A novel experimental scheme has been developed in order to measure the heat
capacity of mass selected clusters. It is based on controlled sticking of atoms
on clusters. This allows one to construct the caloric curve, thus determining
the melting temperature and the latent heat of fusion in the case of
first-order phase transitions. This method is model-free. It is transferable to
many systems since the energy is brought to clusters through sticking
collisions. As an example, it has been applied to Na\_90\^+ and Na\_140\^+. Our
results are in good agreement with previous measurements