Cooling classical particles with a microcanonical Szilard engine

We discuss the possibility of extraction of energy from a single heat bath in a cyclic process, under some special initial conditions. We give an explicit example in which a system initially prepared in a microcanonical ensemble, is able to perform such operation. The example is similar to the Szilard engine, but the microcanonical initial condition allows us to design a protocol where measurement is not necessary. We also discuss the limitations and possible extensions of this microcanonical Szilard engine.