Continuous Flow Calorimeter Callendar And Barnes:-For electric equivalent of heat of liquids. A glass tube, 360 mm long, containing manganin spiral heating element with screw terminal at each end, is connected to inlet and outlet cylindrical vessels,each having a tubule for thermometer. The inlet system has a long vertical vent tube to allow air bubbles in the incoming water to escape. Mounted on wooden base, but without constant level tank or thermometer.