Mathematics and art through the strings as with a bird cage and to see one form within another which excited me." The artists Theo van Doesburg and Piet Mondrian founded the De Stijl movement, which they wanted to "establish a visual vocabulary elementary geometrical forms comprehensible by all and adaptable to any discipline". Many of their artworks visibly consist of ruled squares and triangles, sometimes also with circles. De Stijl artists worked in painting, furniture, interior design and architecture. After the breakup of De Stijl, Van Doesburg founded the Avant-garde Art Concret movement, describing his 1929–1930 "Arithmetic Composition", a series of four black
Jef Van der Veken Hubert van Eyck and identified the Master of Flémalle with Rogier van der Weyden (current scholarship identifies the Master of Flémalle with Robert Campin, the teacher of Rogier van der Weyden). These publications aroused lively polemics with reputed art historians. At the 1935 World Exhibition in Brussels three works, of which the visible surface had been executed mainly by Van der Veken, where exhibited under the name of Rogier van der Weyden: one as an original work by van der Weyden (the Madonna with Child or 'Renders Madonna', now in the Museum of Fine Arts in Tournai) and two as