On the last evening spent in Melbourne the boys decided to take a farewell walk about the city, not knowing when it would again be their fortune to see it. Neither Fletcher nor their new Yankee acquaintance was at hand, and they started by themselves. They did not confine themselves to the more frequented streets, but followed wherever fancy led.

They had no thought of an adventure, but one awaited them.

As they were turning the corner of a narrow street, their attention was suddenly excited by a sharp cry of blended surprise and fright.

"What is it, Jack?" asked Harry, grasping his companion by the arm.

He did not need to await a reply, for by the indistinct light he saw two men struggling a few rods further on. One appeared to be an old man, with white hair, the other was a man of middle age. Clearly it was a case of attempted robbery.

"Run, Jack, run!" said Harry, in excitement. "Let us help the old man!"

"I'm with you," answered the young sailor briefly.

Harry had in his hand a heavy cane—his only weapon—but he did not stop to consider the personal risk he was running. As he drew near, the old man, whose feeble strength was quite unequal to a conflict with a man so much younger, swayed and fell backward. His assailant bent over him, and despite his feeble resistance began to search his pockets, at the same time indulging in savage threats. The old man gave himself up for lost, but help was nearer than he anticipated.

So occupied was the villain with his disgraceful work that he did not hear the approaching footsteps.

His first intimation of them came in a sounding blow over his shoulders, given by Harry's stick, which was laid on with a good will.

He jumped to his feet with an oath, and darted a rapid glance at his two assailants. Then, much to the surprise of Harry, he turned and ran rapidly away. It was a piece of great good luck, Harry thought, for he was not at all sure that he and Jack combined would have been a match for the highwayman.

"Are you hurt, sir?" asked Harry, bending over the old man.

"Not seriously," was the reply. "Will you kindly help me up?"

With Jack's help Harry got the old man on his feet. He was a tall man, of splendid aspect, over sixty years of age. He looked like a gentleman of wealth and position.

"You have had a narrow escape, sir," said our hero.

"Yes, indeed," answered the old man, "thanks to your brave interference. It surprises me that my brutal assailant should have run away from two boys."

"I am surprised also, sir. I feared we should have a hard fight. I suppose his object was robbery."

"Yes, he must have heard in some way that I had a large sum of money about me. Thanks to you, it is safe."

"I am very glad, sir."

"Do you mind accompanying me to my house? This attack has made me timid."

"With pleasure, sir."

The old gentleman lived perhaps a quarter of a mile distant in a handsome house. He pressed the boys to enter, and they did so. He questioned them as to their plans, and then selecting two bank-notes of large denomination, urged the boys to accept them as a recognition of the help they had given him at a critical moment. The boys, however, declined positively to accept any compensation, but expressed their satisfaction at having been of service.

"At least," said the old gentleman, "you must promise to call on me when you return from the mines. There is my card."

"That we will do with pleasure, sir," answered Harry.

He looked at the card, and read the name of Henry A. Woolson.

"Harry," said Jack, as they resumed their walk, "do you know that robber had a look like Fletcher?"

"So I thought, Jack, but I had only a glimpse, and could not be sure. I wish he were not to be in our party."

"We must be on our guard; I don't fancy him much."

When the boys saw Fletcher in the morning he appeared as usual, and they were disposed to think they were mistaken. Yet the lurking suspicion occurred to them from time to time, and made them feel uneasy.

The next day they set out on their journey, accompanied by Dick Fletcher and Obed Stackpole.