Data for liquid metals is reinterpreted in terms of a model in which the surface is solid in the direction normal to the surface but is disordered in directions parallel to the surface. Thermal motions previously termed capillary waves become vibrations along the normal axis and therefore lack viscous damping. The model, which applies to liquids with surface-induced layering, avoids problems that arise when such a surface is analyzed as a simple liquid, notably (i) negative dilatational viscosity, (ii) unexpectedly large surface tension, and (iii) the need to restrict surface waves to low k-values to ensure normal-mode excitations. (C) 2012 Elsevier B. V. All rights reserved.