Friedrich Soennecken developed a construction kit for uppercase letters for primary school children in 1913. Soennecken had been inspired by the pedagogue Froebel, who worked with building blocks based on the elementary shapes sphere, cube and pyramid. As a logical continuation Soennecken developed a writing system based on lines and circles. With his construction kit the children composed the characters from a set of straight and circular metal elements. An underlying grid helped the children to position the elements.
