The youth spent all the next day and part of the following working on the craft. He overhauled the ignition system, which was the jump-spark style, cleaned the magneto and adjusted the gasoline and compression taps so that they fitted better. Then he readjusted the rudder lines, tightening them on the steering wheel, and looked over the piping from the gasoline tank.
The tank was in the forward compartment, and, upon inspecting this, the lad concluded to change the plan by which the big galvanized iron box was held in place. He took out the old wooden braces and set them closer together, putting in a few new ones.
"The tank will not vibrate so when I'm going at full speed," he explained to his father.
"Is that where the strange man was tampering with the lock the day of the auction?" asked Mr. Swift.
"Yes, but I don't see what he could want in this compartment, do you dad?"
The inventor got into the boat and looked carefully into the rather dark space where the tank fitted. He went over every inch of it, and, pointing to one of the thick wooden blocks that supported the tank, asked:
"Did you bore that hole in there, Tom?"
"No, it was there before I touched the braces. But it isn't a hole, or rather, someone bored it and stopped it up again. It doesn't weaken the brace any."
"No, I suppose not. I was just wondering whether that was one of the new blocks or an old one."
"Oh, an old one. I'm going to paint them, too, so in case the water leaks in or the gasoline leaks out the wood won't be affected. A gasoline tank should vibrate as little as possible, if you don't want it to leak. I guess I'll paint the whole interior of this compartment white, then I can see away into the far corners of it."