"Three hundred pounds pressure," he muttered, glancing at the steam indicator. "That ought to be enough. Are you all ready, boys?"
"All ready!" cried Jack.
Of course the test was only one to see if the engine worked, for the boat could not move until in the water.
The professor opened a valve. The steam filled the turbine with a hiss and throb. The Porpoise trembled. Then, with a cough and splutter of the exhaust pipes, the engine started. Slowly it went at first, but, as the professor admitted more steam, it revolved the long screw until it fairly hummed in the shaft.
"Hurrah! It works!" cried Mark.
"It does!" chimed in Jack.
"Gollyation! She suttinly am goin'!" yelled Washington.
"I think we may say it is a success," said the professor calmly, yet there was a note of exultation in his voice.
"Now that you've got her started, when are you goin' to put her in the water an' scoot along under the waves?" asked Andy Sudds.
"In about a week," replied the professor.