"Contact!" cried the young inventor.
Jackson gave the blades a quarter pull, and, a moment later, as he leaped back out of the way, they began to revolve with the swiftness of light. There was the familiar rush of air as the wooden wings cut through the atmosphere, but there was scarcely any noise. Mr. Damon could hardly believe his ears.
"I'm not running her at full speed," said Tom. "If I did she'd tear loose from the holding blocks. But you can see what little racket she makes."
"Bless my fountain pen!" cried Mr. Damon. "You are right, Tom Swift! Why, I can hear you talk almost as easily as if no engine were going. And I don't have to shout my head off, either."
This was perfectly true. Tom could converse with Mr. Damon in almost ordinary tones. The exhaust from the motor was nearly completely muffled.
"Out in the air it will seem even more quiet," said Tom. "I'll soon give you a chance to verify that statement."
He ran the engine a little longer, the aeroplane quivering with the vibrations, but remaining almost silent.
"I'm anxious to see what she'll do when in motion," said Tom, as he shut off the gas and spark.
Soon after supper, when the shades of evening were falling, he and Mr. Damon took their places in the first of the Air Scouts, to give it the preliminary test in actual flying.
Would Tom's hopes be justified or would he be disappointed?