Variation in Evaporation in Limited Areas

During a study made at the Macbride Lakeside Laboratory in the summer of 1913 a series of observation stations were set up on the hill known as Twin Mounds, on the south shore of East Okoboji lake. This hill rises from the lake front to a height of about 100 feet and has a dense growth of timber on the protected face of its north slope. The top is bare of trees, as also is the entire south slope, which is exposed to the prevailing southwest winds of summer. Seven stations were arranged, located as follows: one on the summit of the hill, and three at equal distances down each of the two sides of the hill. At these stations there were made observations of the evaporation, using both pan and Pische evaporimeters; of the direction of the wind and its velocity, as measured by two standard types of anemometers; of the relative humidity of the air, as indicated by sling psychrometers; of the percentage of sky cloudiness, and of other factors that might influence the local flora