The Board inherited a vast mileage and a traffic volume, which was not likely swiftly to be enlarged, once the troops were returned, and the war shipments, which had taxed the Intercolonial, for instance, almost to its limits, for the first time in its long history, were over. All costs were at a height, which before the war, was unthinkable. Rates had not risen in comparison. The physical property was badly run down, owing to war conditions, in which connection were two especially heavy burdens, the quality and extent of which the general public could not be expected to appreciate. The life of a tie and of a wooden trestle is from seven to ten years. On the Canadian Northern, the National Transcontinental, and the Grand Trunk Pacific, there were many trestles which must be replaced either by fills or steel bridges. You would be surprised to know how many trestles there were between the Yellowhead and Prince Rupert, where it was popularly assumed that steel bridges had eliminated the old-time feature of pioneer construction. To those who are not very familiar with an important phase of railway practice, perhaps it may be explained that wooden trestles are built in places where it is intended to make entirely new and costly embankments for roadbed. But it is not done that way in the beginning, because a wooden trestle is quickly and cheaply put up, whereas, to make an embankment with, perhaps, hundreds of thousands of cubic yards of earth or rock, means the employment of innumerable teams at enormous expense, and much delay in laying rails. Sometimes, indeed, trestles are built because the character of the earth’s foundation makes it uncertain whether the first location is the best, and a trestle is adaptable to whatever slight deflection may be necessary. For several years you can use the trestles, relying on traffic developing sufficiently to pay for the embankment out of revenue. You then build it economically by work train, with the cars loaded by steam shovel and unloaded by a steampower plough, that sweeps the flat cars clean. The supersession of trestles was a large and expensive element in the Board’s work of putting the National Railways into first class operating efficiency.