"That's better, Tom," he said. "I didn't think you could get an explosive that would successfully shatter that hard rock, but you seem to have done it. Have you the formula all worked out?"
"All worked out, Dad. I only made a small quantity, but the same proportions will hold good for the larger amounts. I'm going to start in and make it now. And then—Ho! for Peru!"
Tom struck an attitude, such as some old discoverer might have assumed, and then he hurried into the house to telephone a telegram to the Shopton office. The message was to Mr. Titus, and read:
"Explosive success. Start making it at once. Ready for Peru in month's time."
"Thirteen words," repeated Tom, as the operator called them back to him. "I hope that doesn't mean bad luck."
The experiment which Tom Swift had just brought to a successful conclusion was one of many he had conducted, extending over several wearying weeks.
As soon as Tom had received the samples of the rock he had begun to experiment. First he tried some of the explosive that was so successful in the giant cannon. As he had feared, it was not what was needed. It cracked the rock, but did not disintegrate it, and that was what was needed. The hard rock must be broken up into fragments that could be easily handled. Merely to crack it necessitated further explosions, which would only serve to split it more and perhaps wedge it fast in the tunnel.
So Tom tried different mixtures, using various chemicals, but none seemed to be just right. The trials were not without danger, either. Once, in mixing some ingredients, there was an explosion that injured one man, and blew Tom some distance away. Fortunately for him, there was an open window in the direction in which he was propelled, and he went through that, escaping with only some cuts and bruises.
Another time there was a hang-fire, and the explosive burned instead of detonating, so that one of the shops caught, and there was no little work in subduing the flames.
But Tom would not give up, and finally, after many trials, he hit on what he felt to be the right mixture. This he took out to the big lot, and having made a miniature tunnel with some of the sample rock, and having put some of the explosive in a hole bored in the big chunk Koku carried, Tom fired the charge. The result we have seen. It was a success.