“Right in line with that big rock,” went on the scientist, who had very good eyes and could see a long distance.

“It’s only a tree stump,” spoke Bob.

“I didn’t know tree stumps could move,” went on Mr. Snodgrass, “for this one is certainly coming toward us. It’s not a bear after all,” he continued, now that the object was nearer. “It’s a bull! That’s what it is! It looks as if it meant to go for us!”

The boys could now see that the beast was one of the big, long-horned western cattle. It had evidently strayed from the herd, or had been made an outcast because of a bad temper and a perpetual desire to fight. The latter seemed more likely, for, as the auto proceeded, and the bull came on, lessening the distance between the two, a defiant bellow of rage sounded.

“I hope he don’t try to ram us,” spoke Jerry. “We don’t want any more collisions.”

“See if you can’t run away from him,” suggested Ned.

By this time the bull was about one hundred yards away. It was coming straight for the auto. Jerry opened the muffler and at the sound of the explosions the bull stopped short.

At this point the road ran in a sort of depression, with hills rising on either side. It was rather narrow, so there was no chance to turn to one side. Jerry had to bring the machine to a stop or else run the risk of hitting the bull. He thought the animal might run away if it saw the machine coming toward him, but there was nothing sure about this.

“Well, this is a regular hold-up,” said the professor. “I wonder whether the bull wants to collect toll?”

The animal seemed to be growing angrier and angrier every minute. It bellowed loudly, pawed the earth with its hoofs, and shook the lowered head, armed with sharp horns. Occasionally the keen points would tear up the ground.