“Will some one please muzzle the fat boy?” begged Ned.

“You can go out and hide in the bushes while I’m telling the story,” returned Chunky.  “This is a nice ladylike story.  It’s about a fellow—–­a clerk who was out with a party of surveyors, running a line across the desert.  The water holes had gone dry and they were choking for water when the clerk saved them and—–­”

“Ring the bell!  Ring the bell!” shouted Ned Rector.

“Yes, you have told us that story twice to my positive knowledge,” spoke up the professor.

“Of course he has,” agreed Walter.  “The clerk found water for them and they were saved,” added Tad, laughing immoderately.

“Did he?” demanded Chunky eyeing them soulfully.

“Yes, of course he did.  You ought to remember the story.  You have told it often enough.”

“How did he save them?”

“He had a fountain pen, of course, silly!  Have you forgotten your own story?” scoffed Tad.

“He didn’t have anything of the sort.  This was another clerk.  This one had a watch.”

Stacy glanced around expectantly.  Not a face was smiling.  All were as solemn as owls.

“He had a watch,” nodded Rector.

“He had a watch,” added Tad.

“I wonder if the watch was running?” piped Walter.

“No, it was stagnant,” retorted Stacy.

“Young gentlemen, for the sake of bringing a long-winded discussion to a close, I will offer myself as—–­as what you call a ‘mark.’  What had the watch to do with their thirst?” asked the professor gazing sternly at Stacy.

The boys shouted.

“Come down with the answer, Chunky.”

“The watch had a spring in it,” answered the fat boy solemnly.

“I think it’s going to snow,” observed Tad consulting the skies reflectively.

“Yes, the air is very chill,” returned Ned Rector solemnly.  “Shouldn’t be surprised if some one perished in this outfit.”

CHAPTER XV

MAKING A STARTLING DISCOVERY

Stacy Brown looked from one to the other of his companions in disgust.

“Ho, ho! ho, ho!” he exploded.  “Hard luck when a fellow’s company is so thick that he has to laugh at his own jokes.  Ho, ho, ho!  Ha, ha, ha!  It is to smile, but nobody smiles.  You make me tired.”

“As I have already observed, I think it is going to rain,” said Tad.

“Must be getting warmer, then.  A minute ago you said it was going to snow.  It’s my private opinion that you don’t know what you think.  Ned doesn’t know any more.  The professor is the only one in the outfit who has a sense of humor. He knows when it’s time to laugh.  Ha, ha!”

Professor Zepplin was smiling broadly.  Stacy’s joke was just dawning upon the professor.  But Tad’s mind at that juncture was in another direction.  The lad had raised his head in a listening attitude, his glance fixed keenly on the other side of the camp ground.