A heated towel was attached to one side of the box to heat the surface up. Then a drop of ink was dripped in the middle of water surface, the ink subsequently formed a circle following the current.
A heated metal was put at the bottom of the plexi box, then a drop of ink was dripped into water in the middle. Firstly, the ink went rapidly towards the metal, then it went upward on the way it came down. some ink flowed towards the edges and then started to go downward.