Inverse drop calorimetry performed in a SETARAM HTC 1800 K was used to measure the values of relative enthalpy of the ternary eutectic melt in the system C3S2-CS-C(2)AS in the temperature interval 1653-1773 K with regard to the reference state of a mechanical mixture of gamma-C2S, CS, and C(2)AS crystals of corresponding composition at 298 K. The linear temperature dependence of specific relative enthalpy and the temperature-independent value of specific heat capacity of the eutectic melt (eut.melt) c(p)(eut.melt)/(J g(-1) K-1) = 1.760 +/- 0.089 were determined from measured data. The specific enthalpy of crystallisation of eutectic melt at 1583 K Delta(cryst)h(eut.melt; 1583 K) = (-324.6 +/- 14.4)J g(-1) was calculated using specific relative enthalpy of eutectic melt at 1583 K determined experimentally, enthalpies of formation of C3S2, gamma-C2S and CS at 298 K, and enthalpy increases on heating of C3S2, CS, and C(2)AS from 298 to 1583 K taken from literature. The material balance of the process was also used. The value of specific enthalpy of crystallisation of eutectic melt at 1583 K represents about 25% of the heat released on subsequent cooling of the separated crystals of C3S2, CS, and C(2)AS from 1583 to 298 K.