A discussion is given concerning the properties of superconductors considered as permanent magnets.Experiments on solid and hollow cylinders of lead are reported and compared to theoretical predictions. Amacroscopic theory is developed of the filamentary mesh high-field superconductor in the form of an infiniteplate. An experiment on a sample ofNb3Snshows maximum energy product greater than 25 MG-Oe at4.2°K. The phenomenon of discontinuous flux jumping is demonstrated and discussed briefly.