper criterion seems to be that of his weight. In 

 the year 1817, the writer of this article made some ex- 

 periments upon this subject, which he verified by the 

 French instrument called the dynamometer,* applied 



horse drew up with extreme labour, the same weight 

 requiring the united exertion of eleven men. Mr. Jea- 

 sop is led from observation, to estimate the friction of 

 a well-laid edge railway, to be equal to a rise in th 

 road of about four inches in a chain. He further finds, 

 that upon one of his edge railways, with a rise of 44 

 inches to the chain, a horse takes eight tons up-hill, and 

 is never allowed to work with less than six tons : from 

 all which we conclude, that a horse such as we have al- 

 luded to,' will track 10 tons of goods upon a level rail- 

 way, exclusively of the weight of the waggons, as dai- 

 ly exemplified in the work done upon the railways at 

 the collieries of the Earl of Elgin, and Sir John Hope 

 of Pinkie. Since, therefore, so much more can be done 

 upon a level than upon an inclined road, it is to be re- 

 gretted that so little attention is paid to the formation 

 of the former, which gives so decided an advantage, 

 especially to the railway system. It is even not un- 

 common to hear of a preference being given to an un- 

 dulating line of road, on the supposition that the horse 

 is more fatigued by a constant draught upon a level 

 road, than by the irregular exertions of an up and down 

 hill journey. This opinion is attempted to be support- 

 ed by such statements, as that the horse's chest is there- 

 by enlarged, and his wind improved, and that different 

 muscles are brought into action on every change of po- 

 sition. It never seems to be taken into account, that 

 relief is occasionally given by the slow motion up hill, 

 which after nil, is not half so beneficial for the animal, 

 as the same slow pace would be upon a level road. Here 

 the postboy generally performs his stage of 12 miles at 

 least half an hour sooner than he would travel the same 

 distance upon a hilly road. Under the article ROADS 

 and Highways, we shall show the fallacy of the doc- 

 trine above alluded to, by quoting Dr. Barclay, so emi- 

 nent in comparative anatomy, and for his scientific 

 knowledge in all that regards muscular motion. These 

 arguments about hilly roads can hardly, however, be 

 said to apply to the railway system, where the power 

 of the horse is understood to be adapted to a uniform 

 strain ; and it is upon this principle that we perceive 

 more fully the advantages of a level line of road. 



In some situations, the level line of trackage is pre- Methods 

 served by the occasional introduction of inclined planes, fbrpreserv- 

 on which the waggons are transported by machinery '."& a lerel 

 from one level to another, impelled generally by steam, Iineofroa( '- 

 water, or animal force. Where the load is all in one 

 direction, as at the collieries of Newcastle, the slate- 

 quarries of Penrhyn, and in many other places, the 



to trackage upon the Forth and Clyde canal, and also empty waggons are drawn up inclined planes by the 



on the Carron Company's railways, when it appeared, descent of the full ones. This improvement is said 



that a horse weighing about 10 cwt., in his ordinary to have been first introduced at the Tyrone collieries 



working state, exerted a force equal to 160 lb. ; and in Ireland, by Mr. Davis Duckhart, an engineer of 



that a force of about 12 lb. was sufficient for the track- the Sardinian service. Notwithstanding the extensive 



age of one ton upon a well-laid level railway. This application of the inclined plane to railways, both 



by calculation, gives 13 tons and 7 cwt. as the work of with and without the use of the steam engine, it still 



a horse, which in practice is equal to about 10 tons of remains a desideratum to obtain some effective mode 



goods, exclusive of the waggons. We are, however, of lockage or perpendicular lift, which shall be more 



aware that 8 or 9 tons in many cases proves full work, commodious to the circumstances of an undulating 



when the rails are not laid upon proper principles, or tract. of country. Surely, in the present advanced 



not kept in good order. state of things, it cannot prove any serious obstacle 



Some interesting experiments on this subject have to the efforts of professional men, to provide a 



been made, and obligingly communicated to us by Mr. convenient apparatus, capable of lifting a train of 



Josias Jessop, son of the late eminent engineer of that railway waggons seriatim on the principle of canal- 



* See the article DYNAMOJIETEJI in this work, voL VIII. p. 298. 



