Before they reached the scene of the professor’s trouble, the learned gentleman had slipped wrathfully from the saddle to the ground and had planted himself in front of his refractory steed. Clinging to the bridle reins with one hand, the “prof” shook a finger in the mule’s face and commenced telling the brute what he thought of him.

“You belong to the stone age, you obnoxious quadruped,” he cried, “when the genus homo ruled the rest of creation with clubs and granite hammers! Your unmannerly attempts to relieve yourself of my weight, should bring upon you punishment of a most severe nature. If I were possessed of any instrument at all adequate, I should use it savagely in an attempt to subjugate you. As it is. I can merely pit my strength against your own, and pull. Will you come, you vicious, long-eared peace disturber? Will you?”

Hanging to the reins with both hands, the professor lay back on the bridle with all his strength. For a moment, Uncle Sam resisted; then, urged by some mulish, mischievous instinct, the brute allowed himself to relax abruptly and to lurch forward. As a result, the professor went backward, almost heels over head.

The reins were suddenly released. Freedom, perhaps, was what Uncle Sam had desired and had been working for. The instant he found himself free, he whirled around on his hind feet and would have cleared out in the direction of Ophir had Frank not deftly seized the flying reins.

The professor got up dazedly. Rubbing the small of his back, he passed his eyes over those who had just arrived upon the scene of his trouble with the mule. Then, recognizing those who had suddenly grouped around him, his face brightened.

“Ah, Merriwell!” he murmured; “and Clancy!”

“And Mr. Burke, from the mine,” added Clancy, smothering his enjoyment as he picked up the professor’s hat. “I guess you know Mr. Burke?”

“I believe we have met,” was the reply. “I was in a hurry to get from Ophir to the clubhouse, and so I borrowed Pophagan’s mule. That was a mistake,” he added ruefully, taking his hat from Clancy and carefully settling it on his head, “a very great mistake. If any one is in a hurry to transport himself from one place to another, about the worst thing he can do is to take Uncle Sam. A most perverse brute, young gentlemen! I assure you that I have spent nearly an hour on the road from Ophir to the clubhouse.”

“What was your hurry, professor?” inquired Merry, hiding his smile by turning toward Uncle Sam.

“News of most tremendous importance reached Ophir. I wanted to convey it to Mr. Bradlaugh. I was informed that he is playing golf on the club links, so I took Uncle Sam and started for the links.”