148 THE POPULAR SCIENCE MONTHLY. 



not been obtained? There must be something wrong somewhere. As 

 Art emus Ward says, " Why is this thus, and what is the reason of 

 this thusness ? " 



Speed is the delinquent, and the cause of the loss of the great pri- 

 mary advantages : the vehicles on railways are propelled very fast ; 

 hence they involve great strength in their construction, and enormous 

 w T eight in proportion to the paying load carried. 



An old stage-coach, according to Nicholas Wood, weighed only 16 

 to 18 cwts., and would carry upward of 2 tons of paying passengers 

 with their luggage, or about T % of a hundred-weight of dead load to 

 every hundred-weight of paying load. Now, a third-class carriage 

 with four compartments would represent 2.8 cwts. of dead weight to 

 every 1 cwt. of paying load. Therefore, the stage-coach has the ad- 

 vantage over the third-class railway-carriage of 6^ to 1. 



It becomes impossible to institute any absolute comparison between 

 roads and railways at speeds above 10 miles an hour, because such 

 speeds are impossible on the former for any considerable distance. 

 Again, the question of a gradient has to be noticed, for in the preced- 

 ing remarks a level road and a level railway have only been con- 

 sidered. 



As has been explained, where steep gradients occur, the resistance 

 due to gravity so much outweighs that due to friction that rails afford 

 a comparatively insignificant advantage, and one which is entirely lost 

 if the stock has to be increased in weight 6^ times. 



It may easily be shown that, on a gradieut of 1 in 10, for instance, 

 taking the foregoing figures, the advantages of a steam-worked rail- 

 wav over a horse-worked road would be little more than one-fourth, 

 if the stock on the former be only 6^ times heavier in proportion than 

 the latter would require. Hence it follows that no railway having 

 gradients of 1 in 10 could be worth making (assuming such to be pos- 

 sible) unless the stock upon it were assimilated to that of the ordinary 

 omnibus or stage-coach type. 



In former times calculations were made by Nicholas Wood of the 

 comparative costs of conveyance on ordinary roads by horses; he 

 showed that on an average a stage-wagon could carry at the rate of 

 2 miles an hour profitably at 8c?. a ton per mile ; that a light van or 

 cart at 4 miles an hour could take for Is. a mile a ton of goods. Pas- 

 sengers in stage-coaches were charged 3c?. a mile each, or 3s. 6c?. a ton, 

 at 9 miles an hour. Now, let us consider what railways actually do. 

 At the present moment coals are conveyed at -fc?. per ton per mile, at 

 an average speed of 20 miles an hour; and this low rate actually 

 leaves a profit. Excursion-trains take passengers at less than \d. each 

 per mile, at twenty miles an hour, or at Id. a ton a mile. 



Now, bearing in mind the relative proportions of paying and non- 

 paying loads involved in carrying passengers and coals, a simple cal- 

 culation will show that a ton of passengers could be carried for 



