Does the vertical tube in front of the tapered nozzle stick down into the can almost to the bottom? If it does, I'm betting on some kind of blow torch.
Fill the can with a flammable liquid, and put a cork in the hole. Then blow a stream of pressurized air into the tapered nozzle blowing across the top of the vertical tube opening. That will create a Venturi effect and suck up the flammable liquid atomizing it into a fine spray. Light it up and VOILA', blowtorch.
I'm thinking colonial or even pre-colonial. The air supply would come from a bellows.