A little further on, they came upon a myriad of tanks of all descriptions. There were "baby" tanks, "whippets," "male" and "female," all with different functions to perform during a battle. Just as in the navy there are vessels of all sizes from a light scout to a super-dreadnought, so already this arm of the service was developing various grades, each to do some special work for which the others were not so well adapted. "See how they're hidden," said Frank, as he pointed to a very forest of bushes and branches that extended above the array of tanks. "That's to keep the Boche aviators guessing," observed Bart. "They'd give their eyes if they could only spy out where these fellows are being massed." "I heard one of the fellows say that the tanks travel only at night so that the Boches can't track them," said Tom. "And see what a raft of them have been got together here," said Billy. "I tell you, fellows, there's something big going to be pulled off before long." "Say, boys, see who's here!" exclaimed Frank, and they turned to see Will Stone coming toward them with a broad smile of welcome on his bronzed face. CHAPTER XII BREAKING THROUGH There was a rush toward Will Stone, and in a moment the Army boys were shaking hands with a vigor that showed the pleasure they felt at again meeting their acquaintance, who belonged to the tank division. "Say, fellows, have a heart," Will grinned. "I need these hands in my business. But it sure does me good to see you again. And all of you alive and kicking! I'll bet that's more than some of the Huns are that you've run up against." "Oh, we're still able to sit up and take nourishment," laughed Frank. "But tell us about yourself, old man. You look like ready money." "I see you have a marking different from what you had when we saw you last," remarked Bart, looking at the insignia that proclaimed Will an officer. "And look at that war cross!" cried Tom. "I guess you've been some busy little bee to get that. Shake again, old scout." Stone flushed and looked a little embarrassed. "Only a few little skirmishes here and there," he said deprecatingly. "But the real big thing is yet to come. Look at this army of tanks. We've never had so many in one place since the war began." "Looks like a herd of elephants," commented Frank, as his eye ran along the array that seemed to number hundreds. "They'll do more trampling than any herd of elephants that ever trod the earth," remarked Stone grimly. "But come along, fellows, and let me show you my own particular pet. It's the biggest one of the bunch, and it's a peach! We call it Jumbo, and it carries a crew of twenty men." They followed him till they came to a monster tank on which Stone placed his hand caressingly. "Isn't it a beauty?" he asked, as he beamed upon them. "I should call it a holy terror," grinned Frank. "What the Huns will call it won't be fit for publication," laughed Billy.