The permeability and fluidisation can easily be demonstrated with this apparatus. These processes can be accompanied by simple domestic water (tape water) and suitable porous granular media. This permeability depends on physical characteristics of the liquid and geometric characteristics of the porous media, expressed by the Kozeny-Carman equation. Apparatus is consists of a metal framework, constant head tank and transparent test section for observation. Flow is indicated by a Rotameter. A 0.5 m water differential manometer and 0.5 m mercury manometer are included for pressure drop across the bed.