This experimental unit consists of a precision-bore glass pipe held vertically. The constant head tank is made of transparent acrylic. This allows the students to see the flow clearly. Water enters a constant head tank (reservoir) above the test tube and passes through a stilling bed. It then passes through a specially shaped bell-mouth into the test tube. This arrangement ensures a steady, uniform flow at entry to the test tube. A thermometer measures the temperature in the constant head reservoir. A fixed overflow pipe in the reservoir connects to a suitable drain. At the bottom of the test pipe is a valve which controls the flow rate through the pipe, without disturbing the flow. Students collect a known quantity of water in a measured time to find the flow rate. Included is a measuring cylinder. To see the pattern of flow in the pipe, students use a dye injector (included). They use it to inject a fine filament of dye into the top of the tube. The base of the apparatus has adjustable feet for levelling prior to use with the included levelling device.