They came at length to this far-famed range of lofty hills which link the Andes of South and Central America. Leaving the train, Naughton tramped ahead toward the gigantic gash dug in the continental divide. Clouds of gray smoke spurted from far below, and the earth trembled to one booming shock after another. Dynamite was rending the rock and clay, and Walter realized, with a little thrill of pride, that he had been really helping to build the Panama Canal. Presently he stood at the brink of this tremendous chasm. It seemed inadequate to call it a "cut." He gazed down with absorbed fascination at the maze of railroad tracks, scores of them abreast, which covered the unfinished bed of the canal. Along the opposite side, clinging to excavated shelves which resembled titanic stairs, ran more tracks. Beside them toiled the steam-shovels loading the processions of waiting trains. No wonder Jack Devlin, engineer of "Number Twenty-six," had swaggered across the deck of the _Saragossa_. He knew that he was doing a man's work. To tame and guide one of these panting, hungry monsters was like being the master of a dragon of the fairy stories. There could be no Panama Canal without them. Intelligent, docile, tireless, they could literally remove mountains. Walter sat upon a rock and watched one of them nudge and nose a huge bowlder this way and that with its great steel dipper, exactly as if it were getting ready to make a meal of it. Then the mass was picked up, swung over a flat-car, swiftly, delicately, precisely, and the huge jaws opened to lay down the heavy morsel. Walter decided that he wanted to be a steam-shovel man. Naughton had to speak twice before the interested lad heard him say: "I shall be busy for some time, and may have to jump on a work-train as far as Pedro Miguel station. Go down into the Cut, if you like, and look around." "Thanks. Say, Mr. Naughton, how old must a man be to run a steam-shovel?" "They break them in as firemen. Are you tough enough to shovel coal all day? Don't let these Culebra tarriers coax you away from us. You are scheduled to play ball for Cristobal, understand?" By means of several sections of steep wooden stairs Walter clambered to the bottom of the cut, and dodged across the muddy area of trackage to gain the nearest bank upon which the steam-shovels were at work. Fascinated, he halted to watch one of them at closer range. A noise of shouting came from several laborers who were running along a track further up the steep slope. The nearest steam-shovels blew their whistles furiously. The shrill blasts were sounding some kind of warning and Walter said to himself: "Naughton's men must be ready to set off a blast. I guess I had better move on."