"Where's Stacy?" was the Professor's first question.

"He's gone by the air line," answered Walter.

While all this had been taking place Chunky had continued in his mad
flight for a short distance. He had a long hold on the rope by which
the mustang was hauling him. The wary beast, espying a tree whose
limbs hung low, changed his course and darted under the lowest of
the limbs. Its intention was plain to those who knew the habits of
these gentle beasts. The mustang intended to "wipe" the Pony Rider
boy free of the line.

Just before reaching the low-hanging limb the pinto darted to one
side, then to the other after an almost imperceptible halt. The
result was the rope was drawn under the low limb. A quick leap on
the part of the mustang, that exhibited almost human intelligence by
this manoeuvre, caused Chunky to do a picturesque flop over the limb,
falling flat on his back on the other side. This brought the mustang
to a quick stop, for the rope had taken a firm hitch around the limb.

The sudden jolt and stoppage of his progress threw the mustang on his
nose, where he poised for a few seconds, then he too toppled over on
his back.

The owner of the herd was screaming with, merriment, Jim Nance was
slapping his sides as he ran, while the Professor was making for the
fat boy with long strides.

Tad reached Stacy first. The fat boy lay blinking, looking up at him.