The apparatus consists of a precision-bore glass pipe held vertically in a large shroud. The shroud is open at the front and the inside surface is light coloured. This allows the students to see the flow clearly. Free-standing apparatus that gives a visual demonstration of laminar and turbulent flow. Water enters a constant head tank above the test tube and passes through a diffuser and stilling bed. This arrangement ensures a steady, uniform flow at entry to the test tube. It then passes through a specially shaped bell-mouth into the test tube. A thermometer measures the temperature in the constant head reservoir. At the bottom of the test pipe is a valve which controls the flow rate through the pipe, without disturbing the flow. A fixed overflow pipe in the reservoir connects to a suitable drain. They use it to inject a fine filament of dye into the top of the tube. The dye injector is a dye reservoir connected to a fine hypodermic tube.