And the interminable circling kept on. It seemed hours that they rode thus, using up their precious gas in this ridiculous, passengerless flight. Finally Hal crawled out of the cockpit and crept to the front of the wing. He risked thrusting a hand gingerly down in the back of the engine. Finally his searching fingers closed over the obstruction, a slick, bottle-shaped thing with a greasy pointed neck. It was their can of motor oil, carried for emergencies, and it had jarred under the throttle-arm and wedged. Hal tugged and pulled but the grease-covered can seemed to offer no grip for his fingers. He reached in for a closer grasp, set his teeth, and yanked. The obstruction gave, zipped out with such momentum that the force of Hal’s pull nearly shot him backwards off the plane edge. The can spun a thousand feet down through space. Rather white around the mouth, Hal slid back into the safety of the pit.

With a freed throttle, Maben made a landing with all of his usual ease and grace. But there was no one to watch him. The little crowd that their ruse of the diving dummy had assembled for them had long since departed.

So far as barnstorming aviation was concerned, East Texas seemed to be a total loss. Hal and Maben swooped down to their camp, gathered up their very limited assortment of housekeeping necessities, and set wing for further westward.

Within the week they hit a line of carnivals and country fairs.

With so much competition in the way of stunt flyers and aerial circuses, any newcomer on the scene must think up something out of the ordinary if he expected to make a living with his sky bus. And with necessity fostering invention, Hal’s brain conjured up the something.

Even on these little half-mile country tracks, the auto racer was replacing the old-time horse racer. Hal’s agile imagination leaped a step further. Why not race car against airplane? The one on the ground, the one in the air, but both racing in the same limited circle in full view of the grandstand?

It was so revolutionary an idea that at first no one would listen to him. A laugh in the face was all he got for his explanations of how to manage this new thrill-offering.

Then the manager of the lively carnival in swing at Repton caught Hal’s vision. On his track was staged their first auto-aero race. There was a spice of danger to the thing—at least for the aerial part of it. To speed a plane in a little half-mile circuit takes a master hand at the stick. But Maben had that master hand. He could make a sky bus do almost anything in reason.

Above the tiny circuit of the dirt track he had to bank his old plane pretty nearly straight up and down and zoom around like a bee in a bottle. To keep from winning too soon and ruining the show, he had to throttle down her motor until the last lap. Then he’d let the sky bus out and show the boys what she could do. Below him the begoggled auto speed-fiend would let his ground ship out too and smoke his wheels on turns, but the sky bus always won.

The auto-aero race was a success, a wow! It caught the fancy of the crowds and gave them more thrills than they knew were left in this thrill-worn universe. The air-earth races kept the Repton Fair open a week longer than had been counted upon. After its closing, Hal and Maben drifted on to other fairs and found good money waiting for them almost everywhere they touched. Sometimes they took in twenty-five dollars a day, but more often it was seventy-five, and now and again they reached the hundred mark.