Permanent magnets

These permanent magnets were used in the Physical Laboratory of Philips in Eindhoven. Each magnet has a specific property. For example, the cylinder-shaped magnet [236] is an alloy of chromium, nickel and steel, which ensures that the magnetism is retained for a long time. The total weight of this magnet is 420 grams, but it can carry 32 kilogram. The two other magnets [263] have such strong north poles (red) that they can repulse each other so much as to float the upper magnet. Finally, there is a magnet [284] consisting of two rings of permanent-magnetic earthenware (ferroxdure). The magnetic planes repulse each other so strongly as to float a ring. The magnets were donated by prof. dr G.W. Rathenau, director of Philips Physical Laboratory. From 1936 till 1938 he worked in Teylers Physical Laboratory.