...iver. Major-General Foster, with the iron-clad Sangamon and the gunboats Commodore Barney, General Jessup, and Cohasset made an expedition up the James River. At a point seven miles from Fort Darling , near Dutch Gap, a torpedo was exploded under the bows of the Commodore Barney, by a lock-string connected with the shore. The explosion was terrific. It lifted the gunboat's bows full ten feet o...