All the steamers on the blockade except the Bellevite and the one in the west had been sent away on other duty, for it was believed that the former would be enough to overhaul anything that was likely to come out of Mobile Bay at this stage of the war. Sure of the steamer of which he was the executive officer, Christy directed his glass towards the one on the other side of the channel. She had received no notice of the approach of a powerful blockade-runner, and she had not a full head of steam when she discovered the Tallahatchie. Besides, she was one of the slowest vessels in the service.