"I'll not tell," promised Tom, laughing.
Preparations for the test went on rapidly. In the morning a fire was to be started in the same pit where the experiment had partly failed before.
From the platform over the blazing hole some of the new combination of chemicals was to be dropped. If it acted with success, as Tom believed it would, he proposed to go on with the more important test in the afternoon.
To this end he had purchased from a farmer the right to set on fire an old ramshackle barn, standing in the midst of a field about three miles outside of Shopton. The barn was on an untilled farm, the house having been destroyed some years before, and it was not near any other structures, so that, even in a high wind, no damage would result.
Tom had filled the barn with inflammable material, and was going to spare no effort to have the test as exhaustive as possible.
The time came for the preliminary trial, and there were a few anxious moments after the oil-soaked boards and boxes in the pit were set ablaze.
"Let her go!" cried Tom to his man on the elevated platform, and down fell the container of chemicals. It had no sooner struck and burst, letting loose a mass of flame-choking vapor, than the fire died out.
"You've struck it, Tom! You've struck it!" cried Ned.
"It begins to look so," agreed the young inventor. "But I'll not call myself out of the woods until this afternoon. Though we can consider it a success so far."
Quite a throng was on hand when the old barn was set ablaze. Tom and Ned and Mr. Damon were there with the airship which had been especially fitted to carry the bombs filled with the extinguisher.