ANTI-MEISSNER EFFECT. Chill a superconductor in the presence of a magnetic field. At the critical temperature superconductivity happens---resistance drops to zero---but at first only in an archipelago of tiny islands at the material's surface. If the sample is smooth enough, which is the case at Andre Geim's lab (geim@sci.kun.nl) at the University of Nijmegen in the Netherlands, the superconductivity will extend uninterrupted all the way around the sample like a sheath 100 to 1000 atoms deep, trapping any magnetic flux that is in the sample. As the sample is cooled further the superconductivity regime takes over more and more of the interior, tightening the noose around the flux already inside. This in turn makes room for more flux to enter the outer precincts of the sample. In effect the sample attracts and promotes magnetism. This is an example of a paramagnetic (magnetic enhancement) Meissner effect, in contrast to the diamagnetic (magnetically neutralizing) Meissner effect customarily observed in superconductors. Geim's experiment, using micron-sized disks, is the first to measure this effect with a precision of better than one magnetic flux quantum. From his results, Geim argues two points: (1) that if samples have smooth enough surfaces the anti-Meissner effect would be more typical of superconductor behavior than the conventional Meissner effect; and (2) that since his sample is made of aluminum (a low-temperature superconductor) the anti-Meissner effect cannot be exclusive to high-temperature materials, suggesting that the effect cannot serve as direct evidence in favor of the idea that superconductivity in high-temperature materials is characterized by charge carriers that are so called d-wave Cooper pairs. (Nature, 12 November 1998.)