TKANS ACTIONS OF SECTION J. 497 



vation. On the other hand, an increase of gauge will require 

 a corresponding increase in the contents of the cuttings. 



The width of cuttings protected by retaining-walls, the 

 breadth of tunnels, and the clearance required at bridges, all 

 depend on the width and construction of the rolling-stock, not 

 on the gauge. 



Carriages with side-doors require greater clearance than 

 those opening only at the ends. 



Purchase of Land. 



Taking into consideration the many advantages arising from 

 reserving a wide strip of ground on each side of the actual 

 track, and the difficulty of obtaining any such additional width 

 after the line has become hemmed in by the progress of 

 settlement, it seems hardly worth while to discuss the saving 

 which might be effected in the cost of land for the construction 

 of a railway in a new country by the reduction of a foot or two 

 in the gauge, although in taking a line through the heart of 

 either London or Paris such a consideration might have some 

 weight. 



Permanent- WAY . 



The length of sleeper and width of ballast will be reduced 

 with the gauge, but with a given weight of engine this must 

 be made up for by an increase in the number of sleepers and 

 depth of ballast, to give equal support on the 3ft. Gin. and on 

 the standard gauges. 



With the reduction of the gauge, the greater the injury 

 to the rail from the beat of the engine, the speed remaining the 

 same. Hence, to produce equal results with the 3ft. Gin. and 

 the standard gauge, a stronger rail must be used on the narrow 

 gauge. 



The conclusion to be drawn from these premisses is as 

 follows : that nothing is to be gained in constructive cost by 

 the reduction of the gauge except in the earthwork of the cut- 

 tings, whilst on the other hand the cost of the earthworks 

 may be greatly increased by the limitation to engine-power 

 caused by this reduction, and the necessity of obtaining 

 flatter grades than would be required with more powerful 

 engines. 



Maintenance. 



We next come to the cost of maintenance. Here at once 

 the voice of experience speaks with no uncertain sound. The 

 cost of maintaining the road in order rises rapidly with the re- 

 duction of the gauge ; and this is easily understood. Not only 

 does the decrease in stability render it more necessary to keep 

 the levels of the rails in perfect adjustment, but the greater 

 overhang of the rolling-stock exerts a pounding action upon 

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