"Good!" said Mr. Giddings. "I shall await them with great interest. I suppose as soon as I approve these drawings, you fellows will all pitch into the actual work." "We surely will, sir," laughed Paul, while Bob, at the wheel in front, having caught some of the conversation, called back with energy: "That's just the size of it, dad." "We have everything all ready," continued Paul. "The balsa-wood and spruce we ordered some time ago is on hand, and that will keep us busy until other needed materials arrive. We have repaired the big exhibition building in the old fair-grounds, put on new double doors and purchased a good Yale lock for them. John and I have taken our workbench and tools over there, and Bob has helped us rig up a nice little five-horse power motor and small handsaw, also a circular saw, home-made sand-drum, a small planer, and a boring-machine. That building is dry, and has lots of room in it for housing the new airplane as it grows to maturity. When cold weather comes we can easily install a couple of heating-stoves to keep ourselves comfortable and protect our materials and the machine from frost damage." Mr. Giddings expressed himself as well pleased with these arrangements. As he noted the foresightedness of the young mechanics his confidence in them expanded. "Don't hesitate to order anything you need, young men," he said warmly. "Have them send the bills to me. If my trust in you is misplaced, I am willing to stand the consequences. This is not only the best kind of a practical education for Bob, but it is good business training for all of us. Go ahead; go ahead!" With such strong encouragement, is it any wonder that the three young men continued their operations vigorously? Not one of them scarcely wanted to stop long enough to eat and sleep, _a la_ Edison; and as it was now summer vacation time, Paul and Bob were able to be with John all day long in the old exhibition building. Neighboring boys and even older people hung around the open doors to watch operations, but the builders were careful not to let them get close enough to gain any ideas which might be harmful to their interests. On Tuesday evening of the week following the start of the Air Derby, John and his brother put on their best clothes and hied themselves over to the Giddings home. In Paul's hand was an envelope containing the precious plans for the Sky-Bird II--completed at last by the young draftsman, and ready to be shown to the financial member of the quartet. When they were all seated in the Giddings library a little later, Mr. Giddings scrutinized the plans with every evidence of satisfaction written upon his strong features. Now and then he would ask a question, as Paul explained view after view and detail after detail. At length he pointed to an oblong object situated in the pilot's cockpit just under the dashboard. "What is that?" he asked, curiously.