Of course the trailer wheels were useless in a case of this kind, and the tank had to be guided by the two belts run at varying speeds. "Here we go!" cried Tom, and the tank started. It was a queer sensation to be moving upside down, but it did not last very long. Tom steered the tank straight at the opposite wall of the ravine, where it rose steeply. One of the broad belts ran up on that side. The other was revolved in the opposite direction. Up and up, at a sickening angle, went Tank A. Slowly the tank careened, turning completely over on her longer axis, until, as Tom shut off the power, he and his friends once more found themselves standing where they belonged--on the floor of the observation tower. "Right side up with care!" quoted Ned, with a laugh. "Well, that was some stunt--believe me!" "Bless my corn plaster, I should say so!" cried Mr. Damon. "Well, I'm glad it happened," commented Tom. "It showed what she can do when she's put to it. Now we'll get out of this ditch." Slowly the tank lumbered along, proper side up now, the men in the motor room reporting that everything was all right, and that with the exception of a slight unimportant break, no damage had been done. Straight for the opposite steep side of the gully Tom directed his strange craft, and at a point where the wall of the gulch gave a good footing for the steel belts, Tank A pulled herself out and up to level ground. "Well, I'm glad that's over," remarked Ned, with a sigh of relief, as the tank waddled along a straight stretch. "And to think of having to do that same thing under heavy fire!" "That's part of the game," remarked Tom. "And don't forget that we can fire, too--or we'll be able to when I get the guns in place. They'll help to balance the machine better, too, and render her less likely to overturn." Tom considered the test a satisfactory one and, a little later, guided his tank back to the shop, where men were set to work repairing the little damage done and making some adjustments. "What's next on the program?" asked Ned of his chum one day about a week later. "Any more tests in view?" "Yes," answered Tom. "I've got the machine guns in place now. We are going to try them out and also endeavor to demolish a building and some barbed wire. Like to come along?" "I would!" cried Ned. A little later the tank was making her way over a field. Tom pointed toward a deserted factory, which had long been partly in ruins, but some of the walls of which still stood. "I'm going to bombard that," he announced, and then try to batter it down and roll over it like a Juggernaut. Are you game?" "Do your worst!" laughed Ned. "Let me man one of the machine guns!" "All right," agreed Tom. "Concentrate your fire. Make believe you're going against the Germans!" Slowly, but with resistless energy, the tank approached the ruined factory. "Are you sure there's no one in it, Tom?" "Sure! Blaze away!" Chapter XV Across Country