Abstract: Weeds grow on the ballast of railway tracks, on sports fields, such as plastic running tracks, in parking lots and on cemetery paths. A machine is disclosed for eliminating them more economically. The weeds are sprayed with boiling water and steam at temperatures from 90.degree. and 140.degree. . A travelling device is used for that purpose having a water container, a heater device and spraying nozzles. When heated, the plant protein coagulates, and chlorophyll is totally or partially destroyed, causing the weeds to wither. The boiling water and steam can also be used to eliminate graffiti, oil traces and chewing gum from surfaces of all types, and thus to clean said surfaces.