“I’m sure they have the map,” the professor said.  “But I believe your plan is a good one, Tom.”

“Just what do you propose doing?” asked Ned.

“Fooling ’em!” exclaimed Tom quickly.  “We’ll dig in some place remote from the spot where the mountain casts its shadow.  They will think, if they haven’t the map, that we are proceeding by it, and they’ll dig, too.  When they find nothing, as will also happen to us, they may go away.

“If, on the other hand, they have the map, and see us digging at a spot not indicated on it, they will be puzzled, knowing we must have some idea of where the buried city lies.  They will think the map is at fault, perhaps, and not make use of it.  Then we can get it back.”

“Bless my hatband!” cried Mr. Damon. 
“I believe you’re right, Tom. 
We’ll dig in the wrong place to fool ’em.”

And this was done.  Search for the precious map was given up for the time being, and the professor and his friends set the natives to work digging shafts in the ground, as though sinking them down to the level of the buried city.

But though this false work was prosecuted with vigor for several days, there was a feeling of despair among the Bumper party over the loss of the map.

“If we could only get it back!” exclaimed the professor, again and again.

Meanwhile the Beecher party seemed inactive.  True, some members of it did come over to look on from a respectful distance at what the diggers were doing.  Some of the rival helpers, under the direction of the head of the expedition, also began sinking shafts.  But they were not in the locality remembered by Professor Bumper as being correct.

“I can’t imagine what they’re up to,” he said.  “If they have my map they would act differently, I should think.”

“Whatever they’re up to,” answered Tom, “the time has come when we can dig at the place where we can hope for results.”  And the following day shafts were started in the shadow of the mountain.

Until some evidence should have been obtained by digging, as to the location beneath the surface of a buried city, there was nothing for the travelers to do but wait.  Turns were taken in directing the efforts of the diggers, and an occasional inspection was made of the shafts.

“What do you expect to find first?” asked Tom of Professor Bumper one day, when the latter was at the top of a shaft waiting for a bucket load of dirt to be hoisted up.

“Potsherds and artifacts,” was the answer.

“What sort of bugs are they?” asked Ned with a laugh.  He and Tom were about to go hunting with their electric rifles.

“Artifacts are things made by the Indians—­or whatever members of the race who built the ancient cities were called—­such as household articles, vases, ornaments, tools and so on.  Anything made by artificial means is called an artifact.”

“And potsherds are things with those Chinese laundry ticket scratches on them,” added Tom.