of water flow under different flow velocities using a small stream of dyed water introduced into the centre of clear water flow in a larger pipe.

The larger pipe was made of glass so the behaviour of the layer of the dyed stream could be observed. At the end of this pipe, there was a flow control valve used to vary the water velocity inside the tube. When the velocity was low, the dyed layer remained distinct throughout the entire length of the large tube. When the velocity was increased, the layer broke up at a given point and diffused