Don't forget, there were also "spar torpedoes", which were bombs on the ends of poles and which were designed to be rammed into an enemy vessel. They were as dangerous to the user as to the target. Cushing used one against the CSS "Albemarle" and sank the ironclad, but the explosion swamped his steam launch. The Confederate submarine "Hunley" used one against the U.S.S. "Housatonic", again sinking the target, but the "Hunley" never made it home - until 2001, that is. What we generally think of as a "torpedo" did not come out until the Whitehead self-propelled torpedo in the 1870's.
The David class semi submersibles had spar topedoes too. The first one rammed the new Ironsides in Charleston Harbor and did some major damage to the ship. Only problem is the back wash from the explosion washed over the David putting out the fire in the engine stopping the David for a while til they got it lit again .
I'm looking at this thread (yeah, I know this is a bit late) and I'm thinking that I read somewhere the modern torpedo was originally refered to as a self propelled torpedo to seperate it from the stationary and spar torpedos.