Joseph Beuys, Phosphorus-Cross Sled, 1972–77. Phosphorus between PVC plates with a metal clip. Collection of Institute of Contemporary Art, Miami. Anonymous Gift in Honor of Craig Robins. Joseph Beuys, Phosphorus-Cross Sled, 1972–77. Phosphorus between PVC plates with a metal clip. Collection of Institute of Contemporary Art, Miami. Anonymous Gift in Honor of Craig Robins.