Then Δθ = θₙ − θ₀ + C = 211°.4 − 162°.9 + 1°.13 = 49°.63. The true end temperature = θₙ + C = 212°.53. The zero point of the thermometer = 24°.70, and the actual rise of temperature = 187°.83. The rise of temperature due to the proximity of the warming apparatus at the beginning was found by experiment to be equal to 0°.1 of the division of the scale. On comparing the thermometer used with a standard centigrade scale it was found that one division of the calorimetric thermometer was equal to 0°.0858. Converting these numbers into expressions of the centigrade scale we have the following summary: The true rise of temperature, Δθ = 4°.25 The true end temperature, θₙ + C = 16°.10 The temperature of the steam, as determined by the height of the barometer, was equal to 97°.70 From these data the specific heat is calculated according to the following formula: Σ = 1/20.769 × ((100 × 4.25)/(97.70 − 16.10) − 0.8692) = 0.2089. From this formula the following rule for calculating specific heat is deduced: Multiply the water value of the calorimetric system by the true rise in temperature in degrees Celsius and divide the product by the difference between the temperature of boiling water under the conditions of the experiment and the true end temperature. From the quotient subtract the water value of the envelopes holding the soil sample. Divide the remainder by the weight of soil taken. =111. Variations in Specific Heat.=—Different soils deport themselves very differently in respect of specific heat. In a large number of soils examined by Pfaundler, the specific heats were found to vary from 0.19 to 0.51. The highest specific heat was observed in the case of a peaty soil. Next to peaty soils came those soils which were highest in humus, and in general it was found that the specific heat varied directly with the humus content. SOIL THERMOMETRY. =112. General Principles.=—The measurement of the temperature of the soil at stated depths is often of use in analytical processes connected with agricultural chemistry and physics. The general principles on which the process rests, depend on bringing the bulb of the thermometer into as intimate contact as possible with the particles of soil at the depth required, disturbing as little as possible the normal state of the soil particles. In the thermometer chiefly used for this purpose in this country, the stem is strong and carries the degrees figured on the glass. The whole is inclosed in a wooden case which is cut away to expose the face of the scale. The scale is about eleven inches long. The part which enters the soil is of varying lengths, according to the depth at which the temperature is desired. =113. Method of Procedure.=—An excellent method of determining soil temperatures and of recording results is well illustrated by Frear.[76]