Jerrycan
It's amazing how much clever engineering went into such a simple device.And how much it is forgotten today. I have a couple 5 gallon plastic gas containers. They are terrible in comparison. For example, instead of an air pipe to allow smooth pouring, there's a separate cap which has to be unscrewed, and then the cap is inevitably lost.Modern ones have this spring-loaded spout, which is supposed to prevent spillage. It inevitably causes spillage, because the spring is so strong you cannot regulate the flow, and the tank fills too fast and overflows. I hate spilling gas every time I load the lawnmower tank.