By means of a small handle on the armature of the magneto it was whirled rapidly around. As soon as this was done there came a vicious spark from the end of the wire.
“Trouble is in the batteries,” said Ned.
The spark which exploded the gases in the cylinders of the Dartaway was produced in two ways. When the engine was first started it came from a series of dry cells and a spark coil. Once the fly wheel was revolving well, a switch could be turned to make the current come from the magneto, which was operated by it. But it was necessary that the fly wheel revolve swiftly before any current sufficient to operate the motor would be produced by the magneto.
Now the only way the fly wheel could be operated swiftly enough was to run the engine rapidly and this could not be done except by a spark from the batteries. So it will be seen that the motor boys were in trouble of a peculiar kind right at the start.
True, if one of them could have turned the fly wheel swiftly enough by hand to have made the magneto produce a spark, to get the explosions started the problem would have been solved, but it is doubtful if even a strong man could have performed that feat.
They tried it by turns, when Jerry had exhausted everything else he thought of, but for all their back-breaking efforts there was no result. The Dartaway belied its name.
The boys were hot and tired. The girls were nervous. It had been Jerry’s plan to get the engine started, reverse the screw, and see if he could not pull the boat from the bar. But she stuck fast.
“Shall we row the girls ashore?” asked Sammy. “It’s getting late and the folks may be worried.”
“Well, we’re sorry to lose your company,” said Jerry, “but we seem to be up against it. Maybe it would be the best thing to do. We’ll make up for this some day and give you all a better ride.”
The girls got up, preparing to leave.