I tend to think of our home grown British Seagull outboard engine as the pinnacle of Victorian engineering in the tradition of Watt and Stephenson, but it's clear there were many other innovators along the path to our modern outboard engines.
This example was seen in the 5th Wind boatyard in France, it seems like the type of straight shaft outboard which is seen in the far east (and some of the James Bond movies) only somewhat older and more modest. The whole device looks like it pivots on that vertical post and presumably the long shallow draft was good for the Loire river with is shallows and frequent sand bars.
The engine is pretty familiar if old design with what looks like a cast iron cylinder and a heavy external flywheel, clearly safety wasn't the first design consideration.
Down at the business end the skeg gives the twin bladed prop some directional stability even at low revs.