He raised his machine upon its rest so that the power wheel was free of the ground. Then, to the wounded Boche's puzzled surprise, he removed the tire and fumbling in his little tool kit he took out a piece of emery cloth which he used for cleaning his plugs and platinum contact points, and bent it over the edge of the rim, binding it to the spokes with the length of insulated wire which he always carried. It was a crude and makeshift contrivance at best, but at last he succeeded, by dint of much bending and winding and tying of the pliable copper wire among the spokes of the wheel, in fastening the emery cloth over the fairly sharp rim so that it stayed in place when he started his power and in about two revolutions it cut a piece of wire with which he tested the power of his improvised mechanical file. "Often I sharpened a jackknife that way on the fly-wheel of a motor boat," he said. The Boche did not understand him, but he was quick to see the possibilities of this whirling hacksaw and he seemed to acknowledge, with as much grace as a German may, the Yankee ingenuity of his liberator. "Give me your wrist," said Tom, reaching for it; "I won't hurt it any more than I have to; here--here's a good scheme." He carefully stuffed his handkerchief around under the metal band which encircled the soldier's wrist and having thus formed a cushion to receive the pressure and protect the raw flesh, he closed his switch again and gently subjected the manacle to the revolving wheel, holding it upon the edge of the concave tire bed. If the emery cloth had extended all the way around the wheel he could have taken the manacle off in less time than it had taken Kaiser Bill to lock it on, for the contrivance rivalled a buzzsaw. As it was, he had to stop every minute or two to rearrange the worn emery cloth and bind it in place anew. But for all that he succeeded in less than fifteen minutes in working a furrow almost through the metal band so that a little careful manipulating and squeezing and pressing of it enabled him to break it and force it open. "There you are," he said, removing the handkerchief so as to get a better look at the cruel sore beneath; "didn't hurt much, did it? That's what Uncle Sam's trying to do for all the rest of you fellers--only you haven't got sense enough to know it." CHAPTER THREE THE OLD COMPASS Tom took the limping Boche, his first war prisoner, to the Red Cross station at Vivieres where they had knives and scissors and bandages and antiseptics, but nothing with which to remove Prussian manacles, and all the king's horses and all the king's men and the willing, kindly nurses there could have done little for the poor Boche if Tom Slade, alias Thatchy, had not administered his own particular kind of first aid.