“Humph!  They’d better not put much trust in that,” Murray grunted, grimly.

“Don’t fool yourself; it’s no rubber-tired baby-carriage,” said Slater.  “Our men are afraid of it.”

After watching the device scuttle back and forth for a few moments O’Neil said shortly: 

“Post a notice at once, offering a thousand dollars for any man who cuts that cable.”

“A thousand—­” Appleton gasped.  “Why, I’ll do it.  Let me—­”

“No, you won’t,” Slater broke in.  I’ll take that on myself.”

“I spoke first.  It’s my first chance,” Dan cried.

“It’s my job!  I’m going—­”

“Wait a minute!” O’Neil silenced the two, who were glaring at each other angrily.  “Don’t let’s have any fighting; there will be enough of that later.”

“I spoke first,” Dan repeated, stubbornly.

“I had my mouth puckered to spit, that’s why,” the fat man explained.  “A fellow has to spit—­”

“I’d rather you wouldn’t volunteer, Dan,” said O’Neil.

“Why?”

“You might get hurt.”

“Happy Tom” nodded his agreement.  “Certainly!  Never send a boy on a man’s errand.”

“And I don’t want you to do it either, Tom, for the same reason.”

Slater mumbled some sort of sour acquiescence, but Dan would not be denied.

“You made the offer, and I took it up,” he told O’Neil.  “Somebody has to make the first move, and I have a particular need for exactly one thousand dollars.  If they start a rumpus, it will give us the excuse we’re looking for.  I’ve been studying that ‘go-devil’ through field-glasses for two days now, and I’ll guarantee to put it out of commission before Gordon’s men know what I’m about.  Just forget the reward, if you like, and give me a chance.”

“What’s your plan?” Slater inquired, eagerly; but Appleton shook his head.

“No you don’t, Tommy!” he said.  “I’m wise to you.”

Murray hesitated briefly, then gave his permission.  “I’d rather you’d let one of the rough-necks take the chance, but if you insist—­”

“I do.”

“Then get your sister’s consent—­”

Slater swore mournfully, as if from a heart filled with black despair.

“Ain’t that my luck?  One cud of gum cost me a thousand dollars!  Hell!  It would take a millionaire to afford a habit like that.”  He expelled the gum violently and went grumbling off up the track.

“Sis won’t object,” said Dan, lightly.  “She’d offer to do the trick herself, for she’s getting the spirit of the work.”

When O’Neil had managed to regain the camp he began preparations for an attack that very night, using the telephone busily.  News of the coming affray quickly spread, and both the day and night shifts discussed it excitedly at supper-time.

Nor was the excitement lessened when a loaded gravel-train rolled in and Dr. Gray descended from it with his emergency kit and two helpers from the hospital at Omar.