In 1989 I made a drawing of a net on a cube, consisting of 12 lines/elements. They were connected in a way that, a couple of months later, I recognised them in 899v in Leonardo’s
. I don’t know which moment impressed me the most: my own discovery of a very simple and powerful connecting system or the discovery of the Leonardo drawings, which implied that my own discovery was in fact a rediscovery. What we see in Leonardo’s drawings are some examples of roof constructions built with a lot of straight elements. These drawings can be ‘translated’ into the following definition: On each element we define four points at some distance of each other — two points somewhere in the middle and two points closer to the ends. To make constructions with these elements we need only connect a middle point of one element to an end point of another one in a regular over-under pattern. Out of the simple definition of the elements, I designed many different patterns for my so-called “+ - - +” structures: domes, spheres, cylinders and other models were made.