An investigation is made of prestressed cable nets, treating them as discrete assemblages. Two essentially different methods are developed: the first, called a configuration theory, for determining the initial configuration of the system when in equilibrium with given loads, and the second, called a deformation theory, for determining the change in geometry contingent upon any change in the loading. The need for these techniques arises because geometrically significant mechanical movements of the joints can occur which cause the usual methods of structural analysis based on stiffness matrices to break down. The concept of mechanical freedom is examined and a method is derived for determining the degree of mechanical freedom of structural assemblies. These methods are then applied to the study of a small saddle-shaped net for which laboratory model verifications are available.