1882.] • on Electric Baihvays. 67 



adversaries saw the disadvantage of adding the weight of the loco- 

 iQotive to the weight of the train, whereas Stephenson was especially 

 struck with the enormous waste of power in the friction of ropes or 

 chains passing over pulleys. [Experiments were then shown proving, 

 first, that the mass of the locomotive necessitated the engine having a 

 greater horse-power to get up the sj)eed of the train quickly as well 

 as a greater horse-power to keep up the speed ; secondly, that the 

 friction and wear and tear of ropes, such as were employed on the 

 London and Blackwall Railway, would have been an insuperable 

 hindrance to the develojDment of railways.] From this was deduced 

 that, since in Stephenson's day the only feasible mode of communi- 

 cating the power of a stationary engine to a moving train was by 

 means of ropes, his decision to adopt the locomotive was perfectly 

 correct at the time it was made. 



Attempts have been made to propel trains by blowing them 

 through tubes, or by blowing a piston attached to the train through a 

 tube, but such attempts at jmeumatic railways have nearly all been 

 abandoned. The emjiloyment of air compressed into a receiver on the 

 train by fixed pumping engines stationed at various points along the 

 line, and employed to work comjjressed air engines on the carriages 

 has been effected with considerable success by Colonel Beaumont, 

 especially for tram-lines. The weight of the compressed air engine 

 is, however, still very considerable. Any system of pumj)ing water 

 through a pipe and employing the water to work a hydraulic engine 

 on the train is hardly worth considering, seeing that the mechanical 

 difficulties of keeping up a continuous connection between the moving 

 train and the main through which the water is j)umped seems in- 

 superable. Gas-engines worked with ordinary coal gas, stored perhaps 

 under pressure, might be employed on the moving train, but the 

 advantage arising from the absence of boiler and coal would be more 

 than compensated for by the fact, that the weight of a gas-engine per 

 horse-power developed is so much greater than that of a steam-engine. 

 None of these systems, then, of dispensing with a locomotive is by any 

 means perfect, and the success of the recent experiments on the 

 electric transmission of power has turned the attention of engineers 

 to the consideration, whether electricity could not successfully supplant 

 steam for the propulsion of trains and tram-cars ; whether it could 

 not, in fact, supply an efficient means of transmitting power, the 

 absence of which caused Stephenson to abandon ropes in favour of a 

 heavv locomotive engine. 



The whole question, like every similar one, is mainly a question of 

 expense ; and what we have to consider is, whether electric trans- 

 mission on the whole leads to greater economy than can possibly be 

 obtained by the employment of any kind of locomotive. The average 

 weight of a locomotive is about that of six carriages full of people ; 

 ten carriages compose an ordinary train, hence the presence of the 

 mass of the locomotive adds at least 50 per cent, to the horse-power 

 absolutely necessary to propel the carriages alone, and therefore at 



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