The contestants were fully advised as to the rules of the race. The course was laid along the shore of the lake and described a complete semi-circle seventy miles in length. The turning point was at Grand Bay. All along the course men were posted to watch out for any deviation exceeding two miles from the shore line of the lake. At Grand Bay it was a straight away course back to the International grounds.

The Whirlwind came out with Valdec in the seat sneering and arrogant as usual. A youth about the age of Hiram occupied the cockpit. The machines were thus evenly matched. There were eighteen other entrants for the event.

“There’re some pretty good machines in the race, Dave,” his assistant remarked as they awaited the starting signal.

“I see that,” replied the pilot of the Ariel. “We mustn’t miss a point, or lose a yard, on turns or drifting. Is everything all right?”

“As right as could be,” answered Hiram buoyantly. “What’s the programme, a rush?”

“Not at the start. We won’t risk any mix up. Let the others, particularly the Whirlwind, catch a gait. Then we’ll strike the higher level and get a clear course, if we’re lucky enough to outdistance the others.”

The start was very fine. It resembled the progress of a flock of birds trying their wings after a rest. Mr. Brackett looked greatly pleased as the Ariel did just what it had been built to do—rose lightly, made smooth upward progress and showed itself to be a very superior model of grace and efficiency.

“Oh, dear! over two hours’ blind waiting,” sighed Bruce, as the aerial fleet spread out, and grew less distinct, so that, even with a field glass, it was difficult to distinguish one machine from another.

“There’s a breakdown!” Hiram announced, just as they passed the first observation station on the lake shore.

It was number six, a rather poor craft, and Dave could tell from its maneuvers that some of its gearing had gone wrong.