“I shouldn’t think they’d sell that stuff to a boy,” said Helen.
“It isn’t everybody who takes me for a child,” said Chap, loftily, and made no further remarks on the subject.
“But how are you going to get the treasure?” asked Helen, presently. “Won’t it be scattered all over, in every direction?”
“Now, look here, Helen,” said Chap, “I don’t want you to be making objections. I didn’t let you into this thing for that purpose. I’ve put the powder on the outside of the wreck, and it’s my opinion that most everything will be blown in shore. If the money is stowed away in iron boxes, perhaps they’ll come down without breaking. But we can’t calculate for everything. The main thing is to blow her up.”
Soon after this the two arrived at their destination, and, uncovering his battery, Chap exhibited it to his sister, and explained its action.
One of the wires which came from the jar which contained his simple battery he united to the end of one of his wires from the river. The end of the other wire was laid on a small board which covered one end of the box, and was held in position by two wooden pegs. Directly over this end of the wire was the end of the other short wire which came from the battery, and which was fastened under a little wooden spring, which Chap had made, and to the top of which he had fixed a small knob or button.
“Now, Helen,” said Chap, when everything had been made ready, “you can see just how the thing will work. When you press that knob, and push the spring down, the two ends of the wires will touch, and the electric circuit will be complete. These wires, which are insulated by being covered with tape dipped in paraffine, except these upper ends, which don’t need insulating, as they lie on wood, which is a non-conductor, extend from the battery down to the giant-powder at the bottom of the river. The two ends which are in the powder are united by a little piece of thin platinum wire. When the circuit is completed by pressing down the wire fastened to the spring, the electricity runs along one wire, to come back by the other, but when it reaches the little platinum wire it makes it red-hot, and that explodes the powder. So, you see, it is all simple enough.”
“Yes,” said Helen, a little hesitatingly, “but you must have studied a good deal to understand it all, and these things must have cost a good deal of money, too.”
“I don’t mind expending time or capital,” said Chap, “when I am going to do anything of importance. And now I think everything is ready.”
He then ran to a fence near by, and got up on the top rails, from which he could get a view of the river for some distance up and down. Jumping to the ground, he hastened back to Helen.