A graphical recorder for a pan evaporimeter has been developed. Water from a reservoir is pumped at a steady rate to the pan in which an overflow device maintains constant level, the overflow water being returned to the reservoir by gravity flow. The change in level of the water in the reservoir represents the difference between evaporation from the pan and precipitation. The record is made on a vertical cylindrical chart, the recording pen having direct coupling to a float in the reservoir. Recording amplification is determined by the pan‐to‐reservoir area ratio. In the present model, amplification values of 2 and 5 can be selected by a cock that controls a tubular by‐pass between concentric reservoirs. (Key words: Evaporation; instruments.)