My information on Harby is that he was not in command of the Neptune during the Battle of Galveston but he was in command of the two howitzers that were mounted on the Neptune. That is probably the source of the confusion about the scope of his command. He was apparently an expert in loading and firing large naval guns because of his experience on ships before the war. It is not surprising that he found his way down to Hobby's unit. That unit was required to occupy and man the guns in several coastal fortifications (many of them seized naval guns) and Harby's skills would have come in very useful.