petroglyphs.
“This has to harden,” she explained. “Then I’ll turn the tablet over and do the other side. In the meantime, how about a little music? Bess, do you feel like playing the piano?”
“Sure.”
The young people gathered in the living room. Nancy opened her guitar case and asked who would like to play. The others insisted that she and Dave take turns.
For the next half hour they sang old songs and new. Dave amused them with an original verse.
“We’re off, we’re off
To the Forgotten City.
If we don’t find the treasure,
It’ll be a p-i-t-y!”
“I’ll say it will be,” George echoed.
Presently, Nancy left the group to return to the kitchen. She felt the paste on the tablet and decided it was hard enough to turn the rock over and “antique” the underside. This took only a few minutes. Soon she was back with the group, but kept one eye on her watch.
Exactly half an hour later, Nancy returned to the kitchen. This time the others followed and watched as she wiped off the paste. She saved it in case the stone needed another layer.
“I guess it’s done,” she said. “Now for the polishing job.”
She put a little wax on a cloth, went over the stone carefully until it matched the original. None of the “aging process” rubbed off!
“That was a great job,” Ned said to her.
The original and the new tablets were compared, and it was agreed that anyone except an expert on artifacts would be fooled by the substitution.
The boys could hardly wait for the sun to set. As soon as it did, they left. Ned carried the new tablet, wrapped in brown paper. They rode partway to the old mine, then walked the rest of the distance from the highway.
Ned was holding the package so it was prominently displayed. After a while he said, “I guess this is the right oak. Wow, it’s a whopper!”
He laid the tablet on the ground beside it; then the boys started walking back to the main road.
In the meantime, Nancy, Bess, and George had followed in Nancy’s convertible. When they reached the old road that led into the mine, Nancy started up the overgrown dirt path. She stopped the car, and they waited. There was a slight jog in the road, so the girls got out and walked ahead in order to see better.
“There’s not a sound,” Bess whispered.
Presently they spotted their friends coming from the old oak and starting along the road. Suddenly, and without any warning, a gang of boys, who apparently had been hiding behind trees, jumped the three Emerson boys and viciously started to beat them up!
CHAPTER VI
The Dangerous Hole
THOUGH taken off guard, the three football players from Emerson fought well against the attacking gang. Ned heaved one of them to the ground in a football tackle. Burt held two of them and cracked their heads together. Dave got one young gangster around the waist and pitched him off in a somersault.
Bess was screaming, “Stop! Stop!”
The hoodlums paid no attention, and the girls could see that the ratio of ten fighters to three was overwhelming.
“I’m going in there to help!” George declared, and she started forward.
Both Bess and Nancy held her back.
George struggled to get away. “I want to try some judo on a couple of those fellows!”
“Don‘t!” Bess shrieked. “They’ll—they’ll make mincemeat of you!”
Nancy said quickly, “Let me try something else first. I have a police whistle with me. It may scare them!”
She pulled the whistle from her pocket and blew a shrill blast on it. The effect was instantaneous. The attacking gang, apparently thinking the police had arrived, scattered in all directions.
Ned, Burt, and Dave looked startled. The blast on the whistle had been so unexpected and authoritative, that they too had stopped fighting. The girls now hurried toward them.
“Who blew that whistle?” Burt asked.
The three girls burst into laughter, and Nancy admitted that she had. “It’s the first time I ever tried to play policeman, but I must