Both men drew back so violently that they toppled over backwards.

’Mid the crashing of dishes and the sound of breaking wood, the dinner table shot up into the air, while the pony ploughed the ground with its nose.

Ned Rector struck the ground some distance farther on; he slid on his face for several feet skinning his nose, and filling mouth, eyes and nose with dirt.

Then dishes and pieces of table began to rain down on them in a perfect shower.  A can of condensed milk emptied itself on the head of Professor Zepplin, while a hot biscuit lodged inside the collar of Santa Claus’s shirt.

“Wow!  Oh, wow!” howled the fat boy, falling off his pony in the excess of his merriment and rolling on the ground.

CHAPTER XVII

 In the home of the cave dwellers

Ned Rector sat up just in time to meet the wreck of the descending table.  Down he went again with Stacy’s howls ringing in his ears.

A firm hand jerked Rector free of the debris as Kris Kringle laughing heartily hauled Ned to his feet.  At the same moment Professor Zepplin had laid more violent hands on the fat boy, whom he shook until Stacy’s howls lost much of their mirth.  About this time Tad and Walter rode in, having hurried along upon hearing the disturbance in camp.

“Stacy Brown, are you responsible for this?” demanded the Professor sternly.

“I’m more to blame than he is,” interposed Ned.

“No, I—­ I had an idea,” chuckled Stacy, threatening to break out into another howl of mirth.

“Next time you have one, then, you will be good enough to let me know.  We will tie you up until the impulse to make trouble has passed.”

Tad and Walter could not resist a shout of laughter.  Kris Kringle was not slow to follow the example set by them, and all at once Professor Zepplin forgot his dignity, sitting right down amid the wreck and laughing immoderately.

Ned washed his face, and when, upon facing them, he exhibited a peeled nose and a black eye, the merriment was renewed again.

Supper was a success, in spite of the fact that many of their dishes were utterly ruined, as well as some of the provisions.  But the lads gathered up the pieces and made the best of a bad job.  Fortunately they carried another folding table that they had had made for their trip, and this was soon spread and a fresh meal prepared.

“Well, have you two been getting into difficulties also?” questioned the Professor, after they sat down to supper.

“No; we’ve been exploring, Walter and I,” answered Tad.

“Exploring?”

“Yes.  We discovered something that I should like to know more about.”

“What is that?” asked Kris Kringle, looking up interestedly.

“We were over yonder, close to the mountains, which are straight up and down, and half way to the top, we saw three or four queerly-shaped rocks that looked like houses or huts.  Did you ever see them, Mr. Kringle?”