"I hardly think so," said Ned. "He wouldn't wait until after dark for that. This is something big, and Tom must intend to have it out in the open. He probably waited until after sunset so the neighbors wouldn't come out in flocks. There's been a lot of talk about what is going on in Shop Thirteen, especially since the arrest of the German spies, and the least hint that a test is under way would bring out a big crowd." "I suppose so," agreed Mr. Nestor. "Well, I'm glad to know that Tom is doing something for Uncle Sam, even if it's only helping with gas helmets. Those Germans are barbarians, if ever there were any, and we've got to fight them the same way they fight us! That's the only way to end the war! Now if I had my way, I'd take every German I could lay my hands on--" "Father, pretzels!" exclaimed Mary. "Eh? What's that, my dear?" "I said pretzels!" "Oh!" and Mr. Nestor's voice lost its sharpness. "That's my way of quieting father down when he gets too strenuous in his talk about the war," explained Mary. "We agreed that whenever he got excited I was to say 'pretzels' to him, and that would make him remember. We made up our little scheme after he got into an argument with a man on the train and was carried past his station." "That's right," admitted Mr. Nestor, with a laugh. "But that fellow was the most obstinate, pig-headed Dutchman that ever tackled a plate of pig's knuckles and sauerkraut, and if he had the least grain of common sense he'd--" "Pretzels!" cried Mary. "Eh? Oh, yes, my dear. I was forgetting again." There was a moment of merriment, and then, after the talk had run for a while in other and safer channels, Mr. Damon made the announcement: "I think we're about there. We'll be at Tom's place when we make the turn and--" He was interrupted by a low, heavy rumbling. "What's that?" asked Mr. Nestor. "It's getting louder--the noise," remarked Mary. "It sounds as if some big body were approaching down the road--the tramp of many feet. Can it be that troops are marching away?" "Bless my spark plug!" suddenly cried Mr. Damon. "Look!" They gazed ahead, and there, seen in the glare of the automobile headlights, was an immense, dark body approaching them from across a level field. The rumble and roar became more pronounced and the ground shook as though from an earthquake. A glaring light shone out from the ponderous moving body, and above the roar and rattle a voice called: "Out out of the way! We've lost control! Look out!" "Bless my steering wheel!" gasped Mr. Damon, "that was Tom Swift's voice! But what is he doing in that--thing?" "It must be his new invention!" exclaimed Ned. "What is it?" asked Mr. Nestor. "A giant," ventured Ned. "It's a giant machine of some sort and--"