CHAPTER XVII. NARROW-GAUGE RAILWAYS. The art of mining may be said to have given birth to the railway system. Not only was the steam engine primarily employed in mining, and developed in obedience to the necessities of that industry, but long before the use of steam as a motor the idea of traction upon tramways was originated, so far as we can now discover, in mines. It dates back, according to some authorities, to the Egyptians, who made use of this auxiliary in their quarries. But mining has scarcely reaped the full benefit of the combination of steam-power and rails, which has been utilized to so astonishing an extent in commerce and travel. Mines are generally located in more or less mountainous districts, presenting to the railway engineer unusual difficulties of grade and curve, and thus enhancing the cost of construction, while they offer in return a comparatively small amount of remunerative traffic. Railways, on the other hand, have continually tended toward forms of construction involving greater cost and requiring greater income for their profitable maintenance, and have thus been almost excluded from the immediate neighborhood of many mining districts. The coal and iron mines, the products of which are bulky and give rise directly and indirectly to a vast transportation business, form exceptions to this rule. Recently, however, the attention of engineers has been called to two systems of railway construction, which put a new face upon the problems involved. The first of these is the center-rail system, illustrated in the Mont Cenis Railway, which was opened in June, 1868. This method is applicable to mountain passes which have hitherto been considered inaccessible to the locomotive; and the road just mentioned has proved that trains of passengers and goods may thus be safely carried upon gradients and curves which would have previously been considered perilous or impracticable. Up to September, 1870, its trains had run more than two hundred thousand miles, and transported between France and Italy more than one hundred thousand passengers, without injury to a single person. It cannot be claimed for this plan that the direct cost of traction is very small. On the Mont Cenis road, it is reported to have been about 97 cents per train-mile; but there were mechanical defects in the construction of the engines, which will hereafter be avoided on similar lines, and it is believed that the cost of traction can be reduced to half the above sum. Probably the best that can be expected is, that a center-rail line over a difficult country may be maintained and operated at a cost not exceeding that of the maintenance and operation of a line for ordinary engines over the same region; the latter being of course much longer. The principal saving, therefore, is in the original cost of construction; and this might be vast in amount. In fact, we may reasonably presume that ordinary road-beds would never be commercially or financially practicable in most places where the center-rail system will be used. Mr. J. B. Fell, civil engineer, read before the Liverpool meeting of the British Association a paper on the application of this system to a railway in Brazil now under construction. |