declined."

CHAPTER III.

TEACHING A RASCAL A LESSON.

"Now hold on, young man, don't be so fast," said the stranger. "You do
not know me now, and I don't blame yer fer not wantin' anybody yer don't
know doing anything fer yer horse; but here's my card--Professor James
Colbath--and now I know you have heard of me. I am one of the greatest
veterinary surgeons in the country."

Frank ignored the card, and the man began to show signs of anger.

"This is no bluff!" he exclaimed. "It's on the level. I have nary doubt
but I can find out what's the matter with the critter in five minutes,
and if I don't give yer a square deal I don't want a cent for my
services, that's all."

He would have lifted one of Nemo's feet, but Frank cried:

"Drop that! I tell you I don't want you, and I won't have you! Get away
from this horse!"

The man growled and stiffened up.

"All right," he said, somewhat savagely. "I did think of trying to buy
the critter off yer, but you're too flip. If the animal stays lame,
don't blame me."

Although Frank had seemed to pay very little attention to the stranger,
he was inspecting him closely. He saw the man had pulled his hat down
over his eyes, and wore his coat collar turned up. He had a black beard
that concealed his features to a great extent.

Grody was also looking the stranger over closely. He fancied he detected
a familiar sound in the man's voice. The light in the stable was rather
dim, and that served to make the inspection of the boy and the hostler
rather unsatisfactory.

All at once, Grody started as if struck by a sudden idea. As soon as
possible, he whispered in Frank's ear:

"That mug is the same chap that were here this afternoon, sir."

"The same chap? What chap?"

"The one what gave his name as Diamond."

"No? You said that fellow had no beard."

"I don't believe this man's beard is all right."

Frank was aroused. He fancied that he saw a ray of light.

The fellow who had called himself Professor Colbath turned away. He had
heard the hostler whisper, and he caught Frank's question. Immediately
he showed a desire to get out.

Leaving the horse to Grody, Frank quickly placed himself before the
stranger, saying:

"Hold on a minute. I don't know but I'll talk with you a little."

"No, yer won't!" growled the man. "I'm done tryin' to talk with a fresh
youngster like you--I'm done with you."

"Well, I am not done with you!"

Frank's voice rang out sharp a