How long Mr. Lang might have remained in that position is not for us to determine.  But it would have been much longer, had not a loud rap at the outer door awakened him from his drowsy condition.

He started at the sound, and, taking in his hand a dim-burning candle, proceeded to answer the call.  Opening the door, a man closely enveloped in a large cloak and seal-skin cap, the last of which hung slouchingly about his head and face, inquired, in a gruff, ill-mannered voice, whether a person unfavorably known to the police as “Bold Bill” had been there.  Harry trembled, knowing his interrogator to be one of the city watch; yet he endeavored to conceal his fears and embarrassment by a forced smile, and remarked: 

“That is indeed a strange name, and one of which I have never before heard.  Tell me what he has been about.”

“Why do you think he has been about anything, or why think you I am acquainted with his actions?” inquired the stranger, in a stern voice, as though the supreme majesty of the law represented by him was not to be spoken lightly of.  His scrutinizing features relaxed not in the least, but he looked our hero steadfastly in the face.

“By the appearance of your dress I judge you to be a watchman, and as such I suppose you to be in search of that odd-named person on account of his being suspected of having broken the law.”

“You are right,” answered the officer.  “I am a watchman!  The authority invested in me is great.  I trust I duly appreciate it.  I guard your dwelling when you are slumbering, unconscious of what takes place around you.”

“You are very kind,” remarked Harry, suddenly interrupting him, and speaking rather ironically than otherwise.

The watchman continued:  “Life is to me nothing unless I can employ it in doing good.  Do you understand me?”

“Perfectly.”

“Will you walk in?” inquired Mr. Lang, as a sudden gust of wind nearly extinguished his light.

“No, I thank you; that would be of no service to my fellow-men; and, as I am in search of the man who committed the robbery, ten minutes ago, upon Mr. Solomon Cash, the broker, I must-”

“Robbery!” exclaimed Harry, appearing perfectly astonished at the thought.  “O, the degeneracy of the nineteenth century,—­the sinfulness of the age!”

“Amen!” responded the officer; and, pulling his large, loose cloak more closely about him, he made a motion to continue on in the service of his fellow-men.

“But wait, my good man,” said Harry.  “Am I to suppose, from what you said, that ‘Bold Bill’ is the perpetrator of this base crime?”

“Precisely so,” was the laconic reply; and the man moved on in execution of his benevolent designs.

“He should be brought to justice,” said Harry, as he turned to enter.  No sooner, however, had he closed the door, than he burst forth in a loud laugh.  This was soon changed to seriousness, for he became confident that his friend Bill was in danger.  To shield him, if guilty, from detection, and protect him, if innocent, was now his great object.  But where should he find him?  That was a problem he could not solve.  The boy was sleeping soundly; he must awaken him, he must go out in search of his friend.