It will be observed from this table that upon the Merthyr, Tredegar and Abergavenny Branch, with its steep gradients and severe curves, the trains can only run at less than half the average speed that can, without difficulty, be maintained upon the main line, and it may be added that, while upon the main line the load drawn by a goods engine is five tons to every ton of engine, on the Merthyr Branch the load is only three tons to every ton of engine, notwithstanding the low rate of speed.
The following may be mentioned as instances of specially steep gradients for short distances:—The incline to the Fruit Market at Edge Hill, near Liverpool, is 1 in 24 for 173 lineal yards, and the load which can be drawn up it is only 2½ times the weight of the engine. On the Hopton incline, on the Cromford and High Peak Railway, there is a gradient of 1 in 14 for a length of 440 lineal yards, and on this an engine is only able to draw its own weight of load.
On the other hand, on an easy gradient, a coal engine will draw from eight to ten times its own weight, and between London and Carlisle 2½ tons of passenger train load can be drawn for every ton of engine at an average speed of from 45 to 50 miles an hour, and if this is compared with the same load conveyed over the Merthyr, Tredegar and Abergavenny Branch at a speed of only 22 miles an hour, the effect of curves and steep gradients upon the working of a railway will be seen at a glance.
Sharp and reverse curves add to the train resistance and increase the risks attending a high rate of speed,and they also largely contribute to the fatigue experienced by a passenger after a long railway journey.
To maintain the permanent way of a great passenger
