“Bless my modesty!” snorted Mr. Damon unbelievingly. “Hear Tom Swift talk about flivvering! That’s one thing he’s never done yet.”

“There’s got to be a first time for everything,” bantered Tom.

“It’ll be a long time coming,” retorted Mr. Damon. “One thing I’m certain of,” he went on; “and that is you’ll have a mighty fine market for your invention when you get it perfected. You’ll have all the big companies bidding against each other to get hold of it. I tell you, my boy, there’ll be a fortune in it.”

“Let’s hope so,” said Tom. “But the pot of gold is still at the foot of the rainbow and it may be a long tramp until I reach it.”

Although Tom expressed himself in this cautious way, he felt quite certain in his own heart that he had hit upon a great invention. This concerned itself with the drill with its sharp cutting edge, or bit. Up to that time dependence had been placed upon having a hard tempered edge that cut into and splintered the rock by its sharpness, its weight and the distance from which it fell.

This was much. But Tom’s theory was that where there was much there could always be added more. Suppose a circular motion could be given to the bit at the moment of contact and the bit itself so shaped that in addition to the crushing power given by the weight and fall there would be a grinding, scooping movement that would eat into the very heart of the soil or rock, making each stroke vastly more efficient. If he could double its effectiveness, he would wipe out at once half the time required, half the wear and tear on the machinery, half the man power required, and vastly reduce the overhead expense. It would mean an incalculable saving to the oil industry, and to Tom himself it would mean a fortune.

His father agreed with him that he had hit upon an idea that went to the core of the matter. Then followed long days and nights of experimenting, until at last just as the dawn was lighting up the sky on one memorable morning Tom leaped from his seat in wild exultation and fairly shouted:

“I’ve got it! I’ve got it!”

After the first few minutes of jubilation, he went over his figures and diagrams again. Yes, if there was anything in mathematics, he had proved that the new drill and bit would do what was expected of them.

But the invention had first to be demonstrated in actual working, and he pushed forward energetically the work in his experimental plant.