mules were not and over this difference of inclination they had many
disagreements.

Once Ned lost his temper with the beast of burden that he had in tow,
and used his crop rather too freely to suit the long-eared animal.
The latter kicked until he kicked the pack from his back.

Amid the shouts of laughter of his companions, his face red and
perspiring, Ned was obliged to gather up the pack in sections and
strap it in place again, which he did after much endeavor. Thereafter
he kept his temper.

"I've heard it said that a mule wouldn't kick after twelve o'clock,"
said Chunky. "Guess it wasn't true."

"Perhaps it is after twelve o'clock at night that was meant,"
suggested Tad.

"Mules are asleep then, aren't they?"

"Supposed to be, I guess."

"Then that's it," answered the fat boy somewhat enigmatically.

They failed to make any great distance that day. How far they had
advanced they did not know. Shortly before sundown they called a halt
at Professor Zepplin's suggestion.

The mules went to sleep while the boys were unloading them. Ned
confessed that he was nearly fagged. Tad, on the other hand, declared