A black box that has two holes, one small and one large. There is a tube at the bottom that drips once every time it is filled with water. After at least 470 ml of water it poured out water. A bucket that is under the tube is being filled when it pours. At least one minute after the it starts it stops.
It might have to do with the shape of the box. The water might be building up and when it overflows it might go over an edge and hit a lever that might open a trap door. It also might have to do with the water. It also might have to do with the tube. Maybe it is just curved upward to point to the top so it can capture water when it fills up.
Inside the box is a tube that curves like a fish that was sketched.
