The deceased was a well-educated and genteel young man, about twenty years of age, and we believe a relation of Lord Cochrane. A coroner’s inquest sat upon the body, the jury delivered their verdict, “wilful murder,” against Major Lockyer, and Messrs. Redesdale and Hand, and the coroner issued his warrant for their apprehension. Mr. Hand was apprehended (by Allen, the Newport constable) at Portsmouth, on Thursday; the others are at large. Major Lockyer and Mr. Hand were tried at Winchester Assizes, on the 7th of March, 1818; and the jury returning a verdict of manslaughter, they were sentenced to three months’ imprisonment. BETWEEN MR. THEODORE O’CALLAGHAN AND LIEUTENANT BAILEY. Bow Street, January 13, 1818. Yesterday morning, between eight and nine o’clock, Mr. Theodore O’Callaghan, and Lieutenant Bailey of the 58th regiment, met in a field near Chalk Farm, to fight a duel, accompanied by Mr. Charles Newbolt, and Mr. Thomas Joseph Phealan, as seconds. Lieutenant Bailey received a wound in his right side, which proved fatal, as he languished about two hours, and then expired. Mr. O’Callaghan and the two seconds were afterwards taken into custody, and brought to this office, when they underwent an examination before Mr. Conant, the sitting magistrate, and the following particulars transpired:— Thomas Hunt, a constable at Hampstead, stated—That he was sent for to Mr. Adams’s house, near Chalk Farm, in Ingram’s Lane, near the Load of Hay, where he took the prisoners into custody, in consequence of a gentleman having been killed in a duel.