The thermometers are set in niches cut in a trench, the earth being afterwards carefully tamped about the bulbs to secure a good contact, the trench being filled at the same time. The surface of the soil is freed from vegetation and kept in good tilth. The depths at which observations are made are at the surface and one, three, six, twelve, and twenty-four inches. The soil tested was moderately dark and loamy to a depth of seven inches and below that a stiff clay. Solid rock existed at from five to seven feet below the surface. Readings were made three times a day. =114. Method of Stating Results.=—The individual readings of the thermometers should be entered at the time they are made. At the end of each month the mean of the readings should be determined, together with the maxima and minima, and a comparison made between the mean readings of the temperature of the air and maxima and minima. As a sample of the method of stating these mean results the data are given for the month of May, 1891, for the atmosphere, surface, and for the depths mentioned above: MAY. T° Fahrenheit. ATMOSPHERE. Monthly mean 57.1 Maximum 85.0 Minimum 31.0 Mean daily range 22.5 Greatest daily range 32.0 Least daily range 8.0 SURFACE. Monthly mean 56.7 _Extremes._ Maximum (10th of month) 77.0 Minimum (5th) 36.0 Mean maximum 65.2 Mean minimum 49.9 _Range._ Monthly 41.0 Mean daily 14.9 Greatest daily (19th) 25.0 Least daily (21st) 4.0 ONE INCH. Monthly mean 56.8 _Extremes._ Maximum (10th) 74.5 Minimum (5th) 36.5 Mean maximum 62.9 Mean minimum 49.5 _Range._ Monthly 38.0 Mean daily 11.9 Greatest daily (10 and 19) 20.0 Least daily (23rd) 1.0 THREE INCHES. Monthly mean 56.7 _Extremes._ Maximum (31st) 71.0 Minimum (6th) 40.0