"It's the only way to do the business," explained Phineas. "The getting away of those spoil trains means the success of our working. If they don't get clear, so as to be back at the earliest moment, there's going to be any number of steam diggers thrown out of work; for it's no use shovelling dirt if there aren't cars to load the stuff in. If there's a breakdown with one of the cars, guess the whole labour force is pushed on to it, so as to get the lines clear. Telephone wires run up and down the line, and a breakdown is at once reported. But we're just entering the cut, and in a little while you'll be able to see and understand everything."
To be accurate, it took our hero quite a little while to grasp the significance of all that he saw, for the Culebra cut extends through nine miles of rocky soil, and at the period of his inspection it had already bitten deep into the hilly ground which barred the onward progress of the canal at Obispo. One ought to say, in an endeavour to give facts accurately, that this mass of material forms the southern boundary of the huge Chagres valley which, when the works are completed, will be flooded with water. It bars all exit there, though by turning sharply to the left one may follow the course of the river through a narrow, ascending valley. However, the scheme of the undertaking required that there should be no sharp bends, and in consequence the host of workers were toiling to cut a gigantic trench, of great width and enormous depth, right through this hilly ground. What Jim saw was somewhat similar to the works below Gatun, at the Colon end of the canal, but vastly magnified. There were the same terraces, with tracks of rails laid, bearing an endless procession of spoil trains and numbers of steam diggers. There was the same pilot cut in the very centre, from which the terraces ascended step by step, as if they were portions of another Egyptian pyramid. But there comparisons ceased. This huge ditch extended for nine miles, and throughout its length presented an army of toilers, any number of dirt trains, and a constant succession of white steam billows, at various elevations, pointing to the places where the hundred-ton diggers were at work.