The crowd was being constantly reinforced as the day wore on. A number of gentlemen attacked one gang of the ruffians, and succeeded in capturing two of them. About five o’clock a large squad of rioters attacked a building on Twenty-ninth street, because it was alleged that “Horace Greeley lived there.” While engaged in the destruction of the house and its contents a detail of about fifty soldiers and thirty policemen appeared on the ground and marched through the street clearing it of all obstructions. A short time afterwards, in another portion of the street a gang of rioters raised a cry against a gentleman passing by “that he was a Tribune reporter,” and instantly he was set upon by the infuriated mob, who pursued, knocked him down, and beat and kicked him about the body, face and head in such a way as to leave him nearly dead. A gentleman present interfered and succeeded in saving the young man’s life. He was taken to his residence near, and it was found on examination that he had received no mortal wound. This same mob while in the vicinity set upon a man against whom they had conceived some fancied antipathy, and beat him to death. The riot was now increasing in all parts of the city notwithstanding the vigorous measures adopted for quelling it. An attack was made upon the residence of Mayor Opdyke by a comparatively small body of men and a party of boys, who threw stones and brickbats at the windows. Not more than half of the rioters, however, entered the building, their object evidently being plunder. About twenty gentlemen living in the neighborhood, having anticipated the attack, assembled at a given place, and, with such weapons as were at hand, rushed upon the crowd and drove them from the door. They then entered the Mayor’s house and speedily expelled the rioters. Meantime the mob was increasing and the cry was “Burn the building!” The front steps were then occupied by the small party of gentlemen whose determined looks the crowd did not seem to relish. Happily, a body of police appeared, and charging upon the rioters put them to flight. The policemen were relieved by a detachment of two hundred soldiers. One of the most atrocious and bloodthirsty acts of the second day’s riot was the murder of Colonel O’Brien, who had command of a portion of the military troops. The mob having been in great measure dispersed, a temporary quiet ensued toward evening, and Colonel O’Brien took advantage of this circumstance to return to his residence, and remove his family to a place of safety, fearing the violence of the rioters against them, for he had heard many threats to that effect. He alighted from his carriage in Thirty-fifth street, and had just entered his house when a part of the mob, who had apparently been watching for him, made their appearance, and pouncing upon him dragged him into the yard, where they beat and kicked him in the most brutal manner.