at the scanty supply they had brought in with them. "Let's have a hunt for it."
"Let Rad do that, while we work on the stone gate," proposed the young inventor. "Rad, chase off and see if you can find some water."
While the colored man was gone, Tom, Ned and Mr. Damon went back to the stone gate. To attack it without tools, or some powerful blasting powder seemed useless, but their case was desperate and they knew they must do something.
"We'll try chipping away the stone at the base," suggested Tom. "It isn't a very hard rock, in fact it's a sort of soft marble, or white sand stone, and we may be able to cut out a way under the slab door with our knifes."
Fortunately they had knives with big, strong blades, and as Tom had said, the stone was comparatively soft. But, after several hours' work they only had a small depression under the stone door.
"At this rate it will take a month," sighed Ned.
"Say!" cried Tom, "we're foolish. "We should try to cut through the stone slab itself. It can't be so very thick. And another thing, I'm going to play the flames from the gas torches on the stone. The fire will make it brittle and it will chip off easier."
This was so, but even with that advantage they
