When Ned had gone Tom got out pencil and paper, and was busily engaged
in making some intricate calculations. He drew odd little sketches on
the margin of the sheet, and then wrote out a list of the things he
would need to construct the new aeroplane.

This finished, he went to Mr. Jackson, the engineer, and asked him to
get the various things together, and to have them put in the special
shop where Tom did most of his work.

"I want to get the machine together as soon as I can," he remarked to
the engineer, "for it will need to be given a good tryout before I enter
in the race, and I may find that I'll have to make several changes in
it."

Mr. Jackson promised to attend to the matter right away, and then Tom
went in to talk to his father about the motor that was to whirl the
propeller of the new air craft.

Mr. Swift had improved very much in the past few days, and though Dr.
Gladby said he was far from being well, the physician declared there was
no reason why he should not do some inventive work.

He and Tom were deep in an argument of gasoline motors, discussing the
best manner of attaching the fins to the cylinders to make them
air-cooled, when a voice sounded outside, the voice of Eradicate:

"Heah! Whar yo' goin'?" demanded the colored man. "Whar yo' goin'?"

"Somebody's out in the garden!" exclaimed Tom, jumping up suddenly.