Isoperibolic titration calorimetry has been used to determine tie-triangles (i.e., compositions of conjugate top, middle, and bottom phases) of the system C6H13(OC2H4)(2)OH/n-tetradecane/water at seven temperatures from 15 through 45 degrees C, The concentration of each component in each phase was approximately a linear function of temperature over this temperature range. The density of C6H13(OC2H4)(2)OH from 24 to 50 degrees C also is reported.