Oservations on solar radiation were made with a pair of maximum thermometers, one black and one bright bulbed, in vacuo, exposed horizontally on a post 4 feet high on the knoll southwest of the station. They were mounted side by side in a movable frame so that they could be brought into the house in stormy weather. Time = Washington Mean Time (correction for mean local time -5h 17m). Temperature were given in degress Fahrenheit, which has been converted to degress Celsius by Tc = (Tf - 32) * 0.555556.