He whirled about and started for the door of the building. On account of the extensive size of the structure it was quite a little way to this. To make matters worse Tom dashed forward in such haste and flurry that he did not watch his step very closely; when he was about half-way to the door, his toe caught the protruding leg of an innocent sawhorse, and the next moment Tom Meeks and the sawhorse were both overturned. "Huckleberry pie!" gasped the big fellow. His right shin hurt like fury, but he would not stop to examine it, and covered the remaining distance to the door in very ludicrous limping jumps. Dashing around the front of the building, he reached the corner which gave him a view of the side. Not a soul was in sight. Not to be outdone completely, Tom hurried along the side of the building. As he came near the rear end he saw a slender figure just clambering over the highboard fence of the field in the rear of the hangar. Lame as he was, big Tom knew there was no chance of his overtaking the fleet-footed and cunning stranger, so he returned to his work very much crestfallen in spirit. When John heard what had happened, on his return to work, he was considerably disturbed, and suggested to his comrades the advisability of placing a night-guard on the premises for a while at least, since this unknown enemy might make an effort some night to burn or irreparably damage the Sky-Bird. The others sanctioned this precaution, and thereafter took turns in watching, although this vigilance was apparently all for naught, as no suspicious character appeared. CHAPTER VIII THE SKY-BIRD II "Well, Mr. Giddings, what do you think of Sky-Bird II?" asked John Ross, one memorable day. There was a smile of deep satisfaction on John's own bronzed features as he put the question, a smile which was duplicated on the faces of his three co-workers--Paul, Bob, and Tom Meeks. It was the latter part of March, Easter vacation week for Paul and Bob, and the two chums had been working every one of the last three days helping John and Tom put the finishing touches on the big new airplane. And now this Friday morning it rested gracefully upon its own rubber-tired wheels, its great stretch of wings spread out as airily as those of a monster bird, its huge two-bladed propeller glistening like burnished silver, and its body running backward in a splendid symmetrical taper, to end at the well-proportioned tail. Sky-Bird II was done at last. Mr. Giddings was so lost in admiration at the beautiful lines of the craft that he did not reply immediately to John's question. He had not seen it for almost two weeks, and in that time, under the onslaughts of the four boys, it had changed appearance in a striking way, numerous finished parts having been connected and paint and varnish having been applied.