Ganong's Potometer with Glass Stopcock and Wooden Base

The Ganong potometer is used to demonstrate transpiration rates and water absorption by a cut shoot under various external conditions. A plant shoot is sealed into a stopper at the end tube, and the entire apparatus is filled with water. The open end of the graduated capillary tube, marked in millimeters with a 1 mm bore diameter, dips into a beaker of water so that an air bubble can be tracked as the shoot takes up moisture. Adjusting the glass stopcock admits water from the reservoir, allowing the bubble position to be reset between readings. The instrument is mounted on a wooden base by clips, with the base measuring approximately 12.25 inches wide and the reservoir standing about 6.5 inches high. The reservoir diameter is approximately 0.75 inches. An instruction manual is included. The assembled unit weighs roughly 0.9 lbs.