Heat transfer solely by molecular conduction in the metalimnion.

During the year August 29, 1965, through August 28, 1966, weekly samples of water were taken from Linsley Pond, North Branford, Connecticut, for the purpose of as complete a geochemical survey as possible. At the same time, temperature studies were made at half-meter intervals for the column, from the surface through 14 M, using a YSI thermistor reader and thermistor accurate to at least 0.050C. Oxygen determinations were made at similar levels from February 12, 1966, through August 29 of the same year. In 1937 Hutchinson' made a thorough study of thermal conditions in Linsley Pond and gave an analysis of the heating process during June, July, and August. The new data here considered, obtained between June 5 and August 21, 1966, are comparable to those obtained in 1937. Figure 1 shows the mean rate of change of temperature with respect to time plotted on semilog paper against depth for the 1966 period (dots) and for the 1937 sequence (triangles). Comparison of the two