So intent was Garwood on what he was doing that he appeared not to have heard the approach of the boys.

d.i.c.k Prescott stood looking on, one hand raised as a signal for the silence of those behind him. But both Dave and Tom had caught sight of the stranger at about the same instant.

"If any who know me have hinted that my brain is not strong enough,"

muttered Garwood, whose back was turned to the startled Grammar School boys, "there is bound to be a great awakening when my wonderful invention is perfected. Then the world will bow down to me, for I shall be its master."

"Crazy as a porous plaster!" muttered Tom Reade under his breath.

"It will be a new, a strange sensation," continued Garwood, speaking just loud enough to be heard by the onlookers. "A great sensation, too, to be master of the world when, during these present dark days, I am compelled to run and hide for fear envious scientists will succeed in capturing me and locking me up."

"I wonder what he thinks he's doing there?" pondered d.i.c.k curiously.

"To think that a few grains of this wonderful substance would pulverize a regiment!" continued Garwood, in an inventor's ecstasy.

"An ounce of this wonderful material enough to blow up an army corps. A single pound sufficient to bring the nations of the world to my feet in awed homage. And I can make a hundred pounds a day of it! Oh, that I could reach other worlds, to make them feel my mastery!"

"If his stuff is as good as he thinks it is, I certainly hope he won't shoot off any of it accidentally," thought Prescott, with an odd little shiver.

"Oh, that I dared trust my secret to one or two others!" murmured Garwood, as he delved with one hand into one of the boxes that supported his simple bench. "And now for the great finishing touch!"

Amos Garwood placed on the board a fairsized wide-mouthed bottle.

From where he stood, d.i.c.k could read the label on the bottle--- "Pota.s.sium Chlorate---crystals."

"Chlorate of potash?" thought d.i.c.k. "That's what Dr. Bentley gave me once for sore throat."

d.i.c.k, however, was soon to get an inkling of a suspicion that chlorate of potash might be used to serve other purposes.

As the mentally queer inventor reached into the box for that bottle, the three silent, observing "Injuns" saw that Garwood had on the crude table before him a gla.s.s mortar and pestle, the former of about two quarts' capacity.

In this mortar lay a quant.i.ty of powdered stuff, which Garwood had evidently been grinding before their arrival. Now he poured out a heaping handful of the chlorate crystals, dropping them on top of the mixture in the mortar.

"A few turns---a little more fatigue of the wrist---and I am the world's master---its owner!" cried Garwood exultantly.

"Ker-choo!" sneezed Tom Reade at the worst possible moment.

Amos Garwood turned like a flash, tottering to his feet.

"Spies! Traitors! Ingrates!" he gasped in hoa.r.s.e terror.

"Nothing at all like it," d.i.c.k replied, with a pleasant smile.

"Mr. Garwood, we boys are playing in these woods. If we've meddled with your affairs you'll pardon us, and let us pa.s.s on, won't you?"

"Didn't you try to find me here?" demanded Garwood, suspicious still.

"I give you my word of honor that we didn't, sir," answered d.i.c.k.

"Until a moment ago we hadn't any idea that you were within fifty miles of this spot. You see, sir, we're playing Indians and whites. We're the big Injuns, even if we don't look it.

And behind us, somewhere on our trail, is Captain Greg Holmes, with a company of his brave soldiers, trailing us relentlessly."

"Soldiers?" quivered Amos Garwood, his face going ashen. Then his face suddenly took on a look of intense exultation. "Soldiers?"

he repeated. "It couldn't be better. It is on soldiers that my amazing discovery should be proved. But I waste time---and loss of time may be fatal to all my plans. A few turns, and my discovery is ready. I can then defy whole armies, if necessary!"

Sweeping the mortar around within reach, so that he could work and watch the Grammar School boys at the same time, Amos Garwood began to grind his pestle into the mixture with feverish energy.

Then all of a sudden the very earth shook and rocked. Big Injun Prescott and his two braves were in the center of the biggest explosion they had ever heard!

Chapter XIV

"CRAZY AS A POROUS PLASTER"

It was terrific, and yet the only effect on the bench on which the mortar lay was to knock the board sideways from the boxes.

The mortar became as powder itself, though not a splinter was raised from the wood.

From the lips of Amos Garwood a fearful yell went up. He plunged headlong a few feet, then lay on the ground, feebly nursing his right hand with his left.

As for d.i.c.k, Dave and Tom, their ears rang with the noise until they felt as though surely their ear-drums had been ruptured by the force of that awesome detonation.

An instant later all was quiet. d.i.c.k and his chums speedily realized that they had escaped actual injury, yet their legs shook so that they could hardly stand.

"Wh---wh---what was it?" asked Reade in accents that quivered in unison with his trembling legs.

"See here, fellows, we mustn't be fools," d.i.c.k cried chidingly.

"We're not hurt, and Mr. Garwood is. Let's see what we can do for him."

"Do for me, will you?" groaned the injured one. "No, you won't.

You boys keep your distance from me, or you're going to be worse scared than you are already. Don't imagine that I'm helpless, for I'm not. In me you behold the master of the world!"

"Confound him, I've a good mind to go away and let him have the world to himself," muttered Reade.

But d.i.c.k and Dave had already started toward the spot where Amos lay. The man scrambled to his feet, the old, hunted look coming into his eyes.

"You keep away from me!" he screamed. "Get away! Clear out!

I don't want to hurt you. I wouldn't harm a fly. But I'm not going to allow any one near me!"

d.i.c.k ventured too near. Garwood swung his uninjured arm so unexpectedly that Prescott had no chance to get out of the way.

He fell flat on the ground. Warned by the light in the eye of the world's master, d.i.c.k believed it prudent to roll several yards before be tried to get up.

"Say," blazed Darrin indignantly. "Are you going to stand for that?"

"Don't excite him," murmured Prescott in an undertone. "The poor fellow isn't responsible for what he's doing. And I'd fight, too, if I thought any one was trying to seize me."

"I'm sorry if I had to hurt you," said Amos Garwood in a milder tone.

"But I allow no one to come near me. I have too many enemies ---so many who are jealous of me that I can trust no one."

"He isn't really dangerous, poor fellow," whispered Prescott to his companions.

"No, though he has a habit of blowing up suddenly," muttered Reade.