Wetting on a geometrically structured substrate

We have measured the growth of liquid films of Ar and Kr adsorbed on a geom etrically structured substrate obtained by machining on a lathe a thin Al d isk with a sharp cutting tool. Near liquid-vapor bulk coexistence, the film mass is found to diverge as a power law of the chemical potential differen ce from saturation with an exponent x=-1.93 +/-0.10, in very good agreement with recent scaling analysis results. (C) 2001 American Institute of Physi cs.