"Look out, look out, here we go!" cried Nat, although there was not the slightest use for such a remark. "Say, be careful about canal-boats; there are some fast ones on this line." The "Nimrod" was put in motion, and swept speedily forward. Bob started the "Rambler." "Nat has a fine boat," he declared; "but ours is better." "I wish they hadn't come along," commented Sam Randall. "I'll wager we are in for some lively times." "Well, I, for one, propose that we don't stand any nonsense," exclaimed Dick Travers. "Give that crowd a chance, and—" "Hey there, old slow-pokes, are you moving or standing still?" shouted Nat. "You need help." "So will you, if you keep that up," retorted Dick, who was not so disposed to be good-natured as his companions. The motor boats were dashing along at full speed in midstream, when the "Nimrod," which was easily distancing its competitor, slowed down and allowed the other to approach. "Shut off your power, back there in the tub!" shouted Nat, authoritatively. "Now mind what I say, or there's going to be trouble." Deliberately, he swung his boat around, so that the hull was presented broadside to the rapidly approaching "Rambler." "Look out! What are you trying to do?" came in a chorus from the latter boat. It seemed as though the Nimrods were absolutely regardless of consequences. Quick as a flash, Bob shut off the power and jammed the wheel far around. Thus suddenly swerved from its course, the motor boat careened far over, and just grazed the side of the "Nimrod," which was now scarcely moving. Before any of the Ramblers could divine his intention, Nat Wingate quickly passed a stout rope through an iron ring at the bow of their boat. "Go ahead, Kirk—full speed!" he shouted. Darting forward, the "Nimrod" suddenly pulled the line taut with a force that jarred the "Rambler" from stem to stern. "We've turned pirates!" yelled Nat. "Whoop la, oh ho, this is our first catch." And his companions joined in a hearty laugh. It was not until the "Rambler" had swung around and