operated with perfect smoothness, and the speed was normal and perfectly sustained, but when Mr. Sharp looked at the voltmeter of his generator, there was another story to tell. The meter showed no voltage whatever. There was an open circuit either in the generator or in the field.
At once the chief electrician attempted to adjust the field strength by shifting the field rheostat. To his surprise he found the handle of the rheostat was warm.
“The rheostat is burned out,” he said, “and there is likely an open field circuit.”
“Then one of the field coils must have gone bad,” said Henry.
“Right. I see you do know something about wireless,’ observed the chief electrician.
Henry reached forward and began to examine the field coils. There were four of them. The bottom one and the two on the sides were warm, but the top coil was cool.
“Here it is!” cried Henry.
The chief electrician rapidly ran his hand over the coils and verified Henry’s findings. “We’ll take it off,” he said, “and put a new one in its place.”
Skillfully he set to work. It required care and deft handling, but he soon had the defective coil removed and a new one set in its place. Then he turned to the rheostat, which had been