Jack Benson stole below on tip-toe, though with the machinery running so much stealth was not necessary.  Right behind him followed Hal.

As the two gained the doorway of the engine room Sam Truax had his back turned to them, and so did not note the sudden watchers.

There was a smile of malicious triumph on Truax’s face as he turned a lever a little way over, thus decreasing the ignition power of the motors.

Both Jack and Hal could see that the gasoline flow had been turned on nearly to the full capacity.  It was the poor ignition work that was making the motors respond so badly.  A little less, and a little less, of the electric spark that burned the gasoline and air mixture—­that was the secret of the gradually decreasing speed, while all the time it looked as though the “Farnum” was doing her level best to win the race.

Whistling, as he bent over, Sam Truax caught up a long, slender steel bar.  With this he stepped forward, intent upon his next wicked step.

“Gracious!  The scoundrel is going to run that bar in between the moving parts of the engine and bring about a break-down!” quivered Hal.

Sam Truax stood watching for his chance to thrust the steel bar in just where it would inflict the most damage.  Then raising the bar quickly, he poised for the blow.

“Stop that, you infernal sneak!” roared Jack Benson, bounding into the engine room.

CHAPTER XVI:  BRAVING NOTHING BUT A SNEAK

“You—­here?” hissed Truax, wheeling about.

He had not had time to make the thrust with the steel bar.

Instead, as he wheeled, he raised it above his head, drawing back in an attitude of guard.

As he did so, a vile oath escaped Truax’s lips.

“Put that bar down!” commanded Jack Benson, standing unflinchingly before the angry rascal.

“I’ll put it down on your head, if you don’t get out of here!” snarled the wretch.

“Put it down, and consider yourself off duty here, for good and all,” insisted Jack.

“Are you going to get out of here, or shall I brain you?” screamed Truax, his face working in the height of his passion.

“Neither,” retorted Captain Jack, coolly.  “I command here, and you know it.  Put that bar down, and leave the engine room.”

“Come and take the bar from me—­if you dare!” taunted the fellow, a more wicked gleam flashing in his eyes.

“Hal!” called Jack, sharply.

“Aye!”

“Call two or three of the cadets down here.  Don’t make any noise about it.”

This order was called without Benson’s turning his head.  He still stood facing the sneak while Hal sped away.

“Now, I’ve got you alone!” gloated Truax.  “I’ll finish you!”

A scornful smile curled Jack’s lips as he gazed steadily back at his foe.

“Truax, you’re a coward, as well as a sneak.”