in dread of what might happen, the rope tightened with a
jerk, and then threatened to break, for there was no yielding on the
part of the kegs after they had followed for a few yards, the sound
announcing that they had caught and become wedged amongst the stones.

In the midst of a painful silence Griggs said in rather an altered
tone--

"Well, it's of no use to make bones about it. I shall have to go and
give 'em a clearing shove or two."

"You'll do no such mad thing," cried the doctor angrily. "If the
rattlesnakes will face the darkness they must be swarming out of their
holes after this disturbance. Here, start afresh, Chris. Take the
mule's rein and lead him on steadily a little more to the right."

This was done, but the kegs did not move.

"Try to the left now, my boy."

Chris led the animal in the required direction, but the kegs remained
fast.

"You'll break the rope," said Griggs.

"Then we must make fast another," replied the doctor. "We must go
farther off now, and pull at right angles."

"You'll only get the rope cut by some of the upright stones," said
Griggs bitterly. "It's of no use, doctor. I must go back and--"

_Bump_!

At that moment, before the American had finished his sentence, there was
a quick movement, the tubs had yielded to the steady strain kept up by
the mule, and for the next few minutes they came on, gliding easily over
the sand, bumping and hopping over stones, against some of which they
collided in a way that threatened to knock off hoops or drive in staves,
but they kept on coming till the mule reached the first of its
companions, when the doctor called a halt.

"Now then," he said, "lanthorn here!"

"What are you going to do, father?" cried Chris anxiously.

"Pass the light along the rope till I reach the tubs, to see if there
are any snakes twisted about the chain."

"Nay, that's my job, sir," cried Griggs eagerly.

"We'll go together," said the doctor. "Every one else stand back."

The next minute Chris and Ned stood anxiously watching the light of the
lanthorn, which was made to run along the rope and the ground till it
played only upon the two kegs, which looked dull and indistinct by the
shadowy figures which could be dimly-seen.

"Look out, sir; there's one!" shouted Griggs out of the gloom, and the
lanthorn seemed to make a sudden jump.

So did Chris's heart at the thought of the danger to which his father
might be exposed.

The next moment th