The very suggestion caused our hero to hold his breath. It was not that he was frightened by the mass of machinery; it was merely the novelty of the work. He stepped a pace or two nearer before he answered, and watched closely what happened. A young American, only a few years older than himself, sat on a seat beside the gigantic main beam of the digger, his head within a few inches of the flying gear wheels which transmitted movement, while right beside him, fixed to the base of the steel-girded beam, was the engine. One hand was on the throttle, while the other operated a lever. Down came the huge bucket attached to the secondary beam, the chains which supported it clanking over their stout metal pulleys; then the hand operating the lever moved ever so little, the chains tautened, and the hardened-steel cutting lip of the digger bit into the bank which was being excavated. Deeper and deeper it went. Glug! glug! glug! the machine grunted, while the tip of the main steel girder, where the hauling chains passed over it, bent downwards ever so little. A shower of broken earth burst over the edge of the digger, a faint column of dust blew into the air, while the engine gave forth another discordant glug. Then up came the huge bucket, crammed to the very top with debris, the whole machine shuddering as the strain was suddenly taken off it. But the man remained as composed as ever. He touched another lever, causing the apparatus to swing round on its axis. Almost instantly a movement from his other hand released the trigger holding the bottom of the huge earth receptacle in place, so that, before the machine had actually finished swinging, the huge mouth of this wonderful invention was disgorging its contents into a dirt car alongside. "Fine!" cried Jim delightedly. "That's a job I should like immensely, but I guess it requires a little training." "Practice, just practice," smiled Phineas. "See here, Jim; this arm of mine has started in aching again. How'd you care to stay along here and have a lesson? That young chap's a friend of mine, so there'll be no difficulty about the matter." It may be imagined that Jim eagerly accepted the offer. He was keen enough to accompany Phineas on his promised trip right along the canal works, but already the sight of all that was happening round about Gatun had been sufficient for one day, while the huge machine before him and its cool and unruffled operator fascinated him. "Gee! nothing I'd like better," he cried. "Then come along." Phineas at once went close up to the machine, and at a signal from him the operator brought it to a rest. "Howdy?" asked the young fellow. "Getting in at it, Mr. Barton?"