Vertical pressure, σ, of a column of dry sand in an open cylindrical glass pipe, acting on the bottm is measured. It increases almost linearly with height. But increasing the height of the column in the same pipe, vertical pressure upon the bottom increases asymptotically and attains a certain final value, σf, which cahnges with a cross sectional arer, A, of the pipe. The relation of them can be formulated experimentally as follows, σf=1.15Aº·⁵².
Considering frictional force of sand acting on the sides of the glass pipe, the theoretically calculated formula is σf=1.22Aº·⁵⁰ .
When the dried sand is soaked with water, the relation of them becomes more complicated. The relation of σf and percentage of moisture content is investigated. In the case of a pipe with larger diameter (above 5.5-6 cm), σf takes a minimum value between 8 and 9% of moisture content. In a smaller pipe (less than 5.5-6cm)  σf becomes zero at a certain percentage below 10. These reasons are also discussed.