Design improvements in an adiabatic calorimeter are described. The changes make it possible to load or unload the calorimeter in half an hour. A new regulation system is discussed and changes in the data collection and the data calculation programs are given. The molar heat capacity of cholesterol has been measured between 5 and 425 K. The derived thermodynamic properties are calculated. The solid-solid transition was found at 306.7 K, with an enthalpy of transition of 3886 J mol(-1). The melting temperature was found to be 422.3 K, the enthalpy of fusion being 28.4 kJ mol(-1).