1. It takes a minimum of 12 spokes to overcome the turbining evident with the minimum four vectors of restraint. This is demonstrated with the 12-spoke wire wheel with its six positive diaphragm and six negative diaphragm of which respectively three each are positively and negatively opposed turbining or torque members.
2. Two-axis "universal joints," analogous to the wire wheel as a basic principle relying on the independent differentiation of tension and compression for its effectiveness. These all may be considered basic tensegrity systems.

[Editor's note: The entry for "C" is omitted in the letter, though the initial "C." appears. In Fig. 6.61 of Cosmography, the caption for this item reads: "A strong tensional web, fabric, rubber, or leather disk may serve as a continuous tensional sheet between the opposed turbining or torque members." Fig. 6.61 omits the far left figure and the next to the right figure is elaborated with more components.]