Calling his comrade to his help, McWatters carefully noted each passenger as he was leaving the steamer. As Velge came up, Mac recognized and arrested him. He was thunderstruck at the occurrence, and protested his innocence. The officers conveyed him to the central office, and laid the case before the superintendent. The prisoner showed that he was an old resident of this city, though only twenty years old. Several of his relatives were at headquarters yesterday pleading his innocence. The clergyman who had caused his arrest made his statement to the superintendent, who finally decided to retain the young man in custody till he could be brought before a magistrate. There was certainly a striking resemblance between the portrait and the countenance of the prisoner. If the suspicions now entertained should prove to be well founded, this is another instance of the perpetration of crime followed by its speedy detection. ------------------------------------------------------------------------ EXTENSIVE COUNTERFEITING. SEIZURE OF FIFTY THOUSAND DOLLARS IN SPURIOUS POSTAL CURRENCY--ARREST OF THE COUNTERFEITER--HIS CONFESSION. In the New York Times of November 20, 1865, we find an article with the above caption, and which we copy as below. The arrest therein spoken of created much sensation at the time, as well it might. Officer McWatters acted in the matter, not only as an ordinary member of the police force, but in the capacity of a detective, and won great credit by his sagacity. "An important arrest was effected in Brooklyn last Tuesday, the particulars of which have been suppressed up to the present time. The Treasury Department at Washington have long been aware that the business of counterfeiting greenbacks and postal currency has been carried on to an alarming extent at different points throughout the country, but their endeavors to arrest the guilty parties have, with a few exceptions, been attended with failure, or only partial success. One exceedingly skilful engraver of bogus postal currency has been especially marked as the most dangerous operator, inasmuch as his execution was so perfect as frequently to deceive even the Government officials; and the boldness of the counterfeiter was almost as great as his skill. The man in question is an English engraver, by the name of Charles J. Roberts. The best Government detectives have been on his track for six months, without succeeding in finding him, until last Tuesday, when his arrest was effected in Brooklyn, by Messrs. R. R. Lowell and A. J. Otto, detectives in the service of the Treasury Department, with the assistance of Officer McWatters, of the Twenty-Sixth Metropolitan Precinct.