RAILWAY CONSTRUCTION. 185 



were of immense service for the transportation of heavy 

 materials, and without their adventitious aid many valuable 

 collieries and quarries must long have remained idle and unde- 

 veloped. In thus providing a level, smooth, and comparatively 

 durable wheel-track for the waggons, -these tramways became 

 the fitting pioneers of the great railway system which was 

 to follow. 



Notwithstanding the great superiority of the cast-iron plates 

 as compared with the former timber beams, much inconvenience 

 was still caused by gravel and dirt falling on to the wheel-track 

 and seriously impeding the haulage of the waggons. To over- 

 come this difficulty the next step taken was to remove the 

 guiding flange from the tram-plate and transfer it to the wheel, 

 thus developing and introducing the original flanged wheel. 

 This was a most important step, and paved the way for other 

 improvements. The rails, or edge rails, as they were at first 

 called, were made sufficiently high to allow ample space for 

 the wheel-flanges to clear the ground, and were secured to 

 cast-iron chairs placed on wooden cross-sleepers, or in some 

 cases to stone blocks, as shown in Figs. 233, 234, and 235. 

 The narrow top of rail, and its height above the horse-path, 

 effectually prevented the lodgment of gravel or dirt, and the 

 flanges on the wheels ensured a more even course. From the 

 irregular and easily choked-up tram-plate, the system changed 

 to the clean rail and properly defined track. Waggons could 

 be hauled with greater freedom, and with less wear and tear 

 to themselves and to the roadway. 



At this time the use of the steam-engine was becoming more 

 general, and a fine field was opened out for its application 

 as a motive-power on the tramways. Stationary engines, or 

 winding engines, as they were called, were first employed to 

 haul the trucks by means of long ropes passed round revolving 

 drums, and supported at intervals by grooved pulleys placed 

 between the rails at suitable distances. In this way fair loads 

 could be conveyed, and at moderate cost ; but the system was 

 found to be only suitable for short distances, and it had the 

 great drawback that horses or other motive-power were still 

 necessary for sorting or distributing the trucks before and after 

 their transit by rope haulage. 



The next great advance was to place the steam-engine on 

 wheels, to enable it to haul and accompany the trucks. Crude 



