One of the biggest of the guards shook his head.

“Try,” invited Tom.  “Take hold of the handles.  At first you will be able to let go easily.  But, when I shall move my finger though but a little, you will be held fast.  Then, another movement, and you will be loose again.  Can I do it?”

Once more the giant shook his head.

“Try,” urged Tom, and he put the two shining handles into the big palms of the giant.  The native grinned and some of his companions laughed.  Then to show how easy it was he let go.  He took hold again.

“Now!” cried Tom, and he moved his finger.

Instantly the giant leaped up into the air.  He uttered a howl that seemed to shake the very roof of the hut, and his arms were as rigid as poles.  They were drawn up in knots, and though he tried with all his great might, he could not loose his fingers from the shiny handles.  He howled in terror, and his companions murmured in amazement.

“It is as I told you!” exclaimed Tom.  “Is it enough?”

“Loose me!  Loose me!  Loose me from the terrible magic!” cried the giant, and, with a movement of his finger, Tom switched off the current from the electric battery.  Instantly the giant’s arms dropped to his side, his hands relaxed and the handles dropped clattering to the floor.

With a look of fear, and a howl of anguish, the big guard fled, but to the surprise and gratification of Tom and his friends the others seemed only amused, and they nodded in a friendly fashion to the captives.  They all pressed forward to try the battery.

One and all endeavored to loose their hands after Tom, by a movement of his forefinger, had turned the switch of the battery, and one and all of the giant guards were unable to stir, as the electricity gripped their muscles.  They were evidently awed.

“This is working better than the fireworks did,” murmured Tom.  “Now if I can only keep up the good work, and get ahead of Delby I’ll be all right.  Now for the other test, Ned.”

Ned brought from a box what looked to be a small iron bar, with a large handle on the top.  The bottom was ground very smooth.

“This is very small and light,” explained Tom, partly by signs, and partly by words.  “I can easily lift it by one finger, and to a giant it is but a feather’s weight.”

He let the giants handle it, and of course they could feel scarcely any weight at all, for it tipped the scales at only a pound.  But it was shortly to be much heavier.

“See,” went on the young inventor.  “I place the weight on the floor, and lift it easily.  Can you do it?”

The giants laughed at such a simple trick.  Tom set the iron bar down and raised it several times.  So did several of the giants.

“Now for the test!” cried Tom with a dramatic gesture.  “I shall put my magic upon you, and you shall all become as weak as babies.  You cannot lift the bar of iron!”