One of my ancestors, a James Dalton of Manchester, fought as a ship's boy (volunteer) on HMS Mars at Trafalgar. The next I find of him is in the Lancashire Lunatic Asylum in 1841, described as a 'patient; sailor'. Does anyone have any idea how to find out what he did in the interim period? Do ships muster rolls exist for all ships in the Napoleonic period? Is he likely to have joined the Merchant Navy once Mars was paid off? Thanks.