drels even managed to steal that, hoping to get possession of a peculiar and mysterious treasure in it, and Tom had considerable trouble.
Among other things he did when he had his craft, was to aid a Miss Mary Nestor, who, in her cousin's small boat, the Dot, was having trouble with the engine, and you shall hear more of Miss Nestor presently, for she and Tom became quite friendly. Events so shaped themselves that Andy Foger was glad to loan Tom the Red Streak in which to search for the stolen Arrow, and it was in the later craft that Tom, his father and Ned Newton had a most thrilling adventure.
They were on their way down the lake when, in the air overhead they saw a balloon on fire, with a man clinging to the trapeze. They managed to save the fellow's life, after a strenuous endeavor. The balloonist, John Sharp, was destined to play quite a part in Tom's life.
Mr. Sharp was more than an aeronaut—he was the inventor of an airship—that is, he had plans drawn for the more important parts, but he had struck a "snag of clouds," as he expressed it, and could not make the machine work. His falling in with Mr. Swift and his son seemed providential, for Tom and his father were at once interested in the project for navigating the upper air. They began a study of Mr. Sharp's plans, and the bal-
