The given activity is dedicated to a permeability of a liquid in capillary tubes of different geometry, in particular to analysis of a permeability of soil. We attempt as a first approximation to evaluate as pore size, their form, influence quantity of a liquid, which one lingers over in the given pore etc. For definition of the characteristics of pores the model of "ideal soil" was used, which one represents chaotic packaging of spherical fragments. The calculations were conducted outgoing from a condition of minimum potential energy of a volume of a liquid in pores.

As a result of the conducted research for an estimation of water volume in an ideal capillary tube alongside with the formula of the Fisher, it is possible to use the formula obtained at the rate of a minimum of potential energy of a liquid.