The cool days of November soon compelled the boys to install a couple of heating stoves in the big building, and after that the place was warm and cheery throughout the working day, no matter how blustery and nippy the weather. At night the coals were carefully banked with ashes, to keep up a fair degree of warmth until the following morning.
Up to this time nothing had been seen of any suspicious person lurking around the premises, but one afternoon late in the month, when Tom Meeks was working alone in the hangar and John had gone to town after some bolts, Tom thought he heard a strange sound at one of the two windows near the workbench.
Turning quickly from the wing-strut which he had been setting in place, Tom faced the window just in time to see a swarthy-looking countenance, adorned with a toothbrush-like mustache, pulled out of range. The mechanic had been informed of Bob's experience with the man who had evidently followed him to the grounds during the summer, also of the blue-prints which had been stolen, and now as he observed the similarity in looks between this eavesdropper and the reported shadow of Bob, he became quite excited.
With that lack of coolness and presence of mind characterizing a more reserved temperament, the impulsive Tom rushed straight up to the window, and peered out. Of course he could see nothing, for the peeper had been cute enough upon finding himself observed to keep close to the side of the building as he moved swiftly toward its rear.
Tom now seized the lower sash and tried to throw it up, so as to get a sidewise view. To his disgust he found it double-spiked, and realized that he had put that very second nail in himself upon first learning of the loss of the blue-prints.
"Huckleberry pie!" sputtered Tom, using his favorite expression when excited.
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.