Solids of constant width

These machined solid aluminium shapes have the unusual property that, since their width is always 35mm no matter where you measure them, you can roll a flat object on top of three of the shapes and it rolls smoothly without wobbling up and down. One of the photographs shows a sheet of perspex sitting horizontally on top of the three shapes. Shapes of constant width are called Meissner’s bodies. Purchased in 2011 from www.grand-illusions.com.