ABSTRACT
As gravity is the physical property which is concerned, the free surface of a still liquid is always horizontal and the pressure intensity is the same on any horizontal plane within the body of the liquid. Moreover, it may be shown that the pressure intensity on any elemental particle is the same in all directions. This follows from a consideration of the
pressure forces acting on an elemental triangular-shaped prism (Fig. 3.2) of unit horizontal length, with sectional dimensions 8/, 8x, 8y, and weight 8 W.
