As has been said, the real test of an aviator’s skill is not in sailing through the air where all is tranquil, but in starting and in landing. Professor Sperbeck had left the ground without the least difficulty and he now came down with the grace and lightness of a bird.

In the afternoon Harvey Hamilton resumed his lessons, the instructor complimenting his proficiency.

“If the conditions are favorable to-morrow, we shall leave the ground with you at the helm,” he assured his pupil, when they gave over the attempts for the day. At the side of the field nearest the house, Mr. Hamilton had had a hangar built into which the aeroplane was run and the door carefully locked. It was natural that the neighbors should show much curiosity in the contrivance, and there was no saying what mischief they might do. Bohunkus felt so much concern on this point that he came over to his friend’s home after the evening meal and joined them on the porch, where Mr. Hamilton was also seated.

“I think,” said Bunk, “that we hadn’t oughter leave dat airyplane by itself.”

“We haven’t,” replied Harvey; “the building is strong and the door locked.”

“But some folks mought bust off de lock and run off wid it; some ob dem people am mighty jealous ob me and yo’, Harv.”

“They are all good friends of ours,” remarked the merchant; “I’m sure nothing is to be feared from them.”

“I hopes not, but I feels oneasy.”

“What would you suggest?”

“Dat some one keeps watch all night.”