176 



FARMERS' REGISTER— UNDULATING RAILWAY. 



The problem is onCj the full illustration and de- 

 velopement of which would require the language 

 and symbols of mathematical physics ; some notion 

 of it may, however, be conveyed in such a manner 

 as to be intelligible to the general reader. We 

 shall first state what it is that the undulating rail- 

 way performs, in which the level railway fails ; 

 and we shall next explain the physical law on 

 which this depends. 



Hitherto, it has been received as a practical 

 axiom, that railways can only be advantageously 

 applied between points where a uniform dead level 

 can be obtained. Now the patentees of the undu- 

 lating raihvay maintain a proposition which is the 

 logical contradictory of this. They hold, that even 

 if the projected line be naturally a dead level, it 

 must be artificially cut into ujjs and downs, so as 

 to keep the load constantly ascending and descend- 

 ing until the journey is completed ; and in so do- 

 ing, they assert that tlie transport is produced in 

 a considerably less time with the same moving 

 power, or in the same time Avilh a much less ex- 

 penditure of the moving principle. Again, it has 

 been held as a practical axiom, that if on a rail- 

 way it becomes necessary to ascend from one level 

 to another, the ascent is most advantageously made 

 by a plane uniformly inclined from the lower to 

 the higher level. On the contrary, the patentees 

 of the undulating railway hold that the ascent is 

 effected with a lesser power, by dividing the in- 

 terval into ups and downs, so as to cause the car- 

 riage alternately (o descend and ascend until it ar- 

 rive at the upper level. Indeed, one of these pro- 

 positions ibllows from the other, for if a greater 

 momentum is generated in going from one point 

 to another of the same level, l>y undulation in the 

 railway, that excess of momentum will carry the 

 load to a greater height than the momentum which 

 the same power would geneiate on a level railway. 



These facts have been illustrated by a small 

 model on a wooden railway in the Adelaide street 

 exhibition -room. We have ourselves at that place 

 instituted the following experiments, with the re- 

 sults here detailed. Tlie moving poAver was a spi- 

 ral main spring regulated by a fusee : a load was 

 placed on a level railway of such an amount that 

 the moving power was barely able to overcome the 

 friction, but incapable of moving the load. In this 

 state the carriage and load were transfeircd to the 

 undulating railway, and the same moving power 

 impelled tlae load with ease and with considerable 

 velocity from one end to the other ; and lest any 

 difference of level should exist between the extre- 

 mities, we caused the same experiment fo be made 

 in the contrary direction, which was attended with 

 precisely the same result. Hence, it was evident 

 that, at least with the model, a power incapable of 

 transferring the load between two points at a given 

 distance on a level railway, transferred the same 

 load with facility and despatch through the same 

 distance on the undulating railway. 



Our second experiment was as follows: — We 

 loaded the carriage in the same manner on the le- 

 vel railway, so that the power was barely equal to 

 the friction, but incapable of moving the load. 

 We then transferred the power and load to a rail- 

 way, the remote extremity of which rose above 

 the nearer extremity at tJie rate of one inch in 

 eight feet. The power which was thus utterly in- 

 capable of moving the load on the level, easily 

 transferred the same load fi-om end to end of the 



undulating railway, and at the same time actually 

 raised it through one perpendicular inch for every 

 ninety-six inches of its progress along the horizon- 

 tal line. 



Among the scientific men Avho have witnessed 

 this exhibition, many, it is said, have declared, 

 what indeed appears at first to be the case, that the 

 result is contrary to the established principles of 

 meclianics. We do not perceive, however, any 

 difficulty in th.e phenomenon. 



The effective impelling power when a load is 

 tracked u[)on a railway, must be estimated by the 

 excess of the actual impelling power above the 

 friction. Now, it is well knoAvn that the friction, 

 being proportional to the pressure, is less on an in- 

 clined than on an horizontal railway. The same 

 impelling power which on the level raihvay is on- 

 ly equal to the friction, and therefore incapable of 

 accelerating the load, becomes effective on the in- 

 clined railway, where it is greater than the fric- 

 tion. The excess therefore becomes a means of 

 generating velocity, so that when the load arrives 

 at the extremity of the undulating line, a quantity 

 of velocity has been communicated to it, which is 

 proportional to the excess of the friction on the un- 

 dulating above the friction on the level line. This 

 is, theoretically speaking, a decided and undenia- 

 ble advantage which the inclined railway posses- 

 ses over the level. We could make this point still 

 more clear, if we were addressing mathematical 

 readers. 



Now, if it be admitted that at the extremity of 

 the undulating line, a velocity is generated in 

 the moving body much greater than any which 

 could be produced by the same power acting on 

 the level line, it will follow demonstratively that 

 this velocity Avill be sufficient to carry the load up 

 a certain height, bearing a fixed proportion to the 

 velocity itself; and hence it will be perceived that 

 a moving power, which is incapable of moving the 

 load on a dead level, will be capable not only of 

 moving it between the extremities of an undula- 

 ting line when at the same level, but even of rais- 

 ing it to a higher level. 



Bwt the practical application of this principle 

 seems to promise still greater advantages. In the 

 above reasoning, we have assumed that the impel- 

 ling power acts with a uniform energy in accele- 

 rating the motion of the load. This, however, is 

 not the case when steam power is applied : the 

 load soon attains a maximum velocity, and the en- 

 gine becomes incapable of supplying steam fast 

 enough to produce effective pressure on the piston. 

 The cylinder, in this case, receives steam from 

 the boiler only at the same rate as it is discharged 

 by the motion of the piston, and scarcely any di- 

 rect effect is produced by its pressure on the pis- 

 ton. In the undulating railway, the working of the 

 engine will be suspended during each descent, and 

 a part of the succeeding ascent. In this interval 

 the steam will be nursed and accumulated so as to 

 be applied with its utmost possible energy the mo- 

 ment the velocity on the brow of the hill begins 

 fo decline. W hen the load surmounts the sum- 

 mit, and begins to descend the next hill, the ope- 

 ration of the engine will be again suspended, and 

 its powers reserved, and accumulated for the next 

 ascent. The duty of the engine will thus be, not 

 to produce steam constantly at a great rate, but to 

 produce steam of excessive energy for short and 

 distant periods. Every one who knows the prac- 



