'm going to put one of Sam's artificial arms in the sleeve and
find somebody to shake hands with me. He'll shake so hard that I'm half
afraid my arm will come off."

"That's all right," laughed his companions as they assisted George to
carry out his plan.

When the motor-boat stopped at the dock the artificial arm had been
placed in the coat sleeve and George was assisted to the dock.

There George discovered one of the men who had helped in repairing the
Black Growler.

"Hello!" called the mechanic, discovering the boys and at once
approaching.

"Hello, to you!" called back George. "It's been a long time since I
have seen you. I shan't forget you for I have three or four good
reasons."

"I hope you won't," laughed the mechanic, "but I should like to know
what your reasons are."

"One reason," said George seriously, "was that you never shook hands
with me in the morning when you came to work."

"I didn't know you wanted me to," said the man. "I'll make up for lost
time now." As he spoke he grasped the hand which extended from George's
right sleeve and as George at that same moment turned quickly away, the
astonished handshaker stood holding in his grasp an arm which had
apparently come from the sleeve of the boy.

"That's right," said George soberly, pretending to be much grieved.
"That's right. First you don't shake hands and then you shake hands so
hard that you take my arm right off."

The sight had quickly drawn many of the people who were loitering about
the dock and for a moment they were startled to see what had been
apparently a serious accident.

"It's nothing," said George, turning to the assembly. "This man shook
hands with me and the first thing I know he had shaken my arm off. He's
welcome to it, however, and I hope it will do him some good."

The crowd was laughing noisily by this time and when George turned back
to resume his place on board the motor-boat, the mechanic was the
center of an observing throng which was inspecting the arm that he
still was holding.

Upon the return of the boys to the island, they discovered that Fred's
grandfather was seated upon the piazza conversing with a man whose form
impressed the Go Ahead boys as being familiar.

When they drew near the house John exclaimed in a low voice, "That's
our friend that we saw on the canal-boat."

His startled companions again glanced hastily at the man and Grant
said, "You're right for once in your life, String. That's ju